Mercurial > dwindows

changeset 2557:756331246f94

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Android: Implement Java exception handling, make sure all return values from JNI are sane. This allows you to break in _dw_jni_check_exception() on or before return TRUE to catch any Java exceptions, otherwise they will be cleared and the functions will return failure. Fix the NullPointerException from the last commit, it was in windowGetData with a non existant key in the data SimpleArrayMap.
author bsmith@81767d24-ef19-dc11-ae90-00e081727c95
date Mon, 17 May 2021 21:11:40 +0000
parents d2d8c66ad062
children ebc6a4ff5f1f
files android/DWindows.kt android/dw.cpp
diffstat 2 files changed, 239 insertions(+), 84 deletions(-) [+]
line wrap: on
line diff
--- a/android/DWindows.kt	Sun May 16 22:41:50 2021 +0000
+++ b/android/DWindows.kt	Mon May 17 21:11:40 2021 +0000
@@ -824,7 +824,9 @@
         if (window.tag != null) {
             var dataArrayMap: SimpleArrayMap<String, Long> = window.tag as SimpleArrayMap<String, Long>
 
-            retval = dataArrayMap.get(name)!!
+            if(dataArrayMap.containsKey(name)) {
+                retval = dataArrayMap.get(name)!!
+            }
         }
         return retval
     }
--- a/android/dw.cpp	Sun May 16 22:41:50 2021 +0000
+++ b/android/dw.cpp	Mon May 17 21:11:40 2021 +0000
@@ -78,6 +78,42 @@
     return static_cast<jclass>(env->CallObjectMethod(_dw_class_loader, _dw_class_method, env->NewStringUTF(name)));
 }
 
+// Do a quick check if an exception occurred...
+// Display then clear it so we can continue...
+// Return TRUE if an exception had occurred
+int _dw_jni_check_exception(JNIEnv *env)
+{
+    if(env->ExceptionCheck())
+    {
+        env->ExceptionDescribe();
+        env->ExceptionClear();
+        return TRUE;
+    }
+    return FALSE;
+}
+
+#define _DW_REFERENCE_NONE   0
+#define _DW_REFERENCE_WEAK   1
+#define _DW_REFERENCE_STRONG 2
+
+// Handle returns from JNI functions and make sure the
+// return value is sane...
+// Reference: 0 no reference 1 weak 2 strong
+jobject _dw_jni_check_result(JNIEnv *env, jobject obj, int reference)
+{
+    jobject result = nullptr;
+
+    if(!_dw_jni_check_exception(env) && obj)
+    {
+        if(reference == 1)
+            result = env->NewWeakGlobalRef(obj);
+        else if(reference == 2)
+            result = env->NewGlobalRef(obj);
+        else
+            result = obj;
+    }
+    return result;
+}
 
 /* Call the dwmain entry point, Android has no args, so just pass the app path */
 void _dw_main_launch(char *arg)
@@ -592,6 +628,7 @@
 int _dw_dark_mode_detected()
 {
     JNIEnv *env;
+    int retval = DW_ERROR_UNKNOWN;
 
     if((env = (JNIEnv *)pthread_getspecific(_dw_env_key)))
     {
@@ -601,9 +638,10 @@
         jmethodID darkModeDetected = env->GetMethodID(clazz, "darkModeDetected",
                                                       "()I");
         // Call the method on the object
-        return env->CallIntMethod(_dw_obj, darkModeDetected);
-    }
-    return DW_ERROR_UNKNOWN;
+        retval = env->CallIntMethod(_dw_obj, darkModeDetected);
+        _dw_jni_check_exception(env);
+    }
+    return retval;
 }
 
 /*
@@ -622,6 +660,7 @@
                                             "()V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, dwMain);
+        _dw_jni_check_exception(env);
     }
 
     /* We don't actually run a loop here,
@@ -657,6 +696,7 @@
                                                   "(I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, mainSleep, milliseconds);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -689,6 +729,7 @@
                                                   "(I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, dwindowsExit, exitcode);
+        _dw_jni_check_exception(env);
     }
     // We shouldn't get here, but in case JNI can't call dwindowsExit...
     exit(exitcode);
@@ -788,6 +829,7 @@
                                                "(Ljava/lang/String;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, debugMessage, jstr);
+        _dw_jni_check_exception(env);
     }
     else {
         /* Output to stderr, if there is another way to send it
@@ -813,6 +855,7 @@
     va_list args;
     char outbuf[1025] = {0};
     JNIEnv *env;
+    int retval = 0;
 
     va_start(args, format);
     vsnprintf(outbuf, 1024, format, args);
@@ -829,9 +872,10 @@
         jmethodID messageBox = env->GetMethodID(clazz, "messageBox",
                                                   "(Ljava/lang/String;Ljava/lang/String;I)I");
         // Call the method on the object
-        return env->CallIntMethod(_dw_obj, messageBox, jstrtitle, jstr, flags);
-    }
-    return 0;
+        retval = env->CallIntMethod(_dw_obj, messageBox, jstrtitle, jstr, flags);
+        _dw_jni_check_exception(env);
+    }
+    return retval;
 }
 
 /*
@@ -849,6 +893,7 @@
 char * API dw_file_browse(const char *title, const char *defpath, const char *ext, int flags)
 {
     JNIEnv *env;
+    char *retval = nullptr;
 
     if((env = (JNIEnv *)pthread_getspecific(_dw_env_key)))
     {
@@ -866,11 +911,11 @@
         jmethodID fileBrowse = env->GetMethodID(clazz, "fileBrowse",
                                                 "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;I)Ljava/lang/String;");
         // Call the method on the object
-        jstring jresult = (jstring)env->CallObjectMethod(_dw_obj, fileBrowse, jstr, path, jext, flags);
+        jstring jresult = (jstring)_dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, fileBrowse, jstr, path, jext, flags), _DW_REFERENCE_NONE);
         if(jresult)
-            return strdup(env->GetStringUTFChars(jresult, nullptr));
-    }
-    return nullptr;
+            retval = strdup(env->GetStringUTFChars(jresult, nullptr));
+    }
+    return retval;
 }
 
 /*
@@ -895,7 +940,7 @@
         jmethodID clipboardGetText = env->GetMethodID(clazz, "clipboardGetText",
                                                       "()Ljava/lang/String;");
         // Call the method on the object
-        jstring result = (jstring)env->CallObjectMethod(_dw_obj, clipboardGetText);
+        jstring result = (jstring)_dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, clipboardGetText), _DW_REFERENCE_NONE);
         // Get the UTF8 string result
         if(result)
             utf8 = env->GetStringUTFChars(result, nullptr);
@@ -925,6 +970,7 @@
                                                       "(Ljava/lang/String;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, clipboardSetText, jstr);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1008,7 +1054,7 @@
         // Get the method that you want to call
         jmethodID boxNew = env->GetMethodID(clazz, "boxNew", "(II)Landroid/widget/LinearLayout;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, boxNew, type, pad));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, boxNew, type, pad), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1049,7 +1095,7 @@
         jmethodID scrollBoxNew = env->GetMethodID(clazz, "scrollBoxNew",
                                             "(II)Landroid/widget/ScrollView;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, scrollBoxNew, type, pad));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, scrollBoxNew, type, pad), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1094,6 +1140,7 @@
         jmethodID boxPack = env->GetMethodID(clazz, "boxPack", "(Landroid/view/View;Landroid/view/View;IIIIII)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, boxPack, box, item, index, width, height, hsize, vsize, pad);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1116,6 +1163,7 @@
         jmethodID boxUnpack = env->GetMethodID(clazz, "boxUnpack", "(Landroid/view/View;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, boxUnpack, handle);
+        _dw_jni_check_exception(env);
         return DW_ERROR_NONE;
     }
     return DW_ERROR_GENERAL;
@@ -1141,7 +1189,7 @@
         jmethodID boxUnpackAtIndex = env->GetMethodID(clazz, "boxUnpackAtIndex",
                                                       "(Landroid/widget/LinearLayout;I)Landroid/view/View;");
         // Call the method on the object
-        retval = env->CallObjectMethod(_dw_obj, boxUnpackAtIndex, box, index);
+        retval = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, boxUnpackAtIndex, box, index), _DW_REFERENCE_WEAK);
     }
     return retval;
 }
@@ -1220,7 +1268,7 @@
         jmethodID buttonNew = env->GetMethodID(clazz, "buttonNew",
                                                "(Ljava/lang/String;I)Landroid/widget/Button;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, buttonNew, jstr, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, buttonNew, jstr, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1240,7 +1288,7 @@
         jmethodID entryfieldNew = env->GetMethodID(clazz, "entryfieldNew",
                                                    "(Ljava/lang/String;II)Landroid/widget/EditText;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, entryfieldNew, jstr, (int)cid, password));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, entryfieldNew, jstr, (int)cid, password), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1290,6 +1338,7 @@
                                                         "(Landroid/widget/EditText;J)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, entryfieldSetLimit, handle, (jlong)limit);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1315,7 +1364,7 @@
         jmethodID bitmapButtonNew = env->GetMethodID(clazz, "bitmapButtonNew",
                                                      "(Ljava/lang/String;I)Landroid/widget/ImageButton;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, bitmapButtonNew, jstr, (int)resid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, bitmapButtonNew, jstr, (int)resid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1347,7 +1396,7 @@
         jmethodID bitmapButtonNewFromFile = env->GetMethodID(clazz, "bitmapButtonNewFromFile",
                                                              "(Ljava/lang/String;ILjava/lang/String;)Landroid/widget/ImageButton;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, bitmapButtonNewFromFile, jstr, (int)cid, path));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, bitmapButtonNewFromFile, jstr, (int)cid, path), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1381,7 +1430,7 @@
         jmethodID bitmapButtonNewFromData = env->GetMethodID(clazz, "bitmapButtonNewFromData",
                                                              "(Ljava/lang/String;I[BI)Landroid/widget/ImageButton;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, bitmapButtonNewFromData, jstr, (int)cid, bytearray, len));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, bitmapButtonNewFromData, jstr, (int)cid, bytearray, len), _DW_REFERENCE_WEAK);
         // Clean up after the array now that we are finished
         //env->ReleaseByteArrayElements(bytearray, (jbyte *) data, 0);
         return result;
@@ -1411,7 +1460,7 @@
         jmethodID spinButtonNew = env->GetMethodID(clazz, "spinButtonNew",
                                                    "(Ljava/lang/String;I)Lorg/dbsoft/dwindows/DWSpinButton;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, spinButtonNew, jstr, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, spinButtonNew, jstr, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1436,6 +1485,7 @@
                                                       "(Lorg/dbsoft/dwindows/DWSpinButton;J)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, spinButtonSetPos, handle, (jlong)position);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1459,6 +1509,7 @@
                                                          "(Lorg/dbsoft/dwindows/DWSpinButton;JJ)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, spinButtonSetLimits, handle, (jlong)upper, (jlong)lower);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1483,6 +1534,8 @@
                                                       "(Lorg/dbsoft/dwindows/DWSpinButton;)J");
         // Call the method on the object
         retval = env->CallLongMethod(_dw_obj, spinButtonGetPos, handle);
+        if(_dw_jni_check_exception(env))
+            retval = 0;
     }
     return retval;
 }
@@ -1509,7 +1562,7 @@
         jmethodID radioButtonNew = env->GetMethodID(clazz, "radioButtonNew",
                                                     "(Ljava/lang/String;I)Landroid/widget/RadioButton;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, radioButtonNew, jstr, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, radioButtonNew, jstr, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1535,7 +1588,7 @@
         // Get the method that you want to call
         jmethodID sliderNew = env->GetMethodID(clazz, "sliderNew", "(III)Landroid/widget/SeekBar;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, sliderNew, vertical, increments, (jint)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, sliderNew, vertical, increments, (jint)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1551,6 +1604,7 @@
 unsigned int API dw_slider_get_pos(HWND handle)
 {
     JNIEnv *env;
+    unsigned int retval = 0;
 
     if(handle && (env = (JNIEnv *)pthread_getspecific(_dw_env_key)))
     {
@@ -1560,9 +1614,11 @@
         jmethodID percentGetPos = env->GetMethodID(clazz, "percentGetPos",
                                                    "(Landroid/widget/ProgressBar;)I");
         // Call the method on the object
-        return env->CallIntMethod(_dw_obj, percentGetPos, handle);
-    }
-    return 0;
+        retval = env->CallIntMethod(_dw_obj, percentGetPos, handle);
+        if(_dw_jni_check_exception(env))
+            retval = 0;
+    }
+    return retval;
 }
 
 /*
@@ -1632,6 +1688,7 @@
                                                      "(Landroid/widget/ProgressBar;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, percentSetRange, handle, (jint)range);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1654,7 +1711,7 @@
         jmethodID percentNew = env->GetMethodID(clazz, "percentNew",
                                                "(I)Landroid/widget/ProgressBar;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, percentNew, (jint)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, percentNew, (jint)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1679,6 +1736,7 @@
                                                    "(Landroid/widget/ProgressBar;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, percentSetPos, handle, (jint)position);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1704,7 +1762,7 @@
         jmethodID checkboxNew = env->GetMethodID(clazz, "checkboxNew",
                                                  "(Ljava/lang/String;I)Landroid/widget/CheckBox;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, checkboxNew, jstr, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, checkboxNew, jstr, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1720,6 +1778,7 @@
 int API dw_checkbox_get(HWND handle)
 {
     JNIEnv *env;
+    int retval = FALSE;
 
     if(handle && (env = (JNIEnv *)pthread_getspecific(_dw_env_key)))
     {
@@ -1729,9 +1788,11 @@
         jmethodID checkOrRadioGetChecked = env->GetMethodID(clazz, "checkOrRadioGetChecked",
                                                             "(Landroid/view/View;)Z");
         // Call the method on the object
-        return env->CallBooleanMethod(_dw_obj, checkOrRadioGetChecked, handle);
-    }
-    return FALSE;
+        retval = env->CallBooleanMethod(_dw_obj, checkOrRadioGetChecked, handle);
+        if(_dw_jni_check_exception(env))
+            retval = FALSE;
+    }
+    return retval;
 }
 
 /*
@@ -1753,6 +1814,7 @@
                                                             "(Landroid/view/View;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, checkOrRadioSetChecked, handle, value);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1776,7 +1838,7 @@
         jmethodID listBoxNew = env->GetMethodID(clazz, "listBoxNew",
                                                  "(II)Lorg/dbsoft/dwindows/DWListBox;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, listBoxNew, (int)cid, multi));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, listBoxNew, (int)cid, multi), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -1803,6 +1865,7 @@
                                                           "(Landroid/view/View;Ljava/lang/String;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, listOrComboBoxAppend, handle, jstr);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1828,6 +1891,7 @@
                                                           "(Landroid/view/View;Ljava/lang/String;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, listOrComboBoxInsert, handle, jstr, pos);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1865,6 +1929,7 @@
                                                           "(Landroid/view/View;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, listOrComboBoxClear, handle);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1889,6 +1954,8 @@
                                                          "(Landroid/view/View;)I");
         // Call the method on the object
         retval = env->CallIntMethod(_dw_obj, listOrComboBoxCount, handle);
+        if(_dw_jni_check_exception(env))
+            retval = 0;
     }
     return retval;
 }
@@ -1912,6 +1979,7 @@
                                                          "(Landroid/view/View;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, listBoxSetTop, handle, top);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1935,7 +2003,7 @@
         jmethodID listOrComboBoxGetText = env->GetMethodID(clazz, "listOrComboBoxGetText",
                                                            "(Landroid/view/View;I)Ljava/lang/String;");
         // Call the method on the object
-        jstring result = (jstring)env->CallObjectMethod(_dw_obj, listOrComboBoxGetText, handle, index);
+        jstring result = (jstring)_dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, listOrComboBoxGetText, handle, index), _DW_REFERENCE_NONE);
         // Get the UTF8 string result
         if(result)
         {
@@ -1968,6 +2036,7 @@
                                                           "(Landroid/view/View;ILjava/lang/String;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, listOrComboBoxSetText, handle, index, jstr);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -1992,6 +2061,8 @@
                                                            "(Landroid/view/View;)I");
         // Call the method on the object
         retval = env->CallIntMethod(_dw_obj, listOrComboBoxGetSelected, handle);
+        if(_dw_jni_check_exception(env))
+            retval = DW_ERROR_UNKNOWN;
     }
     return retval;
 }
@@ -2018,6 +2089,8 @@
                                                           "(Landroid/view/View;I)I");
         // Call the method on the object
         retval = env->CallIntMethod(_dw_obj, listBoxSelectedMulti, handle, where);
+        if(_dw_jni_check_exception(env))
+            retval = DW_ERROR_UNKNOWN;
     }
     return retval;
 }
@@ -2042,6 +2115,7 @@
                                                            "(Landroid/view/View;II)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, listOrComboBoxSelect, handle, index, state);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2064,6 +2138,7 @@
                                                           "(Landroid/view/View;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, listOrComboBoxDelete, handle, index);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2089,7 +2164,7 @@
         jmethodID comboBoxNew = env->GetMethodID(clazz, "comboBoxNew",
                                                  "(Ljava/lang/String;I)Lorg/dbsoft/dwindows/DWComboBox;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, comboBoxNew, jstr, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, comboBoxNew, jstr, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -2114,7 +2189,7 @@
         jmethodID mleNew = env->GetMethodID(clazz, "mleNew",
                                             "(I)Landroid/widget/EditText;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, mleNew, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, mleNew, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -2145,6 +2220,8 @@
                                                "(Landroid/widget/EditText;Ljava/lang/String;I)I");
         // Call the method on the object
         retval = env->CallIntMethod(_dw_obj, mleImport, handle, jstr, startpoint);
+        if(_dw_jni_check_exception(env))
+            retval = 0;
     }
     return retval;
 }
@@ -2230,6 +2307,7 @@
                                                "(Landroid/widget/EditText;II)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, mleDelete, handle, startpoint, length);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2251,6 +2329,7 @@
                                               "(Landroid/widget/EditText;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, mleClear, handle);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2283,6 +2362,7 @@
                                                     "(Landroid/widget/EditText;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, mleSetEditable, handle, state);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2305,6 +2385,7 @@
                                                     "(Landroid/widget/EditText;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, mleSetWordWrap, handle, state);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2327,6 +2408,7 @@
                                                     "(Landroid/widget/EditText;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, mleSetWordWrap, handle, point);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2387,7 +2469,7 @@
         jmethodID textNew = env->GetMethodID(clazz, "textNew",
                                              "(Ljava/lang/String;II)Landroid/widget/TextView;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, textNew, jstr, (int)cid, status));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, textNew, jstr, (int)cid, status), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -2438,7 +2520,7 @@
         jmethodID renderNew = env->GetMethodID(clazz, "renderNew",
                                                "(I)Lorg/dbsoft/dwindows/DWRender;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, renderNew, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, renderNew, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -2462,6 +2544,7 @@
                                                   "(Lorg/dbsoft/dwindows/DWRender;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, renderRedraw, handle);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2486,6 +2569,7 @@
                                               "(IIII)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, colorSet, 0, (jint)DW_RED_VALUE(color), (jint)DW_GREEN_VALUE(color), (jint)DW_BLUE_VALUE(color));
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2510,6 +2594,7 @@
                                               "(IIII)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, bgColorSet, 0, (jint)DW_RED_VALUE(color), (jint)DW_GREEN_VALUE(color), (jint)DW_BLUE_VALUE(color));
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2544,6 +2629,7 @@
                                                "(Lorg/dbsoft/dwindows/DWRender;Landroid/graphics/Bitmap;II)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, drawPoint, handle, pixmap ? pixmap->bitmap : nullptr, x, y);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2569,6 +2655,7 @@
                                               "(Lorg/dbsoft/dwindows/DWRender;Landroid/graphics/Bitmap;IIII)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, drawLine, handle, pixmap ? pixmap->bitmap : nullptr, x1, y1, x2, y2);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2596,6 +2683,7 @@
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, drawLine, handle, pixmap ? pixmap->bitmap : nullptr, x, y, jstr,
                             pixmap ? pixmap->typeface : nullptr, pixmap ? pixmap->fontsize : 0, pixmap ? pixmap->handle : nullptr);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2623,6 +2711,8 @@
         // Call the method on the object
         jlong dimensions = env->CallLongMethod(_dw_obj, fontTextExtentsGet, handle, pixmap ? pixmap->bitmap : nullptr, jstr,
                             pixmap ? pixmap->typeface : nullptr, pixmap ? pixmap->fontsize : 0, pixmap ? pixmap->handle : nullptr);
+        if(_dw_jni_check_exception(env))
+            dimensions = 0;
 
         if(width)
             *width = dimensions & 0xFFFF;
@@ -2661,6 +2751,7 @@
                                                      "(Lorg/dbsoft/dwindows/DWRender;Landroid/graphics/Bitmap;II[I[I)V");
             // Call the method on the object
             env->CallVoidMethod(_dw_obj, drawPolygon, handle, pixmap ? pixmap->bitmap : nullptr, flags, npoints, jx, jy);
+            _dw_jni_check_exception(env);
         }
     }
 }
@@ -2688,6 +2779,7 @@
                                               "(Lorg/dbsoft/dwindows/DWRender;Landroid/graphics/Bitmap;IIII)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, drawLine, handle, pixmap ? pixmap->bitmap : nullptr, x, y, width, height);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2717,6 +2809,7 @@
                                               "(Lorg/dbsoft/dwindows/DWRender;Landroid/graphics/Bitmap;IIIIIII)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, drawLine, handle, pixmap ? pixmap->bitmap : nullptr, flags, xorigin, yorigin, x1, y1, x2, y2);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -2897,7 +2990,7 @@
         jmethodID containerNew = env->GetMethodID(clazz, "containerNew",
                                                   "(II)Landroid/widget/ListView;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, containerNew, (int)cid, multi));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, containerNew, (int)cid, multi), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -2936,6 +3029,7 @@
                                                           "(Landroid/widget/ListView;Ljava/lang/String;I)V");
                 // Call the method on the object
                 env->CallVoidMethod(_dw_obj, containerNew, handle, jstr, (int)flags[z]);
+                _dw_jni_check_exception(env);
             }
         }
     }
@@ -2965,7 +3059,7 @@
 int API dw_filesystem_setup(HWND handle, unsigned long *flags, char **titles, int count)
 {
     unsigned long fsflags[2] = { DW_CFA_BITMAPORICON, DW_CFA_STRING };
-    char *fstitles[2] = { "Icon", "Filename" };
+    char *fstitles[2] = { (char *)"Icon", (char *)"Filename" };
     dw_container_setup(handle, fsflags, fstitles, 2, 0);
     dw_container_setup(handle, flags, titles, count, 0);
     return DW_ERROR_GENERAL;
@@ -2991,7 +3085,7 @@
         jmethodID containerAlloc = env->GetMethodID(clazz, "containerAlloc",
                                                     "(Landroid/widget/ListView;I)Landroid/widget/ListView;");
         // Call the method on the object
-        return (void *)env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, containerAlloc, handle, rowcount));
+        return (void *)_dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, containerAlloc, handle, rowcount), _DW_REFERENCE_WEAK);
     }
     return nullptr;
 }
@@ -3041,6 +3135,7 @@
                                                                  "(Landroid/widget/ListView;IILandroid/graphics/drawable/Drawable;)V");
                 // Call the method on the object
                 env->CallVoidMethod(_dw_obj, containerChangeItem, handle, column, row, icon);
+                _dw_jni_check_exception(env);
             }
         }
         else if((columntype & DW_CFA_STRING))
@@ -3057,6 +3152,7 @@
                                                                  "(Landroid/widget/ListView;IILjava/lang/String;)V");
                 // Call the method on the object
                 env->CallVoidMethod(_dw_obj, containerChangeItem, handle, column, row, jstr);
+                _dw_jni_check_exception(env);
             }
         }
         else if((columntype & DW_CFA_ULONG))
@@ -3069,6 +3165,7 @@
                                                              "(Landroid/widget/ListView;III)V");
             // Call the method on the object
             env->CallVoidMethod(_dw_obj, containerChangeItem, handle, column, row, (int)num);
+            _dw_jni_check_exception(env);
         }
         // TODO: Handle DATE and TIME
     }
@@ -3164,6 +3261,7 @@
 int API dw_container_get_column_type(HWND handle, int column)
 {
     JNIEnv *env;
+    int retval = 0;
 
     if((env = (JNIEnv *)pthread_getspecific(_dw_env_key)))
     {
@@ -3173,9 +3271,11 @@
         jmethodID containerGetColumnType = env->GetMethodID(clazz, "containerGetColumnType",
                                                             "(Landroid/widget/ListView;I)I");
         // Call the method on the object
-        return env->CallIntMethod(_dw_obj, containerGetColumnType, handle, column);
-    }
-    return 0;
+        retval = env->CallIntMethod(_dw_obj, containerGetColumnType, handle, column);
+        if(_dw_jni_check_exception(env))
+            retval = 0;
+    }
+    return retval;
 }
 
 /*
@@ -3273,6 +3373,7 @@
                                                     "(Landroid/widget/ListView;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, containerClear, handle);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -3421,8 +3522,8 @@
         jmethodID iconNew = env->GetMethodID(clazz, "iconNew",
                                              "(Ljava/lang/String;[BII)Landroid/graphics/drawable/Drawable;");
         // Call the method on the object
-        jobject result = env->NewGlobalRef(env->CallObjectMethod(_dw_obj, iconNew,
-                                                                 file, bytearray, len, resid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, iconNew,
+                                              file, bytearray, len, resid), _DW_REFERENCE_WEAK);
         // Clean up after the array now that we are finished
         //if(bytearray)
         //env->ReleaseByteArrayElements(bytearray, (jbyte *) data, 0);
@@ -3558,7 +3659,7 @@
         jmethodID mleNew = env->GetMethodID(clazz, "bitmapNew",
                                             "(I)Landroid/widget/ImageView;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, mleNew, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, mleNew, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -3582,19 +3683,25 @@
             bytearray = env->NewByteArray(len);
             env->SetByteArrayRegion(bytearray, 0, len, reinterpret_cast<const jbyte *>(data));
         }
-        // First get the class that contains the method you need to call
-        jclass clazz = _dw_find_class(env, DW_CLASS_NAME);
-        // Get the method that you want to call
-        jmethodID pixmapNew = env->GetMethodID(clazz, "pixmapNew",
-                                               "(IILjava/lang/String;[BII)Landroid/graphics/Bitmap;");
-        // Call the method on the object
-        jobject result = env->NewGlobalRef(env->CallObjectMethod(_dw_obj, pixmapNew,
-                                                                  (jint)width, (jint)height,
-                                                                  file, bytearray, len, resid));
-        // Clean up after the array now that we are finished
-        //if(bytearray)
+        if(!_dw_jni_check_exception(env))
+        {
+            // First get the class that contains the method you need to call
+            jclass clazz = _dw_find_class(env, DW_CLASS_NAME);
+            // Get the method that you want to call
+            jmethodID pixmapNew = env->GetMethodID(clazz, "pixmapNew",
+                                                   "(IILjava/lang/String;[BII)Landroid/graphics/Bitmap;");
+            // Call the method on the object
+            jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, pixmapNew,
+                                                                             (jint) width,
+                                                                             (jint) height,
+                                                                             file, bytearray, len,
+                                                                             resid),
+                                                  _DW_REFERENCE_STRONG);
+            // Clean up after the array now that we are finished
+            //if(bytearray)
             //env->ReleaseByteArrayElements(bytearray, (jbyte *) data, 0);
-        return result;    
+            return result;
+        }
     }
     return nullptr;
 }
@@ -3612,6 +3719,8 @@
                                                          "(Landroid/graphics/Bitmap;)J");
         // Call the method on the object
         jlong dimensions = env->CallLongMethod(_dw_obj, pixmapGetDimensions, pixmap->bitmap);
+        if(_dw_jni_check_exception(env))
+            dimensions = 0;
 
         pixmap->width = dimensions & 0xFFFF;
         pixmap->height = (dimensions >> 32) & 0xFFFF;
@@ -3775,7 +3884,7 @@
         jmethodID typefaceFromFontName = env->GetMethodID(clazz, "typefaceFromFontName",
                                                           "(Ljava/lang/String;)Landroid/graphics/Typeface;");
         // Call the method on the object
-        jobject typeface = env->NewGlobalRef(env->CallObjectMethod(_dw_obj, typefaceFromFontName, jstr));
+        jobject typeface = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, typefaceFromFontName, jstr), _DW_REFERENCE_STRONG);
         if(typeface)
         {
             jobject oldtypeface = pixmap->typeface;
@@ -3804,6 +3913,8 @@
         if(pixmap && (env = (JNIEnv *)pthread_getspecific(_dw_env_key)))
         {
             env->DeleteGlobalRef(pixmap->bitmap);
+            if(pixmap->typeface)
+                env->DeleteGlobalRef(pixmap->typeface);
             free(pixmap);
         }
     }
@@ -3860,6 +3971,8 @@
                                                   "(Lorg/dbsoft/dwindows/DWRender;Landroid/graphics/Bitmap;IIIILorg/dbsoft/dwindows/DWRender;Landroid/graphics/Bitmap;IIII)I");
         // Call the method on the object
         retval = env->CallIntMethod(_dw_obj, pixmapBitBlt, dest, destp ? destp->bitmap : nullptr, xdest, ydest, width, height, src, srcp ? srcp->bitmap : nullptr, xsrc, ysrc, srcwidth, srcheight);
+        if(_dw_jni_check_exception(env))
+            retval = DW_ERROR_GENERAL;
     }
     return retval;
 }
@@ -3883,7 +3996,7 @@
         jmethodID calendarNew = env->GetMethodID(clazz, "calendarNew",
                                                  "(I)Landroid/widget/CalendarView;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, calendarNew, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, calendarNew, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -3917,6 +4030,7 @@
                                                      "(Landroid/widget/CalendarView;J)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, calendarSetDate, handle, (jlong)date);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -3944,6 +4058,8 @@
                                                      "(Landroid/widget/CalendarView;)J");
         // Call the method on the object
         date = (time_t)env->CallLongMethod(_dw_obj, calendarGetDate, handle);
+        if(_dw_jni_check_exception(env))
+            date = 0;
         ts = *localtime(&date);
         if(year)
             *year = ts.tm_year + 1900;
@@ -3973,6 +4089,7 @@
                                                 "(Landroid/webkit/WebView;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, htmlAction, handle, action);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -4000,7 +4117,8 @@
                                                  "(Landroid/webkit/WebView;Ljava/lang/String;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, htmlRaw, handle, jstr);
-        return DW_ERROR_NONE;
+        if(!_dw_jni_check_exception(env))
+            return DW_ERROR_NONE;
     }
     return DW_ERROR_GENERAL;
 }
@@ -4029,7 +4147,8 @@
                                                  "(Landroid/webkit/WebView;Ljava/lang/String;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, htmlLoadURL, handle, jstr);
-        return DW_ERROR_NONE;
+        if(!_dw_jni_check_exception(env))
+            return DW_ERROR_NONE;
     }
     return DW_ERROR_GENERAL;
 }
@@ -4059,7 +4178,8 @@
                                                        "(Landroid/webkit/WebView;Ljava/lang/String;J)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, htmlJavascriptRun, handle, jstr, (jlong)scriptdata);
-        return DW_ERROR_NONE;
+        if(!_dw_jni_check_exception(env))
+            return DW_ERROR_NONE;
     }
     return DW_ERROR_UNKNOWN;
 }
@@ -4083,7 +4203,7 @@
         jmethodID htmlNew = env->GetMethodID(clazz, "htmlNew",
                                              "(I)Landroid/webkit/WebView;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, htmlNew, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, htmlNew, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -4128,7 +4248,7 @@
         jmethodID menuNew = env->GetMethodID(clazz, "menuNew",
                                              "(I)Lorg/dbsoft/dwindows/DWMenu;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, menuNew, (int)cid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, menuNew, (int)cid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -4153,7 +4273,7 @@
         jmethodID menuBarNew = env->GetMethodID(clazz, "menuBarNew",
                                                 "(Landroid/view/View;)Lorg/dbsoft/dwindows/DWMenu;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, menuBarNew, location));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, menuBarNew, location), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -4177,6 +4297,7 @@
                                                  "(Lorg/dbsoft/dwindows/DWMenu;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, menuDestroy, *menu);
+        _dw_jni_check_exception(env);
         *menu = nullptr;
     }
 }
@@ -4202,7 +4323,8 @@
                                                     "(Lorg/dbsoft/dwindows/DWMenu;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, menuDeleteItem, menux, (int)id);
-        return DW_ERROR_NONE;
+        if(!_dw_jni_check_exception(env))
+            return DW_ERROR_NONE;
     }
     return DW_ERROR_UNKNOWN;
 }
@@ -4269,7 +4391,7 @@
         jmethodID menuAppendItem = env->GetMethodID(clazz, "menuAppendItem",
                                                     "(Lorg/dbsoft/dwindows/DWMenu;Ljava/lang/String;IIIILorg/dbsoft/dwindows/DWMenu;)Lorg/dbsoft/dwindows/DWMenuItem;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, menuAppendItem, menux, jstr, (int)itemid, (int)flags, end, check, submenux));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, menuAppendItem, menux, jstr, (int)itemid, (int)flags, end, check, submenux), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -4309,6 +4431,7 @@
                                                   "(Lorg/dbsoft/dwindows/DWMenu;II)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, menuSetState, menux, (int)itemid, (int)state);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -4332,7 +4455,7 @@
         jmethodID notebookNew = env->GetMethodID(clazz, "notebookNew",
                                                  "(II)Landroid/widget/RelativeLayout;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, notebookNew, (int)cid, top));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, notebookNew, (int)cid, top), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -4361,6 +4484,8 @@
                                                      "(Landroid/widget/RelativeLayout;JI)J");
         // Call the method on the object
         result = (unsigned long)env->CallLongMethod(_dw_obj, notebookPageNew, handle, (jlong)flags, front);
+        if(_dw_jni_check_exception(env))
+            result = 0;
     }
     return result;
 }
@@ -4384,6 +4509,7 @@
                                                          "(Landroid/widget/RelativeLayout;J)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, notebookPageDestroy, handle, (jlong)pageid);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -4407,6 +4533,8 @@
                                                      "(Landroid/widget/RelativeLayout;)J");
         // Call the method on the object
         result = (unsigned long)env->CallLongMethod(_dw_obj, notebookPageGet, handle);
+        if(_dw_jni_check_exception(env))
+            result = 0;
     }
     return result;
 }
@@ -4429,6 +4557,7 @@
                                                      "(Landroid/widget/RelativeLayout;J)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, notebookPageSet, handle, (jlong)pageid);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -4454,6 +4583,7 @@
                                                          "(Landroid/widget/RelativeLayout;JLjava/lang/String;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, notebookPageSetText, handle, (jlong)pageid, jstr);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -4488,6 +4618,7 @@
                                                       "(Landroid/widget/RelativeLayout;JLandroid/widget/LinearLayout;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, notebookPagePack, handle, (jlong)pageid, page);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -4514,7 +4645,7 @@
         jmethodID windowNew = env->GetMethodID(clazz, "windowNew",
                                                "(Ljava/lang/String;I)Landroid/widget/LinearLayout;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, windowNew, jstr, (int)flStyle));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, windowNew, jstr, (int)flStyle), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -4555,7 +4686,8 @@
                                                     "(Landroid/view/View;I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, windowHideShow, handle, state);
-        return DW_ERROR_NONE;
+        if(!_dw_jni_check_exception(env))
+            return DW_ERROR_NONE;
     }
     return DW_ERROR_GENERAL;
 }
@@ -4611,7 +4743,8 @@
         env->CallVoidMethod(_dw_obj, windowSetColor, handle,
                             (jint)fore, 0, (jint)DW_RED_VALUE(_fore), (jint)DW_GREEN_VALUE(_fore), (jint)DW_BLUE_VALUE(_fore),
                             (jint)back, 0, (jint)DW_RED_VALUE(_back), (jint)DW_GREEN_VALUE(_back), (jint)DW_BLUE_VALUE(_back));
-        return DW_ERROR_NONE;
+        if(!_dw_jni_check_exception(env))
+            return DW_ERROR_NONE;
     }
     return DW_ERROR_GENERAL;
 }
@@ -4722,7 +4855,8 @@
                                                     "(Landroid/view/View;Ljava/lang/String;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, windowHideShow, handle, jstr);
-        return DW_ERROR_NONE;
+        if(!_dw_jni_check_exception(env))
+            return DW_ERROR_NONE;
     }
     return DW_ERROR_GENERAL;
 }
@@ -4792,7 +4926,7 @@
         jmethodID windowGetText = env->GetMethodID(clazz, "windowGetText",
                                                    "(Landroid/view/View;)Ljava/lang/String;");
         // Call the method on the object
-        jstring result = (jstring)env->CallObjectMethod(_dw_obj, windowGetText, handle);
+        jstring result = (jstring)_dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, windowGetText, handle), _DW_REFERENCE_NONE);
         // Get the UTF8 string result
         if(result)
             utf8 = env->GetStringUTFChars(result, nullptr);
@@ -4822,6 +4956,7 @@
                                                    "(Landroid/view/View;Ljava/lang/String;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, windowSetText, handle, jstr);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -4848,6 +4983,7 @@
                                                       "(Landroid/view/View;Z)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, windowSetEnabled, handle, state);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -4902,6 +5038,7 @@
                                                              "(Landroid/view/View;I[BI)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, windowSetBitmapFromData, handle, (int)cid, bytearray, len);
+        _dw_jni_check_exception(env);
         // Clean up after the array now that we are finished
         //if(bytearray)
             //env->ReleaseByteArrayElements(bytearray, (jbyte *) data, 0);
@@ -4936,6 +5073,7 @@
                                                              "(Landroid/view/View;ILjava/lang/String;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, windowSetBitmapFromData, handle, (int)resid, jstr);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -4970,7 +5108,7 @@
         jmethodID windowFromId = env->GetMethodID(clazz, "windowFromId",
                                                   "(Landroid/view/View;I)Landroid/view/View;");
         // Call the method on the object
-        retval = env->CallObjectMethod(_dw_obj, windowFromId, handle, id);
+        retval = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, windowFromId, handle, id), _DW_REFERENCE_NONE);
     }
     return retval;
 }
@@ -5110,6 +5248,8 @@
                                                              "()J");
             // Call the method on the object
             _dw_screen_dimensions = env->CallLongMethod(_dw_obj, screenGetDimensions);
+            if(_dw_jni_check_exception(env))
+                _dw_screen_dimensions = 0;
         }
     }
     return _dw_screen_dimensions & 0xFFFF;
@@ -5133,6 +5273,8 @@
                                                              "()J");
             // Call the method on the object
             _dw_screen_dimensions = env->CallLongMethod(_dw_obj, screenGetDimensions);
+            if(_dw_jni_check_exception(env))
+                _dw_screen_dimensions = 0;
         }
     }
     return (_dw_screen_dimensions >> 32) & 0xFFFF;
@@ -5166,7 +5308,7 @@
             jmethodID androidGetRelease = jenv->GetMethodID(clazz, "androidGetRelease",
                                                            "()Ljava/lang/String;");
             // Call the method on the object
-            jstring jstr = (jstring)jenv->CallObjectMethod(_dw_obj, androidGetRelease);
+            jstring jstr = (jstring)_dw_jni_check_result(jenv, jenv->CallObjectMethod(_dw_obj, androidGetRelease), _DW_REFERENCE_NONE);
 
             if(jstr)
                 release = jenv->GetStringUTFChars(jstr, nullptr);
@@ -5208,6 +5350,7 @@
         jmethodID doBeep = env->GetMethodID(clazz, "doBeep", "(I)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, doBeep, dur);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -5240,6 +5383,7 @@
                                                    "(Landroid/view/View;Ljava/lang/String;J)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, windowSetData, window, jstr, (jlong)data);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -5267,6 +5411,8 @@
                                                    "(Landroid/view/View;Ljava/lang/String;)J");
         // Call the method on the object
         retval = (void *)env->CallLongMethod(_dw_obj, windowGetData, window, jstr);
+        if(_dw_jni_check_exception(env))
+            retval = nullptr;
     }
     return retval;
 }
@@ -5316,8 +5462,8 @@
         jmethodID timerConnect = env->GetMethodID(clazz, "timerConnect",
                                                   "(JJJ)Ljava/util/Timer;");
         // Call the method on the object
-        retval = DW_POINTER_TO_INT(env->NewGlobalRef(env->CallObjectMethod(_dw_obj,
-                                    timerConnect, longinterval, (jlong)sigfunc, (jlong)data)));
+        retval = DW_POINTER_TO_INT(_dw_jni_check_result(env, env->CallObjectMethod(_dw_obj,
+                                    timerConnect, longinterval, (jlong)sigfunc, (jlong)data), _DW_REFERENCE_STRONG));
     }
     return retval;
 }
@@ -5342,6 +5488,7 @@
                                                      "(Ljava/util/Timer;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, timerDisconnect, timer);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -5620,7 +5767,7 @@
 int _dw_is_ui_thread(void)
 {
     JNIEnv *env;
-
+    int retval = FALSE;
     if((env = (JNIEnv *)pthread_getspecific(_dw_env_key)))
     {
         // First get the class that contains the method you need to call
@@ -5629,9 +5776,11 @@
         jmethodID isUIThread = env->GetMethodID(clazz, "isUIThread",
                                                 "()Z");
         // Call the method on the object
-        return env->CallBooleanMethod(_dw_obj, isUIThread);
-    }
-    return FALSE;
+        retval = env->CallBooleanMethod(_dw_obj, isUIThread);
+        if(_dw_jni_check_exception(env))
+            retval = FALSE;
+    }
+    return retval;
 }
 
 /*
@@ -6367,6 +6516,8 @@
                                             "(Ljava/lang/String;Ljava/lang/String;)I");
         // Call the method on the object
         _dw_android_api = env->CallIntMethod(_dw_obj, dwInit, appid, appname);
+        if(_dw_jni_check_exception(env))
+            _dw_android_api = 0;
     }
     return DW_ERROR_NONE;
 }
@@ -6387,6 +6538,7 @@
                                                       "()V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, dwindowsShutdown);
+        _dw_jni_check_exception(env);
     }
 }
 
@@ -6502,7 +6654,7 @@
         jmethodID notificationNew = env->GetMethodID(clazz, "notificationNew",
                                                      "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Landroidx/core/app/NotificationCompat$Builder;");
         // Call the method on the object
-        jobject result = env->NewWeakGlobalRef(env->CallObjectMethod(_dw_obj, notificationNew, ntitle, image, ndesc, appid));
+        jobject result = _dw_jni_check_result(env, env->CallObjectMethod(_dw_obj, notificationNew, ntitle, image, ndesc, appid), _DW_REFERENCE_WEAK);
         return result;
     }
     return nullptr;
@@ -6528,7 +6680,8 @@
                                                      "(Landroidx/core/app/NotificationCompat$Builder;)V");
         // Call the method on the object
         env->CallVoidMethod(_dw_obj, notificationNew, notification);
-        return DW_ERROR_NONE;
+        if(!_dw_jni_check_exception(env))
+            return DW_ERROR_NONE;
     }
     return DW_ERROR_UNKNOWN;
 }