Can't catch Java (Android) Exception with try-catch
Solution 1
There are two classes to catch the problems.
- Error
- Exception
Both are sub-class of Throwable class. When there is situation we do not know, that particular code block will throw Exception or Error? You can use Throwable. Throwable will catch both Errors & Exceptions.
Do this way
try {
u.save();
} catch (Throwable e) {
e.printStackTrace();
}
Solution 2
do this way
try {
// do some thing which you want in try block
} catch (JSONException e) {
e.printStackTrace();
Log.e("Catch block", Log.getStackTraceString(e));
}
Solution 3
Constraint failed usually indicates that you did something like pass a null
value into a column that you declare as not null
when you create your table.
kramer65
Updated on September 21, 2020Comments
-
kramer65 over 3 years
I'm a Java (Android) beginner (coming from Python) and I'm trying to catch an exception using Try-Catch as follows:
try { u.save(); } catch (Exception e) { Log.wtf("DO THIS", " WHEN SAVE() FAILS"); }
To my surprise I don't see my Log message but I still get the following error:
09-25 10:53:32.147: E/SQLiteDatabase(7991): android.database.sqlite.SQLiteConstraintException: error code 19: constraint failed
Why doesn't it catch the Exception? Am I doing something wrong here? All tips are welcome!
The save() method looks as follows:
public final void save() { final SQLiteDatabase db = Cache.openDatabase(); final ContentValues values = new ContentValues(); for (Field field : mTableInfo.getFields()) { final String fieldName = mTableInfo.getColumnName(field); Class<?> fieldType = field.getType(); field.setAccessible(true); try { Object value = field.get(this); if (value != null) { final TypeSerializer typeSerializer = Cache.getParserForType(fieldType); if (typeSerializer != null) { // serialize data value = typeSerializer.serialize(value); // set new object type if (value != null) { fieldType = value.getClass(); // check that the serializer returned what it promised if (!fieldType.equals(typeSerializer.getSerializedType())) { Log.w(String.format("TypeSerializer returned wrong type: expected a %s but got a %s", typeSerializer.getSerializedType(), fieldType)); } } } } // TODO: Find a smarter way to do this? This if block is necessary because we // can't know the type until runtime. if (value == null) { values.putNull(fieldName); } else if (fieldType.equals(Byte.class) || fieldType.equals(byte.class)) { values.put(fieldName, (Byte) value); } else if (fieldType.equals(Short.class) || fieldType.equals(short.class)) { values.put(fieldName, (Short) value); } else if (fieldType.equals(Integer.class) || fieldType.equals(int.class)) { values.put(fieldName, (Integer) value); } else if (fieldType.equals(Long.class) || fieldType.equals(long.class)) { values.put(fieldName, (Long) value); } else if (fieldType.equals(Float.class) || fieldType.equals(float.class)) { values.put(fieldName, (Float) value); } else if (fieldType.equals(Double.class) || fieldType.equals(double.class)) { values.put(fieldName, (Double) value); } else if (fieldType.equals(Boolean.class) || fieldType.equals(boolean.class)) { values.put(fieldName, (Boolean) value); } else if (fieldType.equals(Character.class) || fieldType.equals(char.class)) { values.put(fieldName, value.toString()); } else if (fieldType.equals(String.class)) { values.put(fieldName, value.toString()); } else if (fieldType.equals(Byte[].class) || fieldType.equals(byte[].class)) { values.put(fieldName, (byte[]) value); } else if (ReflectionUtils.isModel(fieldType)) { values.put(fieldName, ((Model) value).getId()); } else if (ReflectionUtils.isSubclassOf(fieldType, Enum.class)) { values.put(fieldName, ((Enum<?>) value).name()); } } catch (IllegalArgumentException e) { Log.e(e.getClass().getName(), e); } catch (IllegalAccessException e) { Log.e(e.getClass().getName(), e); } } if (mId == null) { mId = db.insert(mTableInfo.getTableName(), null, values); } else { db.update(mTableInfo.getTableName(), values, "Id=" + mId, null); } Cache.getContext().getContentResolver() .notifyChange(ContentProvider.createUri(mTableInfo.getType(), mId), null); }