Converting Integer to Long
casting, java, reflection
Solution
No, you can't cast `Integer` to `Long`, even though you can convert from `int` to `long`. For an individual value which is known to be a number and you want to get the long value, you could use:
Number tmp = getValueByReflection(inv.var1(), classUnderTest, runtimeInstance);
Long value1 = tmp.longValue();
For arrays, it will be trickier...
Problem
I need to get the value of a field using reflection. It so happens that I am not always sure what the datatype of the field is. For that, and to avoid some code duplication I have created the following method: ``` @SuppressWarnings("unchecked") private static <T> T getValueByReflection(VarInfo var, Class<?> classUnderTest, Object runtimeInstance) throws Throwable { Field f = classUnderTest.getDeclaredField(processFieldName(var)); f.setAccessible(true); T value = (T) f.get(runtimeInstance); return value; } ``` And use this method like: ``` Long value1 = getValueByReflection(inv.var1(), classUnderTest, runtimeInstance); ``` or ``` Double[] value2 = getValueByReflection(inv.var2(), classUnderTest, runtimeInstance); ``` The problem is that I can't seem to cast `Integer` to `Long`: ``` java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Long ``` Is there a better way to achieve this? I am using Java 1.6.