com.darwinsys.util.ObjectMerge Maven / Gradle / Ivy
package com.darwinsys.util;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
public class ObjectMerge {
public static Object merge(Object left, Object right) throws Exception {
Object merge = null;
Class c = left.getClass();
if (left.getClass() != right.getClass()) {
throw new IllegalArgumentException(left + " class != " + right);
}
merge = c.newInstance();
Field[] fields = c.getDeclaredFields();
for (Field f : fields) {
int mod = f.getModifiers();
if (Modifier.isFinal(mod) ||
Modifier.isStatic(mod))
continue; // can not merge final or static
f.setAccessible(true);
Object l = f.get(left);
Object r = f.get(right);
if (l == null && r == null) {
continue; // leave it null
}
if (l == null) {
f.set(merge, r); // go w/ right's val
} else if (r == null) {
f.set(merge, l); // go w/ left's
} else if (l.equals(r)) {
f.set(merge, l);
} else {
// they differ, leave it null
}
}
return merge;
}
}