org.apache.cayenne.reflect.CallbackOnEntity Maven / Gradle / Ivy
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package org.apache.cayenne.reflect;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.util.Util;
/**
* Defines a generic callback operation executed via reflection on a persistent object.
* Note that the method must be declared in the class itself. Callback will not look up
* the class hierarchy.
*
* @since 3.0
*/
class CallbackOnEntity extends AbstractCallback {
private Method callbackMethod;
CallbackOnEntity(Class objectClass, String methodName)
throws IllegalArgumentException {
this.callbackMethod = findMethod(objectClass, methodName);
}
@Override
public void performCallback(Object entity) {
try {
callbackMethod.invoke(entity, (Object[]) null);
}
catch (Exception e) {
throw new CayenneRuntimeException("Error invoking entity callback method "
+ callbackMethod.getName(), e);
}
}
@Override
public String toString() {
return "callback-entity: "
+ callbackMethod.getDeclaringClass().getName()
+ "."
+ callbackMethod.getName();
}
private Method findMethod(Class objectClass, String methodName)
throws IllegalArgumentException {
Method[] methods = objectClass.getDeclaredMethods();
for (Method method : methods) {
if (methodName.equals(method.getName())) {
// must be non-static, void, with no args
// JPA spec also requires it to be non-final, but we don't care
int modifiers = method.getModifiers();
if (!Modifier.isStatic(modifiers)
&& Void.TYPE.isAssignableFrom(method.getReturnType())
&& method.getParameterTypes().length == 0) {
if (!Util.isAccessible(method)) {
method.setAccessible(true);
}
return method;
}
}
}
throw new IllegalArgumentException("Class "
+ objectClass.getName()
+ " has no valid callback method '"
+ methodName
+ "'");
}
}