/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package hivemall.utils.lang;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
public final class PrivilegedAccessor {
public static Field getField(final Class<?> clazz, final String fieldName) {
try {
return getField(clazz, fieldName, true);
} catch (NoSuchFieldException e) {
throw new Error(e);
}
}
public static Field getField(final Class<?> clazz, final String fieldName,
final boolean accessible) throws NoSuchFieldException {
final Field field;
try {
field = AccessController.<Field>doPrivileged(new PrivilegedExceptionAction<Field>() {
public Field run() throws NoSuchFieldException {
Field f = clazz.getDeclaredField(fieldName);
f.setAccessible(accessible);
return f;
}
});
} catch (PrivilegedActionException e) {
throw new AssertionError(e.getCause());
}
return field;
}
public static void setField(final Object obj, final Class<?> clazz, final String fieldName,
final Object value) {
final Field field;
try {
field = AccessController.<Field>doPrivileged(new PrivilegedExceptionAction<Field>() {
public Field run() throws NoSuchFieldException {
Field f = clazz.getDeclaredField(fieldName);
f.setAccessible(true);
return f;
}
});
} catch (PrivilegedActionException e) {
throw new AssertionError(e.getCause());
}
try {
field.set(obj, value);
} catch (IllegalArgumentException arge) {
throw new Error(arge);
} catch (IllegalAccessException acce) {
throw new Error(acce);
}
}
public static void setField(final Object obj, final Field field, final Object value) {
try {
field.set(obj, value);
} catch (IllegalArgumentException arge) {
throw new Error(arge);
} catch (IllegalAccessException acce) {
throw new Error(acce);
}
}
/**
* Return the named method with a method signature matching classTypes from the given class.
*/
public static Method getMethod(Class<?> thisClass, String methodName, Class<?>[] classTypes)
throws NoSuchMethodException {
if (thisClass == null) {
throw new NoSuchMethodException("Class is not specified for method " + methodName + ".");
}
try {
return thisClass.getDeclaredMethod(methodName, classTypes);
} catch (NoSuchMethodException e) {
return getMethod(thisClass.getSuperclass(), methodName, classTypes);
}
}
public static Method getMethod(Object instance, String methodName, Class<?>[] classTypes)
throws NoSuchMethodException {
Method accessMethod = getMethod(instance.getClass(), methodName, classTypes);
accessMethod.setAccessible(true);
return accessMethod;
}
/**
* Gets the value of the named field and returns it as an object.
*
* @param instance the object instance
* @param fieldName the name of the field
* @return an object representing the value of the field
*/
public static Object getValue(Object instance, String fieldName) throws IllegalAccessException,
NoSuchFieldException {
Field field = getField(instance.getClass(), fieldName, true);
return field.get(instance);
}
/**
* Calls a method on the given object instance with the given argument.
*
* @param instance the object instance
* @param methodName the name of the method to invoke
* @param arg the argument to pass to the method
* @see PrivilegedAccessor#invokeMethod(Object,String,Object[])
*/
public static Object invokeMethod(Object instance, String methodName, Object arg)
throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
Object[] args = new Object[1];
args[0] = arg;
return invokeMethod(instance, methodName, args);
}
/**
* Calls a method on the given object instance with the given arguments.
*
* @param instance the object instance
* @param methodName the name of the method to invoke
* @param args an array of objects to pass as arguments
* @see PrivilegedAccessor#invokeMethod(Object,String,Object)
*/
public static Object invokeMethod(Object instance, String methodName, Object... args)
throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
Class<?>[] classTypes = null;
if (args != null) {
classTypes = new Class[args.length];
for (int i = 0; i < args.length; i++) {
if (args[i] != null)
classTypes[i] = args[i].getClass();
}
}
return getMethod(instance, methodName, classTypes).invoke(instance, args);
}
/**
* Calls a static method in the given class with the given argument.
*/
public static Object invokeStaticMethod(String className, String methodName, Object arg)
throws SecurityException, IllegalArgumentException, NoSuchMethodException,
ClassNotFoundException, IllegalAccessException, InvocationTargetException {
Object[] args = new Object[1];
args[0] = arg;
return invokeStaticMethod(className, methodName, args);
}
/**
* Calls a static method in the given class with the given arguments.
*/
public static Object invokeStaticMethod(String className, String methodName, Object... args)
throws SecurityException, NoSuchMethodException, ClassNotFoundException,
IllegalArgumentException, IllegalAccessException, InvocationTargetException {
Class<?> primeClass = Class.forName(className);
Class<?>[] classTypes = null;
if (args != null) {
classTypes = new Class[args.length];
for (int i = 0; i < args.length; i++) {
if (args[i] != null)
classTypes[i] = args[i].getClass();
}
}
Method method = primeClass.getDeclaredMethod(methodName, classTypes);
method.setAccessible(true);
return method.invoke(method, args);
}
/**
* Calls a static method with the given class and the given arguments. use this method when the
* specified arguments includes null object.
*/
public static Object invokeStaticMethod(String className, String methodName,
Class<?>[] classTypes, Object... objects) throws ClassNotFoundException,
SecurityException, NoSuchMethodException, IllegalArgumentException,
IllegalAccessException, InvocationTargetException {
Class<?> primeClass = Class.forName(className);
Method method = primeClass.getDeclaredMethod(methodName, classTypes);
method.setAccessible(true);
return method.invoke(method, objects);
}
}