Java Reflection Field Value Set setFieldValue(Object target, Class targetClass, String fieldName, Object value)

Description

set Field Value

License

Apache License

Declaration

private static void setFieldValue(Object target, Class<? extends Object> targetClass, String fieldName,
            Object value) throws IllegalAccessException 

Method Source Code

//package com.java2s;
/*/*w w  w .  jav a  2  s . c  om*/
 * @(#)ReflectionUtils.java     7 Nov 2008
 * 
 * Copyright ? 2009 Andrew Phillips.
 *
 * ====================================================================
 * Licensed 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.
 * ====================================================================
 */

import java.lang.reflect.Field;

public class Main {
    private static void setFieldValue(Object target, Class<? extends Object> targetClass, String fieldName,
            Object value) throws IllegalAccessException {

        try {
            Field field = getAccessibleField((target != null) ? target.getClass() : targetClass, fieldName);
            field.set(target, value);
        } catch (Exception exception) {
            boolean instanceFieldRequested = (target != null);
            throw new IllegalAccessException(String.format("Unable to set field '%s' on %s '%s' due to %s: %s",
                    fieldName, instanceFieldRequested ? "object" : "class",
                    instanceFieldRequested ? target : targetClass.getName(), exception.getClass().getSimpleName(),
                    exception.getMessage()));
        }

    }

    private static Field getAccessibleField(Class<? extends Object> targetClass, String fieldName)
            throws SecurityException, NoSuchFieldException {
        Class<?> currentClass = targetClass;
        Field field = null;

        // the loop will be exited if the current class is Object.class and nothing is found
        do {

            try {
                field = currentClass.getDeclaredField(fieldName);
            } catch (NoSuchFieldException exception) {

                // try the superclass
                currentClass = currentClass.getSuperclass();
            }

        } while ((field == null) && (currentClass != null));

        if (field == null) {
            throw new NoSuchFieldException(fieldName);
        }

        if (!field.isAccessible()) {
            field.setAccessible(true);
        }

        return field;
    }
}

Related

1. setFieldValue(Object object, String name, Object value)
2. setFieldValue(Object object, String name, Object value)
3. setFieldValue(Object objectInstance, String fieldName, Object valueToSet)
4. setFieldValue(Object pojo, Field field, Object value)
5. setFieldValue(Object receiver, String fieldName, Object value)
6. setFieldValue(Object target, Field field, Object newValue)
7. setFieldValue(Object target, Field field, Object value)
8. setFieldValue(Object target, Object mock, final Field field)
9. setFieldValue(Object target, String field, Object value)