Java Reflection Field Set setFieldContent(final Object obj, final String name, final Object value)

Description

This method sets the contents of an object variable.

License

Open Source License

Parameter

Parameter	Description
obj	Object.
name	Variable name.
value	Value to set.

Exception

Parameter	Description
NoSuchFieldException	Variable of given name was not found.

Declaration

public static void setFieldContent(final Object obj, final String name, final Object value)
        throws NoSuchFieldException 

Method Source Code

//package com.java2s;
/* This file is part of the project "Hilbert II" - http://www.qedeq.org
 *
 * Copyright 2000-2013,  Michael Meyling <mime@qedeq.org>.
 *
 * "Hilbert II" is free software; you can redistribute
 * it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *//*from  www.  j  a  va  2s  .  c  om*/

import java.lang.reflect.Field;

public class Main {
    /**
     * This method sets the contents of an object variable. The class hierarchy is recursively
     * searched to find such a field (even if it is private).
     *
     * @param   obj     Object.
     * @param   name    Variable name.
     * @param   value   Value to set.
     * @throws  NoSuchFieldException    Variable of given name was not found.
     */
    public static void setFieldContent(final Object obj, final String name, final Object value)
            throws NoSuchFieldException {
        final Field field = getField(obj, name);
        try {
            field.set(obj, value);
        } catch (IllegalArgumentException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Get field of given name in given object. The class hierarchy is recursively searched
     * to find such a field (even if it is private).
     *
     * @param   obj     Object to work on.
     * @param   name    Search this field.
     * @return  Found field.
     * @throws  NoSuchFieldException    Field with name <code>name</code> was not found.
     */
    public static Field getField(final Object obj, final String name) throws NoSuchFieldException {
        Field field = null;
        try {
            Class cl = obj.getClass();
            while (!Object.class.equals(cl)) {
                try {
                    field = cl.getDeclaredField(name);
                    break;
                } catch (NoSuchFieldException ex) {
                    cl = cl.getSuperclass();
                }
            }
            if (field == null) {
                throw (new NoSuchFieldException(name + " within " + obj.getClass()));
            }
            field.setAccessible(true);
        } catch (SecurityException e) {
            throw new RuntimeException(e);
        }
        return field;
    }
}

Related

1. setField(String name, Object target, Object value)
2. setField(T object, Field field, ResourceBundle bundle)
3. setFieldAccessible(Class clazz, String... names)
4. setFieldAccessible(Field field)
5. setFieldBySomeMethod(List setMethods, Object object, Object value)
6. setFieldEditable(Class clazz, String fieldName)
7. setFieldForAnnotation(Object target, Class annotation, Object value)
8. setFieldHelper(Object o, String name, Object v)
9. setFieldIfExists(final Object instance, final String fieldName, final Object value)