Java Reflection Field Set setField(Field field, Object target, Object value)

Description

Set a field

License

Open Source License

Parameter

Parameter	Description
field	the field
target	the target
value	the value

Exception

Parameter	Description
Throwable	for any error

Return

null

Declaration

public static Object setField(Field field, Object target, Object value) throws Throwable 

Method Source Code

//package com.java2s;
/*/*from ww w  .j a va 2s . co m*/
* JBoss, Home of Professional Open Source
* Copyright 2006, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;

import java.util.ArrayList;

import java.util.List;

public class Main {
    /**
     * Set a field
     * 
     * @param field the field
     * @param target the target
     * @param value the value
     * @return null
     * @throws Throwable for any error
     */
    public static Object setField(Field field, Object target, Object value) throws Throwable {
        if (field == null)
            throw new IllegalArgumentException("Null field");

        try {
            field.set(target, value);
            return null;
        } catch (Throwable t) {
            throw handleErrors("set", field, target, value, t);
        }
    }

    /**
     * Handle errors
     * 
     * @param context the context
     * @param target the target
     * @param parameters the parameters
     * @param arguments the arguments
     * @param t the error
     * @return never
     * @throws Throwable always
     */
    public static Throwable handleErrors(String context, Object target, Class<?>[] parameters, Object[] arguments,
            Throwable t) throws Throwable {
        if (t instanceof IllegalArgumentException) {
            if (target == null)
                throw new IllegalArgumentException("Null target for " + context);

            List<String> expected = new ArrayList<String>();
            if (parameters != null) {
                for (Class<?> parameter : parameters)
                    expected.add(parameter.getName());
            }
            List<String> actual = new ArrayList<String>();
            if (arguments != null) {
                for (Object argument : arguments) {
                    if (argument == null)
                        actual.add(null);
                    else
                        actual.add(argument.getClass().getName());
                }
            }
            throw new IllegalArgumentException("Wrong arguments. " + context + " for target " + target
                    + " expected=" + expected + " actual=" + actual);
        } else if (t instanceof InvocationTargetException) {
            throw ((InvocationTargetException) t).getTargetException();
        }
        throw t;
    }

    /**
     * Handle errors
     * 
     * @param context the context
     * @param field the field
     * @param target the target
     * @param value the value
     * @param t the error
     * @return never
     * @throws Throwable always
     */
    public static Throwable handleErrors(String context, Field field, Object target, Object value, Throwable t)
            throws Throwable {
        if (t instanceof IllegalArgumentException) {
            Class<?> clazz = field.getDeclaringClass();
            if (clazz.isInstance(target) == false)
                throw new IllegalArgumentException(
                        "Wrong target. " + target.getClass().getName() + " is not a " + clazz.getName());

            String valueType = null;
            if (value != null)
                valueType = value.getClass().getName();
            throw new IllegalArgumentException(
                    "Error invoking field " + context + " for target " + target + " field " + field.getName()
                            + " expected=" + field.getType().getName() + " actual=" + valueType);
        }
        throw t;
    }
}

Related

1. setField(Field field, Object classWithField, Object value)
2. setField(Field field, Object instance, Object value)
3. setField(Field field, Object obj, String value)
4. setField(Field field, Object objToSet, Object value)
5. setField(Field field, Object target, Object value)
6. setField(Field field, Object target, Object value)
7. setField(Field field, Object target, Object value)
8. setField(Field field, Object target, Object value)
9. setField(Field field, Object target, Object value)