set Bean - Java Reflection

Java examples for Reflection:Field Set

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Description

set Bean

Demo Code

/**/*from w  w  w .ja  v a 2s.c o  m*/
 * Copyright 2008-2009 the original author or authors.
 *
 * 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. 
 */
//package com.java2s;
import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;

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

public class Main {


    public static void setBean(Object obj, String beanPath, Object value)
            throws IllegalStateException {
        try {
            if (beanPath.indexOf('.') > -1) {
                String name = beanPath.substring(0, beanPath.indexOf('.'));
                String path = beanPath.substring(beanPath.indexOf('.') + 1);
                Field field = findField(obj, name);
                field.setAccessible(true);
                Object child = field.get(obj);
                if (child == null) {
                    throw new IllegalStateException(
                            "Choked on a null field '" + name + "' on "
                                    + obj.getClass().getName());
                }
                setBean(child, path, value);
            } else {
                setField(obj, beanPath, value);
            }
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    public static Field findField(Object obj, String beanPath) {
        try {
            if (beanPath.indexOf('.') > -1) {
                String name = beanPath.substring(0, beanPath.indexOf('.'));
                String path = beanPath.substring(beanPath.indexOf('.') + 1);
                Field field = obj.getClass().getDeclaredField(name);
                field.setAccessible(true);
                return findField(field.get(obj), path);
            } else if (obj == null) {
                return null;
            } else {
                return obj.getClass().getDeclaredField(beanPath);
            }
        } catch (NoSuchFieldException e) {
            return null;
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    public static void setField(Object parent, String fieldName,
            Object value) {
        try {
            Method method = findSetter(parent, fieldName);
            if (method != null) {
                method.setAccessible(true);
                method.invoke(parent, new Object[] { value });
            } else {
                Field field = parent.getClass().getDeclaredField(fieldName);
                field.setAccessible(true);
                field.set(parent, value);
            }
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        } catch (InvocationTargetException e) {
            throw new RuntimeException(e);
        } catch (NoSuchFieldException e) {
            throw new IllegalArgumentException("Field '" + fieldName
                    + "' was not found on " + parent.getClass().getName());
        }
    }

    private static Method findSetter(Object parent, String fieldName) {
        try {
            PropertyDescriptor descriptor = new PropertyDescriptor(
                    fieldName, parent.getClass());
            return descriptor.getWriteMethod();
        } catch (IntrospectionException e) {
            return null;
        }
    }
}

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