Java Reflection Method Getter Invoke invokeGetter(Object entity, String propertyName)

Description

Returns the value of a property on an entity based on its name.

License

Open Source License

Parameter

Parameter	Description
entity	The entity.
propertyName	The property name.

Exception

Parameter	Description
Exception	an exception

Return

The value of a property for an entity.

Declaration

public static Object invokeGetter(Object entity, String propertyName) throws Exception 

Method Source Code

//package com.java2s;
/**//w  ww  .j av a2 s  .  c  o  m
 * Copyright 2005-2014 Restlet
 * 
 * The contents of this file are subject to the terms of one of the following
 * open source licenses: Apache 2.0 or or EPL 1.0 (the "Licenses"). You can
 * select the license that you prefer but you may not use this file except in
 * compliance with one of these Licenses.
 * 
 * You can obtain a copy of the Apache 2.0 license at
 * http://www.opensource.org/licenses/apache-2.0
 * 
 * You can obtain a copy of the EPL 1.0 license at
 * http://www.opensource.org/licenses/eclipse-1.0
 * 
 * See the Licenses for the specific language governing permissions and
 * limitations under the Licenses.
 * 
 * Alternatively, you can obtain a royalty free commercial license with less
 * limitations, transferable or non-transferable, directly at
 * http://restlet.com/products/restlet-framework
 * 
 * Restlet is a registered trademark of Restlet S.A.S.
 */

import java.lang.reflect.Method;

public class Main {
    /**
     * Returns the value of a property on an entity based on its name.
     * 
     * @param entity
     *            The entity.
     * @param propertyName
     *            The property name.
     * @return The value of a property for an entity.
     * @throws Exception
     */
    public static Object invokeGetter(Object entity, String propertyName) throws Exception {
        Object result = null;

        if (propertyName != null && entity != null) {
            propertyName = propertyName.replaceAll("/", ".");
            Object o = entity;
            String pty = propertyName;
            int index = propertyName.indexOf(".");
            if (index != -1) {
                o = invokeGetter(entity, propertyName.substring(0, index));
                pty = propertyName.substring(index + 1);

                result = invokeGetter(o, pty);
            } else {
                String getterName = null;
                char firstLetter = propertyName.charAt(0);
                if (Character.isLowerCase(firstLetter)) {
                    getterName = "get" + Character.toUpperCase(firstLetter) + pty.substring(1);
                } else {
                    getterName = "get" + pty;
                }

                Method getter = null;
                Method method;
                for (int i = 0; (getter == null) && (i < entity.getClass().getDeclaredMethods().length); i++) {
                    method = entity.getClass().getDeclaredMethods()[i];

                    if (method.getName().equals(getterName)) {
                        getter = method;
                    }
                }

                if (getter != null) {
                    result = getter.invoke(o);
                }
            }
        }

        return result;
    }
}

Related

1. invokeGetMethod(Object obj, String getterName)
2. invokeGetter(Method getter, Object object)
3. invokeGetter(Object bean, Method getter)
4. invokeGetter(Object getterOwner, Method method)
5. invokeGetter(Object o, String name, boolean forceAccess)
6. invokeGetter(Object obj, String methodName)
7. invokeGetter(Object obj, String methodName, int defaultValue)