返回给定bean中指定属性的值

/**

 * JLibs: Common Utilities for Java

 * Copyright (C) 2009  Santhosh Kumar T <santhosh.tekuri@gmail.com>

 *

 * This library 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 library 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.

 *//**时代Java - N o w  J a v a . c o m**/

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.util.Locale;


public class Main{

    public static void main(String[] argv) throws Exception{

        Object bean = "nowjava.com";

        String property = "nowjava.com";

        System.out.println(getProperty(bean,property));

    }

    /** prefix used by non-boolean getter methods */

    public static final String GET = "get";

    /** prefix used by boolean getter methods */

    public static final String IS = "is";

    /**

     * Returns the value of the specified <code>property</code> in given <code>bean</code>

     *

     * @param bean      bean object

     * @param property  property name whose value needs to be returned

     *

     * @return  value of the property.

     *

     * @throws InvocationTargetException if method invocation fails

     * @throws NullPointerException if <code>property</code> is not found in <code>bean</code>

     */

    @SuppressWarnings({ "unchecked" })

    public static <T> T getProperty(Object bean, String property)

            throws InvocationTargetException {
            /**来自 
             n o w j a v a . c o m - 时代Java**/

        try {

            return (T) getGetterMethod(bean.getClass(), property).invoke(

                    bean);

        } catch (IllegalAccessException ex) {

            throw new ImpossibleException(ex); // because getter method is public

        }

    }

    /**

     * Returns getter method for <code>property</code> in specified <code>beanClass</code>

     *

     * @param beanClass bean class

     * @param property  name of the property

     *

     * @return getter method. null if <code>property</code> is not found

     *

     * @see #getGetterMethod(Class, String, Class)

     */

    public static Method getGetterMethod(Class<?> beanClass, String property) {

        try {

            return beanClass.getMethod(GET + getMethodSuffix(property));

        } catch (NoSuchMethodException ex1) {

            try {

                return beanClass.getMethod(IS + getMethodSuffix(property));

            } catch (NoSuchMethodException ex2) {

                return null;

            }

        }

    }

    /**

     * Returns getter method for <code>property</code> in specified <code>beanClass</code>

     *

     * @param beanClass bean class

     * @param property  name of the property

     * @param propertyType type of the property. This is used to compute getter method name.

     *

     * @return getter method. null if <code>property</code> is not found

     *

     * @see #getGetterMethod(Class, String)

     */

    public static Method getGetterMethod(Class<?> beanClass,

            String property, Class propertyType) {

        try {

            try {

                if (propertyType == boolean.class)

                    return beanClass.getMethod(IS

                            + getMethodSuffix(property));

            } catch (NoSuchMethodException ignore) {

                // ignore

            }

            return beanClass.getMethod(GET + getMethodSuffix(property));

        } catch (NoSuchMethodException ex) {

            return null;

        }

    }

    public static String getMethodSuffix(String property) {

        switch (property.length()) {

        case 0:

            throw new IllegalArgumentException("invalid property name: "

                    + property);

        case 1:

            return property.toUpperCase(Locale.ENGLISH);

        default:

            char char0 = property.charAt(0);

            boolean upper0 =