尝试获取静态字段的初始值

/**
来 自 NowJava.com - 时  代  Java
**/

/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you 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.nowjava;

import java.lang.reflect.Array;

import java.lang.reflect.Field;


public class Main {

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

        Class clazz = String.class;

        String fieldName = "nowjava.com";

        System.out.println(java.util.Arrays

                .toString(getInitializationExpression(clazz, fieldName)));

    }


    public static ClassLoader classLoader;


    /**

     * Try to get the initial value of a static field

     * @param clazz     The class.

     * @param fieldName The name of the field.

     * @return The initial value or null.

     */

    public static String[] getInitializationExpression(Class<?> clazz,// 来自 时 代      J a v a   公   众 号 - nowjava.com

            String fieldName) {

        try {

            final Field field = clazz.getDeclaredField(fieldName);

            field.setAccessible(true);

            final Object value = field.get(null);

            if (value != null) {

                if (value.getClass().isArray()) {

                    final String[] values = new String[Array

                            .getLength(value)];

                    for (int i = 0; i < values.length; i++) {

                        values[i] = Array.get(value, i).toString();

                    }

                    return values;

                }

                return new String[] { value.toString() };

            }

            return null;

        } catch (NoClassDefFoundError e) {

            // ignore and just return null

        } catch (Exception e) {

            // ignore and just return null

        }

        return null;

    }


    /**

     * Get the compiled class.

     */