[转]Java反射例子

package com.lion.util;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
/**
 *
 * @author liyongyao
 *
 */
public class GetClassInfo {
    /**
     * 获得属性名
     *
     * @param object
     * @return
     */
    public static ArrayList<String> ComponentsName(Object object) {
        Field[] fields = object.getClass().getDeclaredFields();
        ArrayList<String> filedName = new ArrayList<String>();
        for (int i = 0; i < fields.length; i++) {
            try {
                String varName = fields[i].getName();
                boolean accessFlag = fields[i].isAccessible();
                fields[i].setAccessible(true);
                filedName.add(varName);
                fields[i].setAccessible(accessFlag);
            } catch (SecurityException e) {
                e.printStackTrace();
            } catch (IllegalArgumentException e) {
                e.printStackTrace();
            }
        }
        return filedName;
    }
    /**
     * 获取键值对
     *
     * @param object
     * @return
     */
    public static Map<String, Object> ComponentsNameAndValue(Object object) {
        Field[] fields = object.getClass().getDeclaredFields();
        Map<String, Object> nameAndValue = new HashMap<String, Object>();
        ArrayList<String> filedName = new ArrayList<String>();
        ArrayList<Object> filedValue = new ArrayList<Object>();
        for (int i = 0; i < fields.length; i++) {
            try {
                boolean accessFlag = fields[i].isAccessible();
                fields[i].setAccessible(true);
                String varName = fields[i].getName();
                Object varValue = fields[i].get(object);
                filedName.add(varName);
                filedValue.add(varValue);
                fields[i].setAccessible(accessFlag);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        nameAndValue.put("value", filedValue);
        nameAndValue.put("key", filedName);
        return nameAndValue;
    }
    /**
     * 获取键值对打印到控制台
     *
     * @param object
     * @return
     */
    public static void printClassInfo(Object object) {
        Field[] fields = object.getClass().getDeclaredFields();
        for (int i = 0; i < fields.length; i++) {
            try {
                boolean accessFlag = fields[i].isAccessible();
                fields[i].setAccessible(true);
                String varName = fields[i].getName();
                Object varValue = fields[i].get(object);
                System.out.println(varName + "=" + varValue);
                fields[i].setAccessible(accessFlag);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    /**
     * 根据属性名称查找对象中的相应值
     *
     * @param name
     *            属性名
     * @param object
     *            要查找的对象
     * @return Object 返回属性对应的值
     */
    public static Object getValueByName(String name, Object object) {
        try {
            Field f = object.getClass().getDeclaredField(name);
            boolean accessFlag = f.isAccessible();
            f.setAccessible(true);
            Object o = f.get(object);
            f.setAccessible(accessFlag);
            return o;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    public static Object setValueByName(String name, Object value, Object object) {
        try {
            Field f = object.getClass().getDeclaredField(name);
            boolean accessFlag = f.isAccessible();// 获得原始权限
            f.setAccessible(true);// 权限设置为可访问
            f.set(object, value);
            f.setAccessible(accessFlag);// 还原权限
            return object;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}