匿名构造方法的使用以及比较对象的问题

package com.yonge.objectEquals;

/**
 * 目的：1、测试匿名构造方法的使用及作用域   2、对象的比较
 * @author wb-gaoy
 * @version $Id: Test.java,v 0.1 2012-1-10 下午12:04:42 wb-gaoy Exp $
 */
public class Test {

    private String str;

    /** 默认构造方法 */
    public Test() {
        System.out.println("默认构造方法被调用！！");
    }

    /** 带两个String参数的构造方法 */
    public Test(String arg0, String arg1) {
        System.out.println("带参数的构造方法！");
        this.str = arg0 + arg1;
        if (str == (arg0 + arg1)) {
            System.out.println("str[" + this.str + "]与arg0+arg1[" + arg0 + arg1 + "]相等！！");
        } else {
            System.out.println("str[" + this.str + "]与arg0+arg1[" + arg0 + arg1 + "]不相等！！");
        }
    }

    /** 匿名构造方法：每次实例化对象的时候，首先会调用此块 */
    {
        System.out.println("匿名构造方法被调用！");
    }

    /**
     * @param args
     */
    public static void main(String[] args) {

        Test test = new Test();
        Test test1 = new Test("1", "");
        String arg0 = "1", arg1 = "1";

        if (arg0 == arg1) {
            System.out.println("arg0[" + arg0 + "]与arg1[" + arg1 + "]对象相等！！");
        } else {
            System.out.println("arg0[" + arg0 + "]与arg1[" + arg1 + "]对象相等！！");
        }

        //给arg0重新赋值
        arg0 = "1" + "";
        System.out.println("给arg0重新赋值为:" + arg0);
        if (arg0 == arg1) {
            System.out.println("arg0[" + arg0 + "]与arg1[" + arg1 + "]对象相等！！");
        } else {
            System.out.println("arg0[" + arg0 + "]与arg1[" + arg1 + "]对象相等！！");
        }
        
        if ("1" + "" == arg1) {
            System.out.println("arg0[\"1\" + \"\"]与arg1[" + arg1 + "]对象相等！！");
        } else {
            System.out.println("arg0[" + arg0 + "]与arg1[" + arg1 + "]对象相等！！");
        }

        //给arg0重新赋值
        arg0 = new String("1");//改成arg0 = new String("2")试试
        System.out.println("给arg0第二次重新赋值为:" + arg0);
        if (arg0 == arg1) {
            System.out.println("arg0[" + arg0 + "]与arg1[" + arg1 + "]对象相等！！");
        } else {
            System.out.println("arg0[" + arg0 + "]与arg1[" + arg1 + "]对象相等！！");
        }

        if (new String("1") == "1") {
            System.out.println("对象相等");
        } else {
            System.out.println("对象不相等");
        }
    }

}