JAVA基础

[时光清浅]

public class Reluctant {

	private Reluctant instance = new Reluctant();

	public Reluctant() throws Exception {
		throw new Exception("-->Reluctant Exception");
	}

	public static void main(String[] args) {
		try {
			Reluctant r = new Reluctant(); //调用构造方法之后，为啥初始化instance？
			System.out.println("-->main");
		} catch (Exception e) {
			System.out.println("-->main Exception");
		}
	}
}

我DEBUG了下，发现在构造方法和instance对象初始化之间，是死循环。
1.对象的初始化顺序？
2.为什么这里产生了递归调用？

请大家讲下，谢谢！

[亲努力啊]

Reluctant r = new Reluctant(); r这个对象定义了instance 变量 并对其进行了初使化

[七神之光]

Compiled from "TRRRR.java" public class test.TRRRR extends java.lang.Object{ public test.TRRRR() throws java.lang.Exception; Code: 0: aload_0 1: invokespecial #1; //Method java/lang/Object."<init>":()V 4: aload_0 5: new #2; //class test/TRRRR 8: dup 9: invokespecial #3; //Method "<init>":()V 12: putfield #4; //Field instance:Ltest/TRRRR; 15: new #5; //class java/lang/Exception 18: dup 19: ldc #6; //String -->Reluctant Exception 21: invokespecial #7; //Method java/lang/Exception."<init>":(Ljava/lang/St ring;)V 24: athrow 循环引用构造 看标号5

[teemai]

死循环构造。 你main里面new一个之后，初始化r的时候，r对象里面的成员instance又要初始化，instance new的时候又有成员instance..无限循环

[姜小白-]

private Reluctant instance = new Reluctant(); instance成为Reluctant类的一个属性，构造Reluctant 也会再调用new Reluctant()

[姜小白-]

引用 2 楼 fatg1988 的回复:

Compiled from "TRRRR.java" public class test.TRRRR extends java.lang.Object{ public test.TRRRR() throws java.lang.Exception; Code: 0: aload_0 1: invokespecial #1; //Method java/lang/Object."<init>":()V 4: aload_0 5: new #2; //class test/TRRRR 8: dup 9: invokespecial #3; //Method "<init>":()V 12: putfield #4; //Field instance:Ltest/TRRRR; 15: new #5; //class java/lang/Exception 18: dup 19: ldc #6; //String -->Reluctant Exception 21: invokespecial #7; //Method java/lang/Exception."<init>":(Ljava/lang/St ring;)V 24: athrow 循环引用构造 看标号5

大牛，这个怎么出来的，求方法技巧，想学习下

[___________小P]

我就过来看看技术

[qianfu111]

没见这样玩过呀，3楼讲的不错，楼主这是要想实现单例类吗？

[七神之光]

引用 5 楼 magi1201 的回复:

[quote=引用 2 楼 fatg1988 的回复:] Compiled from "TRRRR.java" public class test.TRRRR extends java.lang.Object{ public test.TRRRR() throws java.lang.Exception; Code: 0: aload_0 1: invokespecial #1; //Method java/lang/Object."<init>":()V 4: aload_0 5: new #2; //class test/TRRRR 8: dup 9: invokespecial #3; //Method "<init>":()V 12: putfield #4; //Field instance:Ltest/TRRRR; 15: new #5; //class java/lang/Exception 18: dup 19: ldc #6; //String -->Reluctant Exception 21: invokespecial #7; //Method java/lang/Exception."<init>":(Ljava/lang/St ring;)V 24: athrow 循环引用构造 看标号5

大牛，这个怎么出来的，求方法技巧，想学习下[/quote]javap -c xx.class

[姜小白-]

引用 8 楼 fatg1988 的回复:

javap -c xx.class

灰常感谢

[JessonLv]

引用 3 楼 huxiweng 的回复:

死循环构造。 你main里面new一个之后，初始化r的时候，r对象里面的成员instance又要初始化，instance new的时候又有成员instance..无限循环

说的对！