java 类加载-初始化顺序

代码：

package com.lczyfz.istep.modules.test.service;

class Root {

static

{

System.out.println("Root的静态初始化块");

}

{

System.out.println("Root的普通初始化块");

}

public Root(){

System.out.println("Root的无参数构造器");

}

}

class Mid extends Root {

static

{

System.out.println("Mid的静态初始化块");

}

{

System.out.println("Mid的普通初始化块");

}

public Mid(){

System.out.println("Mid的无参数构造器");

}

public Mid(String msg){

this();

System.out.println("Mid的带参数构造器，其参数值：" + msg);

}

}

class Leaf extends Mid{

static {

System.out.println("Leaf的静态初始化块");

}

{

System.out.println("Leaf的普通初始化块");

}

public Leaf(){

super("疯狂java讲义");

System.out.println("执行Leaf的构造器");

}

}

public class Test{

public static void main(String[] args){

new Leaf();

new Leaf();

}

}

答案：

Root的静态初始化块

Mid的静态初始化块

Leaf的静态初始化块

Root的普通初始化块

Root的无参数构造器

Mid的普通初始化块

Mid的无参数构造器

Mid的带参数构造器，其参数值：疯狂java讲义

Leaf的普通初始化块

执行Leaf的构造器

Root的普通初始化块

Root的无参数构造器

Mid的普通初始化块

Mid的无参数构造器

Mid的带参数构造器，其参数值：疯狂java讲义

Leaf的普通初始化块

执行Leaf的构造器

============================================================

静态初始化块和声明静态Field时所指定的初始值都是该类的初始化代码，它们的执行顺序与源程序中的排列顺序相同。

代码：

package com.lczyfz.istep.modules.test.service;

/**

* Created by hpp on 2017/4/5.

*/

class Base{

static {

System.out.println("Base static");

}

public Base(){

System.out.println("Base init");

}

}

public class Test1 extends Base{

String m = "";

static String n;

static {

System.out.println("A static");

}

public Test1(String mValue,String nValue){

m = mValue;

n = nValue;

}

public void print(){

System.out.println(m + " " + n);

}

public static void main(String[] args){

Test1 a1 = new Test1("M1","N1");

Test1 a2 = new Test1("M2","N2");

a1.print();

a2.print();

}

答案：

Base static

A static

Base init

Base init

M1 N2

M2 N2

public static void main(String[] args){

Test1 a1 = new Test1("M1","N1");

a1.print();

Test1 a2 = new Test1("M2","N2");

a2.print();

}

答案：

Base static

A static

Base init

M1 N1

Base init

M2 N2

}