对象初始化语块执行顺序

对象初始化语块执行顺序:

static initialization block

new Employee1----------

instance field initialization

object initialization block
Employee(String name, double salary)

new Employee2----------
instance field initialization
object initialization block
Employee(String name, double salary)
Employee(double salary)

new Employee3----------
instance field initialization
object initialization block

Employee()

1676 xkfx 30000.0
1677 Employee #1677 60000.0
1678 0.0

Process finished with exit code 0

import java.util.Random;

/**
* Created by xkfx on 2016/12/14.
*  only 20
*/
public class Employee{
private static int nextId;

private int id;
private String name = test(); // instance field initialization
private double salary;

// static initialization block
static{
Random generator = new Random();
nextId = generator.nextInt(10000);
System.out.println("static initialization block");
}

// object initialization block
{
id = nextId ++;
System.out.println("object initialization block");
}

// three overloads constructors
public Employee(String name, double salary){
this.name = name;
this.salary =salary;
System.out.println("Employee(String name, double salary)");
}

public Employee(double salary){
// calls the Employee(String, double) constructor
this("Employee #" + nextId, salary);
System.out.println("Employee(double salary)");
}

// the default constructor
public Employee(){
// name initialized to "" --see above
// salary not explicitly set--initialized to 0
// id initialized in initialization block
System.out.println("Employee()");
}

public String getName(){
return this.name;
}

public double getSalary(){
return this.salary;
}

public int getId(){
return this.id;
}

private String test(){
System.out.println("----------instance field initialization");
return "";
}
}

main加载程序逻辑:

/**
* Created by xkfx on 2016/12/14.
*/
public class ConstructorTest{
public static void main(String[] args){
Employee[] staff = new Employee[3];

staff[0] = new Employee("xkfx" , 30000);
staff[1] = new Employee(60000);
staff[2] = new Employee();

for(Employee e: staff){
System.out.println(e.getId()+" "+e.getName()+" "+e.getSalary());
}
}
}

网上copy的一段不知道有没有误

java程序在内存中的存储分配情况： 堆区: 1.存储的全部是对象，每个对象都包含一个与之对应的class的信息。(class的目的是得到操作指令) 2.jvm只有一个堆区(heap)被所有线程共享，堆中不存放基本类型和对象引用，只存放对象本身 栈区: 1.每个线程包含一个栈区，栈中只保存基础数据类型的对象和自定义对象的引用(不是对象)，对象都存放在堆区中 2.每个栈中的数据(原始类型和对象引用)都是私有的，其他栈不能访问。 3.栈分为3个部分：基本类型变量区、执行环境上下文、操作指令区(存放操作指令)。 方法区: 1.又叫静态区，跟堆一样，被所有的线程共享。方法区包含所有的class和static变量。 2.方法区中包含的都是在整个程序中永远唯一的元素，如class，static变量。