普通静态初始化，按声明顺序执行
静态初始化块
普通实例初始化，按声明顺序执行
实例初始化块
构造函数

有父类的，先执行父类初始化



测试代码 InitTest.java

public class InitTest {
	private int num4 = getNum4();
	private int num3 = getNum3();
	
	private static int num2 = getNum2();
	private static int num1 = getNum1();
	
	public InitTest(){		
		System.out.println("InitTest() run");	
	}
	// init 
	{	
		System.out.println("init block run");	
	}
	// static init
	static{
		System.out.println("static init block run");
	}

	
	public static void main(String[] args) throws Exception {
		InitTest test = new InitTest();	
		System.out.println(test.toString());
	}
	
	private static int getNum1(){
		System.out.println("getNum1() run");
		return 1;
	}
	
	private static int getNum2(){
		System.out.println("getNum2() run");
		return 2;
	}
	
	private static int getNum3(){
		System.out.println("getNum3() run");
		return 3;
	}
	
	private static int getNum4(){
		System.out.println("getNum4() run");
		return 4;
	}
	
	public String toString(){
		return String.format("num1=%d,num2=%d,num3=%d,num4=%d", num1,num2,num3,num4);
	}

}



输出结果

getNum2() run
getNum1() run
static init block run
getNum4() run
getNum3() run
init block run
InitTest() run
num1=1,num2=2,num3=3,num4=4