JAVA代码块

package BlockDemo;

public class BlockTest {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String s=Person.desc;
		new Person();
	}

}
class Person{
	//属性
	String name;
	int age;
	static String desc="我是一个人";
	//构造器
	public Person() {
		// TODO Auto-generated constructor stub
	}
	public Person(String name,int age) {
		this.name=name;
		this.age=age;
	}
	//static的代码块
	static {
		System.out.println("hello,static block");
	}
	//非static的代码块
	{
		System.out.println("hello,非static block");
	}
	
	//方法
	public void eat() {
		System.out.println("吃饭");
	}
	@Override
	public String toString() {
		return "Person [name=" + name + ", age=" + age + "]";
	}
	public static void info() {
		System.out.println("我爱小徐");
	}
}

package BlockDemo;
//由父及子，静态先行，代码块先于构造器
public class LeafTest {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		new Leaf();
		new Leaf();
	}

}
class Root{
	static {
		System.out.println("Root的静态代码块");
	}
	{
		System.out.println("Root的非静态代码块");
	}
	public Root() {
		System.out.println("Root的无参构造器");
	}
}
class Mid extends Root{
	static {
		System.out.println("Mid的静态代码块");
	}
	{
		System.out.println("Mid的非静态代码块");
	}
	public Mid() {
		// TODO Auto-generated constructor stub
		System.out.println("Mid的无参构造器");
	}
	public Mid(String s) {
		this();
		System.out.println("Mid 的带参构造器，参数值为："+s);
	}
}
class Leaf extends Mid{
	static {
		System.out.println("Leaf 的静态代码块");
	}
	{
		System.out.println("Leaf的非静态代码块");
	}
	public Leaf() {
		// TODO Auto-generated constructor stub
		super("xt");
		System.out.println("Leaf的构造器");
	}
}