静态块java

public class Demo4_9{
public class void main(String[]args){
Student p1=new Student("s1初始化")；
}}
class Book(String str){
System.out.println(str);
}}
class Student{
Book book1=new Book("book1成员变量初始化");
static Book book2=new Book("book2成员变量(static成员)初始化");
public Student(String msg);
}
Book book3=new Book("book3成员变量初始化");
static Book book4=new Book("book4成员变量(static成员)初始化");
static{
System.out.println("我是student的静态代码块");
}}