I/O设备等资源，将让出CPU并暂时停止自己的运行，进入状态.

public class ToStringTest{ static inti = 1;

public static void main( String args[]){

System.out.println('love " + new ToStringTestO)^/love j ava

ToStringTest a = new ToStringTestO；

a.i++;

System.out.println("me "+ ai)//me 2

}

public String toString(){

System.out.print('I '5^/1 return 'java";

}

}

public class CalendarDemo {

public static void main( Strin[] args) {

Calendar cal=Calendar getInstance();

cal.set(2020:2,14);

cal.setLenient(false);

System.outprintln(cal.get(Calendar.MONIH)+"月 }

}

import java.math.BigInteger; 

public class BiglntegerDemo {

 public static void main( String[]args) {

 Biglnteger x=newBigInteger('3");

 Biglnteger y=new Biglnteger('7'); 

Biglnteger z=x.add(y);

System.out.println("x="+x+"y="+y+"z="+z); }

}

中的 ___类似.创建包的语句必须是文件的第__ 个语句