编辑代码

class Main {
    
    public static void reada( String name,int age) 
    { 
        System.out.println("大家好，我是" + name + ",我在看书!"+"我的年龄为"+age);
    }

    public static void main(String[] args) 
    {
        System.out.println("Hello world!   - java.jsrun.net ");
        reada("张三",19);
        Student stu1= new Student();
        stu1.name="李四";
        //stu1.age=19;
        stu1.setAge(-18);
        stu1.read();

        Student stu2= new Student();
        stu2.name="王五";
        //stu2.age=-21;
        stu2.setAge(22);
        stu2.read();
        stu2.qqname("张","女");
        stu2.read();
    }

}


class Student 
{
     String name;        
    private int age;           
    String  sex;        
    public void read() 
    {  
        System.out.println("大家好，我是" + name + ",我在看书!"+"我的年龄为"+age);
    }
    public void setAge(int age)
    {
     if(age<0){System.out.println(name+"的年龄设置有错误");}
     else 
     this.age=age;
    }
    
    public void qqname(String xing,String sex) 
    {
     int num = (int)(Math.random()*10);
     System.out.println("取："+this.name); 
     System.out.println("取取："+sex.equals("女")); 

     if(sex.equals("男"))
        {
     switch(num) 
            {
      case 1: this.name=xing+"仗";  break;
      case 2: this.name=xing+"剑";  break;
      case 3:   this.name=xing+"走";  break;
      case 4:   this.name=xing+"天";  break;
      case 5:   this.name=xing+"涯";  break;
      case 6:   this.name=xing+"坤"; break;
      default: System.out.println("取名不成功"); break;
            }
        } 

       if(sex.equals("女"))
    {
      switch(num) 
        {
      case 1: this.name=xing+"春";  break;
      case 2: this.name=xing+"暖";  break;
      case 3:   this.name=xing+"花";  break;
      case 4:   this.name=xing+"开";  break;
      case 5:   this.name=xing+"月";  break;
      case 6:   this.name=xing+"园"; break;
      default: System.out.println("取名不成功"); break;
        }     
     } 
  }  
}