需求:用户名密码注册,用户名不得少于6位字符,否则提示:姓名不能少于6位!
/*
1.自定义无效名字异常:
1.编译时异常,直接继承Exception
2.运行时异常,直接继承RuntimeException
*/
public class IllegalNameException extends Exception{//编译时异常 //public class TestName06 extends RuntimeException{//运行时异常 //定义异常一般提供两个构造方法 public IllegalNameException(){} public IllegalNameException(String msg){ super(msg); } }
2.用户注册
/* 用户注册 */ public class CustomerSercvices { public void Register(String name) throws IllegalNameException{ //注册异常 if(name.length()<6){ //IllegalNameException ine=new IllegalNameException("姓名不能小于6位"); //throw ine; throw new IllegalNameException("姓名不能小于6位!"); } //完成注册 System.out.println("注册成功!"); } }
3.测试程序
public class Test { public static void main(String[] args){ String username="jack"; CustomerSercvices cs=new CustomerSercvices(); try{ cs.Register(username); }catch(IllegalNameException e){ System.out.println(e.getMessage());//姓名不能小于6位! } } }