Java-用户自定义异常
1.如何自定义异常
- 继承现有的异常父类：RuntimeException、Exception
- 提供全局常量：serialVersionUID
- 提供重载的构造器
2.code举例
定义：
package p8exception.p9;
public class MyException extends RuntimeException{
static final long serialVersionUID = -7023444L;
public MyException() {
}
public MyException(String message) {
super(message);
}
}
使用：
package p8exception.p9;
public class StudentTest {
public static void main(String[] args) {
Student s = new Student();
try {
s.regist(-1001);
System.out.println(s);
} catch (Exception e) {
System.out.println(e.getMessage());
}
}
}
class Student {
private int id;
public void regist(int id){
if(id > 0) {
this.id = id;
}else {
// System.out.println("非法");
// throw new RuntimeException("输入非法");
throw new MyException("输入非法");
}
}
@Override
public String toString() {
return "Student{" +
"id=" + id +
'}';
}
}
