[JAVA100例]009、异常的捕获和实现自己的异常类
/**
* <p>Title: 捕捉异常和实现自己的异常类</p>
* <p>Description: 通过继续Exception类来实现自己的异常类。并使用try－catch来捕捉这个异常。</p>
* <p>Copyright: Copyright (c) 2003</p>
* <p>Filename: </p>
* @version 1.0
*/
class MyException extends Exception {
public MyException() {}
public MyException(String msg) {
super(msg);
}
public MyException(String msg, int x) {
super(msg);
i = x;
}
public int val() { return i; }
private int i;
}
public class DemoException {
/**
*<br>方法说明：使用MyException类中默认的构造器
*<br>输入参数：
*<br>返回类型：
*/
public static void a() throws MyException {
System.out.println(
"Throwing MyException from a()");
throw new MyException();
}
/**
*<br>方法说明：使用MyException类中带信息的构造器
*<br>输入参数：
*<br>返回类型：
*/
public static void b() throws MyException {
System.out.println(
"Throwing MyException from b()");
throw new MyException("Originated in b()");
}
/**
*<br>方法说明：使用了MyException中有编码的构造器
*<br>输入参数：
*<br>返回类型：
*/
public static void c() throws MyException {
System.out.println(
"Throwing MyException from c()");
throw new MyException(
"Originated in c()", 47);
}
public static void main(String[] args) {
try {
a();
} catch(MyException e) {
e.getMessage();
}
try {
b();
} catch(MyException e) {
e.toString();
}
try {
c();
} catch(MyException e) {
e.printStackTrace();
System.out.println("error code: " + e.val());
}
}
} //end :)