/**
 * <p>title: 捕获异常和实现自己的异常类</p>
 * <p>description: 通过继承exception类来实现自己的异常类。并使用try－catch来捕获这个异常。</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 :)