extrafeatures.java

java的异常部分ppt

//: c10:ExtraFeatures.java
// From 'Thinking in Java, 2nd ed.' by Bruce Eckel
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
// Further embellishment of exception classes.

class MyException2 extends Exception {
  public MyException2() {}
  public MyException2(String msg) {
    super(msg);
  }
  public MyException2(String msg, int x) {
    super(msg);
    i = x;
  }
  public int val() { return i; }
  private int i;
}

public class ExtraFeatures {
  public static void f() throws MyException2 {
    System.out.println(
      "Throwing MyException2 from f()");
    throw new MyException2();
  }
  public static void g() throws MyException2 {
    System.out.println(
      "Throwing MyException2 from g()");
    throw new MyException2("Originated in g()");
  }
  public static void h() throws MyException2 {
    System.out.println(
      "Throwing MyException2 from h()");
    throw new MyException2(
      "Originated in h()", 47);
  }
  public static void main(String[] args) {
    try {
      f();
    } catch(MyException2 e) {
      e.printStackTrace(System.err);
    }
    try {
      g();
    } catch(MyException2 e) {
      e.printStackTrace(System.err);
    }
    try {
      h();
    } catch(MyException2 e) {
      e.printStackTrace(System.err);
      System.err.println("e.val() = " + e.val());
    }
  }
} ///:~