java异常类

 package shb.java.exception;
 /**
  * 测试异常类
  * @Package:shb.java.exception
  * @Description：
  * @author shaobn
  * @Date 2015-9-7上午11:52:42
  */
 public class Demo_2 {
     public static void main(String[] args) {
         testTD_5();
     }
     public static void testTD_2(){
         TDemo_2 td_2 = new TDemo_2();
         try {
             td_2.getResult(9, 0);//一旦发生异常，函数中后面的方法不再执行即结束
             System.out.println("over");//发生异常后，此句已不能再执行。    直接抛出异常对象，由catch块中异常对象的引用来接收。
         } /*catch (Exception e) {
             // TODO: handle exception
             System.out.println(e.getMessage());
         }*///如果一开始就用Exception会覆盖子异常类，则会只执行Exception，其余都不能执行。
         catch (ArithmeticException ae) {
             // TODO: handle exception
             System.out.println(ae.getMessage());
             System.out.println("算术异常");
         }catch (ArrayIndexOutOfBoundsException aiobe) {
             // TODO: handle exception
             System.out.println(aiobe.getMessage());
             System.out.println("数组越界异常");
         }
         System.out.println("helloworld");
     }
     //自定义异常类
     public static void testTD_3(){
         TDemo_3 td_3 = new TDemo_3();
         try {
             td_3.getResult_3(9, 0);
             System.out.println("over");
         } catch (Exception e) {
             // TODO: handle exception
             System.out.println(e.getMessage());
         }
         System.out.println("hellobeijing");
     }
     //自定义的继承RuntimeException类的异常（编译时是不报错的，运行时检查异常）
     public static void testTD_4(){
 
         TDemo_4 td_4 = new TDemo_4();
         td_4.getResult(9, 0);
     }
     public static void testTD_5(){
         TDemo_5 td_5 = new TDemo_5();
         try {
             td_5.testMethod();
         } catch (Exception e) {
             // TODO: handle exception
             System.out.println("异常已经处理");
         }
     }
 }
 class TDemo_2{
     private int age = 10;
     public int getAge(){
         return this.age;
     }
     //声明两个异常，算术异常，数组越界异常。
     public int getResult(int a,int b) throws ArithmeticException,
     ArrayIndexOutOfBoundsException{
         byte[] arr = new byte[a];
         b = a/b;
         arr[a] = 9;
         return a/b;
     }
 }
 class TDemo_3{
     private int height = 90;
     public int getHeight(){
         return this.height;
     }
     public int getResult_3(int a,int b) throws TDemo_3Exception{
         if(b==0)
             //抛出自定义异常，必须在方法上声明异常类。
             throw new TDemo_3Exception("自定义的异常类");
         return a/b;
     }
 }
 //编译时被检测的异常
 class TDemo_3Exception extends Exception{
     public TDemo_3Exception(String str){
         super(str);
     }
     //重写getMessage()方法
     public String getMessage(){
         return super.getMessage();
     }
 
 }
 //编译时不被检测的异常
 class TDemo_4Exception extends RuntimeException{
     public TDemo_4Exception(String str){
         super(str);
     }
 }
 class TDemo_4{
     private int with = 90;
     public int getWith(){
         return this.with;
     }
     public int getResult(int a,int b){
         if(b==0)
             throw new TDemo_4Exception("自定义的runtime异常");
         return a/b;
 
     }
     public void testResult(int a,int b){
         if(b<0)
             throw new TDemo_4Exception("b小于0");
         System.out.println("测试成功");
     }
 
 }
 class TDemo_5Exception extends Exception{
 
     public TDemo_5Exception(String str){
         super(str);
     }
 
 }
 class TDemo_5{
     public void testMethod() throws TDemo_5Exception{
         TDemo_4 td_4 = new TDemo_4();
         try {
             td_4.testResult(9, -1);
         } catch (Exception e) {
             // TODO: handle exception
             throw new TDemo_5Exception("处理失败");
         }
 
     }
 }