1.AboutException.java

源代码：

package 动手动脑;import javax.swing.*;publicclass AboutException {    publicstaticvoid main(String[] args)        {    inti=1, j=0, k;    k=i/j;        try        {                        k = i/j;    // Causes division-by-zero exception            //throw new Exception("Hello.Exception!");        }                catch ( ArithmeticException e)        {            System.out.println("被0除.  "+ e.getMessage());        }                catch (Exception e)        {            if (einstanceof ArithmeticException)                System.out.println("被0除");            else            {                  System.out.println(e.getMessage());                            }        }                finally         {            JOptionPane.showConfirmDialog(null,"OK");         }                  }}

运行截图：

 

Try中监测“k=i/j;”这一语句，当j等于0时给出错误。

 

2

 

这是因为两段程序在编译之后生成的是不同的字节码指令，JVM在具体实现这两个指令时采用的是不同的方法，所以会出现不同的结果。

3.CatchWho.java

package 动手动脑;publicclass CatchWho {    publicstaticvoid main(String[] args) { try {     try {     thrownew ArrayIndexOutOfBoundsException();     }     catch(ArrayIndexOutOfBoundsException e) {         System.out.println(  "ArrayIndexOutOfBoundsException" +  "/内层try-catch");     }thrownew ArithmeticException();         } catch(ArithmeticException e) {             System.out.println("发生ArithmeticException");         } catch(ArrayIndexOutOfBoundsException e) {            System.out.println(  "ArrayIndexOutOfBoundsException" + "/外层try-catch");         }     } }

4CatchWho2.java

public class CatchWho2 {     public static void main(String[] args) {         try {    try {     throw new ArrayIndexOutOfBoundsException();     }     catch(ArithmeticException e) {     System.out.println( "ArrayIndexOutOfBoundsException" + "/内层try-catch");     }            throw new ArithmeticException();         }         catch(ArithmeticException e) {             System.out.println("发生ArithmeticException");         }         catch(ArrayIndexOutOfBoundsException e) {             System.out.println( "ArrayIndexOutOfBoundsException" + "/外层try-catch");         }     } }

5  EmbededFinally.Java

public class EmbededFinally {    public static void main(String args[]) {        int result;        try {            System.out.println("in Level 1");            try {                System.out.println("in Level 2");  // result=100/0;  //Level 2                try {                    System.out.println("in Level 3");                    result=100/0;  //Level 3                }                 catch (Exception e) {                    System.out.println("Level 3:" + e.getClass().toString());                }                finally {                    System.out.println("In Level 3 finally");                }                // result=100/0;  //Level 2                }            catch (Exception e) {                System.out.println("Level 2:" + e.getClass().toString());            }            finally {                System.out.println("In Level 2 finally");             }            // result = 100 / 0;  //level 1        }         catch (Exception e) {            System.out.println("Level 1:" + e.getClass().toString());        }        finally {.            System.out.println("In Level 1 finally");        }    }}

6SystemExitAndFinally.java

public class SystemExitAndFinally {    public static void main(String[] args)    {        try{            System.out.println("in main");            throw new Exception("Exception is thrown in main");        //System.exit(0);        }        catch(Exception e)            {            System.out.println(e.getMessage());            System.exit(0);        }        finally        {            System.out.println("in finally");        }    }}

7PrintExceptionStack.java

// UsingExceptions.java// Demonstrating the getMessage and printStackTrace// methods inherited into all exception classes.public class PrintExceptionStack {   public static void main( String args[] )   {      try {         method1();      }      catch ( Exception e ) {         System.err.println( e.getMessage() + "\n" );         e.printStackTrace();      }   }   public static void method1() throws Exception   {      method2();   }   public static void method2() throws Exception   {      method3();   }   public static void method3() throws Exception   {      throw new Exception( "Exception thrown in method3" );   }}