（1）多層的異常捕獲1

package Demo1;

public class CatchWho {
    public static void main(String[] args) { 
        try { 
                try { 
                    throw new ArrayIndexOutOfBoundsException(); 
                } 
                catch(ArrayIndexOutOfBoundsException e) { 
                       System.out.println(  
 
"ArrayIndexOutOfBoundsException" +  "/內層try-catch"); 
                }
 
            throw new ArithmeticException(); 
        } 
        catch(ArithmeticException e) { 
            System.out.println("發生ArithmeticException"); 
        } 
        catch(ArrayIndexOutOfBoundsException e) { 
           System.out.println(  
 
"ArrayIndexOutOfBoundsException" + "/外層try-catch"); 
        } 
    } 

}

結果：

（2）多層的異常捕獲2

package Demo1;

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

}

結果：

（3）多層異常捕獲3

    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");
        
        }
    
    }

 結果：

（4）finally語句是否一定會執行？

    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");
        }
    }

結果：

結論：

  很明顯，根據結果來看，finally語句並不是一定要執行的，而不執行的條件根據除錯便可以知道：

System.exit(0);

System.exit(0);語句是會打斷finally的正常執行的。