The Java Language: Exceptions: Throwing Exceptions:The finally Clause

What if we have something important to do before we exit our method from one of the catch clauses? To avoid duplicating the code in each catch branch and to make the cleanup more explicit, you can use the finally clause. A finally clause can be added after a try and any associated catch clauses. Any statements in the body of the final ly clause are guaranteed to be executed no matter how control leaves the try body, whether an exception was thrown or not:

 try {  
 // Do something here  
 }  
 catch ( FileNotFoundException e ) {  
 ...  
 }  
 catch ( IOException e ) {  
 ...  
 }  
 catch ( Exception e ) {  
 ...  
 }  
 finally {  
 // Cleanup here is always executed  
 }  

In this example, the statements at the cleanup point are executed eventually, no matter how control leaves the try. If control transfers to one of the catch clauses, the statements in finally are executed after the catch completes. If none of the catch clauses handles the exception, the finally statements are executed before the exception propagates to the next level. If the statements in the try execute cleanly, or if we perform a return , break, or continue, the statements in the finally clause are still executed. To guarantee that some operations will run, we can even use try and finally without any catch clauses:

 try {  
 // Do something here  
 return;  
 }  
 finally {  
 System.out.println("Whoo-hoo!");  
 }  

Exceptions that occur in a catch or finally clause are handled normally; the search for an enclosing try/catch begins outside the offending try statement, after the fi nally has been executed.