CODEWITHSUNDEEP
javaexception
wuchang
wuchang

Reputation: 3069

How should I deal with the exception which happened in a catch block?

BufferedReader in
       = new BufferedReader(new FileReader(file));
     try {
        while((thisLine=in.readLine())!=null){
        ...  
        }
    } catch (IOException e) {
                    //in.close();
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

in the code above, I want to close the read buffer in the catch block.But I find that the function in.close also throws an IOException. It look ugly if I nest another try-catch block in the catch block.So ,what is the correct way to deal with such a problem?

Upvotes: 1

Views: 49

Answers (4)

Subhrajyoti Majumder
Subhrajyoti Majumder

Reputation: 41200

You can use finally block for that. finally-block execulated every time unless jvm exits abnormaly.

Java 7 try-with-resources statement to automatically close, you need to close resouce stream explicitly,

The try-with-resources statement is a try statement that declares one or more resources. A resource is an object that must be closed after the program is finished with it. The try-with-resources statement ensures that each resource is closed at the end of the statement. Any object that implements java.lang.AutoCloseable, which includes all objects which implement java.io.Closeable, can be used as a resource.

read more on documentaion

Example - 

try(BufferedReader in
       = new BufferedReader(new FileReader(file))){
  while((thisLine=in.readLine())!=null){
        ...  
  }
}catch (IOException e) {
  ...
}

Upvotes: 2

Suresh Atta
Suresh Atta

Reputation: 121998

Do in finally block,Which is specially meant for cleanup.

From finally block docs

The runtime system always executes the statements within the finally block regardless of what happens within the try block. So it's the perfect place to perform cleanup.

BufferedReader in
       = new BufferedReader(new FileReader(file));
     try {
        while((thisLine=in.readLine())!=null){
        ...  
        }
    } catch (IOException e) {
                    //in.close();
        // TODO Auto-generated catch block
        e.printStackTrace();
    }finally {
       in.close
}

Upvotes: 1

Gabriel Negut
Gabriel Negut

Reputation: 13960

try {
    in = new BufferedReader(new FileReader(file));
    // stuff here
} finally {
    try {
        in.close()
    } catch (IOException e) {} // ignore
}

Upvotes: 0

Juvanis
Juvanis

Reputation: 25950

Close the resources in a finally block, not in a catch block.

    try 
    {
      // actual code.
    } 
    catch (IOException e) {
      // handle exception
    }
    finally
    {
       try
       {
         in.close();
       }
       catch (IOException e) {
          // handle exception
       }  
    }

Upvotes: 1

Related Questions