CODEWITHSUNDEEP
javaexception
kane77
kane77

Reputation: 591

How to correctly close resources?

I have methods that all propagate exceptions and then I have handling on one place, however I realized something.

Let's say I have method like this

public void foo() throws Exception e {
  Statement stmt = createStatement();
  doSomething(stmt);
  stmt.close();
}

My issue is that if exception is thrown by doSometing() method the statement will not be closed, but I don't want to handle exception there. Is the right approach to have try and catch that only rethrows exception and finally to close statement?

Upvotes: 1

Views: 347

Answers (4)

Alexander Pogrebnyak
Alexander Pogrebnyak

Reputation: 45576

Modification to nos answer. You actually may initialize stmt before try block. That way there is no need to see if it's null, so this just suffice:

public void foo() throws Exception e {

  final Statement stmt = createStatemnt( );

  try {
    doSomething(stmt);
  } finally {
    stmt.close();
  }
}

Upvotes: 1

HeDinges
HeDinges

Reputation: 4607

Yes, you can throw the exception further

try {
   stmt = createStatement();
   doSomething(stmt);
}
 catch (Exception e) {
    throw e;
}
finally {
   if(stmt != null) 
      stmt.close();
}

Upvotes: -1

nos
nos

Reputation: 229088

public void foo() throws Exception e {

  Statement stmt = null ; 
  try {
    stmt = createStatement();
    doSomething(stmt);
  } finally {
    if(stmt != null) 
      stmt.close();
  }
}

Upvotes: 6

Padmarag
Padmarag

Reputation: 7214

Close it in finally block. All resources opened should be released/closed.
See this for more - http://www.ibm.com/developerworks/java/library/j-jtp03216.html

Upvotes: 2

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