Common exception misuses in Java (and not only)

http://softwarecave.org/2014/03/22/common-exception-misuses-in-java/

by robertp1984 • 12 years ago

3 1 12 years ago

sigvef• 12 years ago

Though the author is correct in advising to do exception handling like this[1] instead of this[2], they are not correct in the reasoning behind it. In method [2], if a writer cannot be instanciated, the code will still try to write with it, which will probably cause a NullPointerException. Rewriting to method [1] hinders this.

[1]:

  Writer writer = null;
  try {
      writer = new FileWriter("/tmp/a");
      writer.write("Line1");
      writer.close();
  } catch(FileNotFoundException e) {
      // handle error
  } catch (IOException ex) {
      // handle error
  }
  
 [2]:
 
  Writer writer = null;
  try {
       writer = new FileWriter("/tmp/a");
  } catch(FileNotFoundException e) {
       // handle error
  } catch (IOException ex) {
       // handle error
  }       
  try {
       writer.write("Line1");
  } catch (IOException e) {
       // handle error
  }
  try {
       writer.close();
  } catch (IOException e) {
       // handle error
  }

Common exception misuses in Java (and not only)

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