Achieving High Performance Application in Java Coding! – Part 3

TnT Admin — Mon, 08 Feb 2010 15:22:07 +0000

Code with performance in mind! Follow these next 7 good coding practises that can be easily achieved for high performance!

Beware of “Thread.run()” versus the real intend of “Thread.start()” – We may unknowingly code the thread as “run()”. This will cause the thread to run sequentially instead of concurrently. Beware of this! Use “Thread.start()” to allow the thread to run concurrently.
Use “String.length () == 0” instead of “String.equals(“”)” – Both constructs do the same thing of comparing if any characters exists for the string. However, the first construct, “String.length() == 0” is more efficient than the latter one.
Avoid calling “String.toCharArray()” – “toCharArray()” method is inefficient as the method reallocates the entire array stored in the string. However, sometimes this is necessary. Therefore, as a rule, avoid using “toCharArray()” method if possible. If not possible, do use it with care.
Place “try/catch/finally” block outside loop – Placing “try/catch/finally” blocks inside loops can slow down the execution of code. Do take note that moving the “try/catch/finally” block outside the loop can change program behaviour. An exception that has the “try/catch/finally” block outside the loop will terminate early. On the other hand, the “try/catch/finally” block inside the loop may cause the program to continue iterating over the loop even after an exception has occurred.
Use “StringBuffer.Append ()” instead of “+=” operators for concatenating strings – “Append()” has better improvement over “+=” operators and its recommended to use it instead of “+=” operators for concatenating strings.
Do not use “StringBuffer” as constants – Dynamically resizable strings are unnecessary for constant strings (as they do not change). Instead, use “String” for non-modifiable string constants.
Do not open or close JDBC connections in loops – It is inefficient to open and close a connection in loop. Instead, the connection should be opened before the loop and closed after the loop to avoid redundant calls make to the database.

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Achieving High Performance Application in Java Coding! – Part 3