Wednesday, October 17, 2007

String empty check is more easy now with JDK6

Prior to JDK 6, we can check if a string is empty in 2 ways:

if(s != null && s.length() == 0)

Checking its length is more readable and may be a little faster. Starting from JDK 6, String class has a new convenience method isEmpty():

boolean isEmpty()
Returns true if, and only if, length() is 0.

It is just a shorthand for checking length. Of course, if the String is null, you will still get NullPointerException.
I don't see much value in adding this convenience method. Instead,
I'd like to see a static utility method that also handle null value:

public static boolean notEmpty(String s) {
return (s != null && s.length() > 0);

Another option, use StringUtils.isEmpty(String str) of Apache commons , can be downloaded from

It checks for null string also and return true for empty

public static boolean isEmpty(String str) {
return str == null str.length() == 0;

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