How to avoid null checking in Java?

Question

I use object != null a lot to avoid NullPointerException.

Is there a good alternative to this?

For example I often use:

Answer 1

Depending on what kind of objects you are checking you may be able to use some of the classes in the apache commons such as: apache commons lang and apache commons collections

Example:

String foo;
...
if( StringUtils.isBlank( foo ) ) {
   ///do something
}

or (depending on what you need to check):

String foo;
...
if( StringUtils.isEmpty( foo ) ) {
   ///do something
}

The StringUtils class is only one of many; there are quite a few good classes in the commons that do null safe manipulation.

Here follows an example of how you can use null vallidation in JAVA when you include apache library(commons-lang-2.4.jar)

public DOCUMENT read(String xml, ValidationEventHandler validationEventHandler) {
    Validate.notNull(validationEventHandler,"ValidationHandler not Injected");
    return read(new StringReader(xml), true, validationEventHandler);
}

And if you are using Spring, Spring also has the same functionality in its package, see library(spring-2.4.6.jar)

Example on how to use this static classf from spring(org.springframework.util.Assert)

Assert.notNull(validationEventHandler,"ValidationHandler not Injected");