java check null or empty code example

Example 1: check if string is null or empty java

if(str != null && !str.isEmpty()) { /* do your stuffs here */ }

Example 2: how to check null and empty string in java

if(str != null && !str.isEmpty())
Be sure to use the parts of && in this order, because java will not proceed to evaluate the second part if the first part of && fails, thus ensuring you will not get a null pointer exception from str.isEmpty() if str is null.

Example 3: check if a string is empty java

if (myString == null || myString.equals(""))
			throw new IllegalArgumentException("empty string");