java best practices Archives

Java – What is serialVersionUID

May 14, 2020January 15, 2010 by mkyong

In Java, serialVersionUID is something like version control, assure both serialized and deserialized objects are using the compatible class. For example, if an object saved into a file (Serialization) with serialVersionUID=1L, when we convert the file back to an object (Derialization), we must use the same serialVersionUID=1L, otherwise an InvalidClassException is thrown. Terminal Exception in …

Constant value should always come first in comparison

August 30, 2012January 14, 2010 by mkyong

Normal practice Constant value comes second in comparison. private static final String COMPARE_VALUE = "VALUE123"; public boolean compareIt(String input){ if(input.equals(COMPARE_VALUE)){ return true; }else{ return false; } } Problem This is fine to compare a constant value with the above method, however it will potentially causing a NullPointerException, if user pass a “null” value for the …