JavaBean Rules

The JavaBeans Ruleset catches instances of bean rules not being followed.

BeanMembersShouldSerialize

Since: PMD 1.1

If a class is a bean, or is referenced by a bean directly or indirectly it needs to be serializable. Member variables need to be marked as transient, static, or have accessor methods in the class. Marking variables as transient is the safest and easiest modification. Accessor methods should follow the Java naming conventions, i.e.if you have a variable foo, you should provide getFoo and setFoo methods.

This rule is defined by the following Java class: net.sourceforge.pmd.rules.BeanMembersShouldSerializeRule

Example:

                

  private transient int someFoo;//good, it's transient
  private static int otherFoo;// also OK
  private int moreFoo;// OK, has proper accessors, see below
  private int badFoo;//bad, should be marked transient


  private void setMoreFoo(int moreFoo){
        this.moreFoo = moreFoo;
  }

  private int getMoreFoo(){
        return this.moreFoo;
  }


    
            

This rule has the following properties:

NameDefault valueDescription
prefix A variable prefix to skip, i.e., m_

MissingSerialVersionUID

Since: PMD 3.0

Classes that are serializable should provide a serialVersionUID field.

This rule is defined by the following XPath expression:

    
//ClassOrInterfaceDeclaration
 [
  count(ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration
   /FieldDeclaration/VariableDeclarator/VariableDeclaratorId[@Image='serialVersionUID']) = 0
and
  count(ImplementsList
   [ClassOrInterfaceType/@Image='Serializable'
   or ClassOrInterfaceType/@Image='java.io.Serializable']) =1
and
   @Abstract = 'false'
]

              

Example:

                

public class Foo implements java.io.Serializable {
 String name;
 // Define serialization id to avoid serialization related bugs
 // i.e., public static final long serialVersionUID = 4328743;
}