MissingOverride

Since Checkstyle 5.0

Description

Verifies that the @Override annotation is present when the @inheritDoc javadoc tag is present.

Rationale: The @Override annotation helps compiler tools ensure that an override is actually occurring. It is quite easy to accidentally overload a method or hide a static method and using the @Override annotation points out these problems.

This check will log a violation if using the @inheritDoc tag on a method that is not valid (ex: private, or static method).

There is a slight difference between the @Override annotation in Java 5 versus Java 6 and above. In Java 5, any method overridden from an interface cannot be annotated with @Override. In Java 6 this behavior is allowed.

As a result of the aforementioned difference between Java 5 and Java 6, a property called javaFiveCompatibility is available. This property will only check classes, interfaces, etc. that do not contain the extends or implements keyword or are not anonymous classes. This means it only checks methods overridden from java.lang.Object. Java 5 Compatibility mode severely limits this check. It is recommended to only use it on Java 5 source.

Properties

name description type default value since
javaFiveCompatibility Enable java 5 compatibility mode. boolean false 5.0

Examples

To configure the check:

<module name="MissingOverride"/>
        

Example:

class Test extends SuperClass {

    /** {@inheritDoc} */
    @Override
    public void test1() { // OK

    }

    /** {@inheritDoc} */
    public void test2() { // violation, should be annotated with @Override

    }

    /** {@inheritDoc} */
    private void test3() { // violation, using the @inheritDoc tag on private method

    }

    /** {@inheritDoc} */
    public static void test4() { // violation, using the @inheritDoc tag on static method

    }
}
        

To configure the check for the javaFiveCompatibility mode:

<module name="MissingOverride">
  <property name="javaFiveCompatibility"
      value="true"/>
</module>
        

Example:

class Test1 {

    /** {@inheritDoc} */
    public void equals() { // violation, should be annotated with @Override

    }
}

interface Test2 {

    /** {@inheritDoc} */
    void test(); // violation, should be annotated with @Override
}

class Test3 extends SuperClass {

    /** {@inheritDoc} */
    public void test() { // OK, is ignored because class extends other class

    }
}

class Test4 implements SuperInterface {

    /** {@inheritDoc} */
    public void test() { // OK, is ignored because class implements interface

    }
}

class Test5 {
    Runnable r = new Runnable() {

        /** {@inheritDoc} */
        public void run() { // OK, is ignored because class is anonymous class

        }
    };
}
        

Example of Usage

Violation Messages

All messages can be customized if the default message doesn't suit you. Please see the documentation to learn how to.

Package

com.puppycrawl.tools.checkstyle.checks.annotation

Parent Module

TreeWalker