AnnotationOnSameLine

Since Checkstyle 8.2

Description

Checks that annotations are located on the same line with their targets. Verifying with this check is not good practice, but it is using by some style guides.

Properties

Examples

To configure the check:


<module name="Checker">
  <module name="TreeWalker">
    <module name="AnnotationOnSameLine"/>
  </module>
</module>

Example:


@Deprecated interface Foo1 {
  void doSomething();
}

class Example1 implements Foo1 {

  // violation below, "should be on the same line with its target."
  @SuppressWarnings("deprecation")
  public Example1() {
  }

  @SuppressWarnings("unchecked") public void fun2() {}

  public void fun1() {}

  // violation below, "should be on the same line with its target."
  @Nullable
  String s;
  // violation below, "should be on the same line with its target."
  @Override
  public void doSomething() {}
}

@SuppressWarnings("unchecked") class Test1 extends Example1 {

  @Deprecated public Test1() {
  }

  @Override // violation, "should be on the same line with its target."
  public void fun1() {}

  @Before // violation, "should be on the same line with its target."
  @Override public void fun2() {}

  // violation below, "should be on the same line with its target."
  @SuppressWarnings("deprecation")
  @Before public void fun3() {
  }

}

To configure the check to check for annotations applied on interfaces, variables and constructors:


<module name="Checker">
  <module name="TreeWalker">
    <module name="AnnotationOnSameLine">
      <property name="tokens"
                value="INTERFACE_DEF, VARIABLE_DEF, CTOR_DEF"/>
    </module>
  </module>
</module>

Example:


@Deprecated interface Foo2 {
  void doSomething();

}

class Example2 implements Foo2 {

  // violation below, "should be on the same line with its target."
  @SuppressWarnings("deprecation")
  public Example2() {
  }

  @SuppressWarnings("unchecked") public void fun2() {}

  public void fun1() {}

  // violation below, "should be on the same line with its target."
  @Nullable
  String s;

  @Override
  public void doSomething() {}
}

@SuppressWarnings("unchecked") class Test2 extends Example2 {

  @Deprecated public Test2() {
  }

  @Override
  public void fun1() {}

  @Before
  @Override public void fun2() {}

  @SuppressWarnings("deprecation")
  @Before public void fun3() {
  }

}

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.

Fully Qualified Name

com.puppycrawl.tools.checkstyle.checks.annotation.AnnotationOnSameLineCheck

Use this fully qualified class name in configuration when an exact class reference is required.

Parent Module

TreeWalker