/** {@inheritDoc} */
public int checkReturnTag(final int aTagIndex,
                          JavadocTag[] aTags,
                          int aLineNo)
        

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

public class Example1 {

  /** */
  Example1(int x) {}
  // violation above, 'Expected @param tag for 'x''
  /** */
  public int m1(int p1) { return p1; }
  // 2 violations above:
  //    '@return tag should be present'
  //    'Expected @param tag for 'p1''

  /**
   * @param p1 The first number
   */
  @Deprecated
  private int m2(int p1) { return p1; }
  // violation 2 lines above '@return tag should be present'

  /** */
  void m3(int p1) {}
  // violation above, 'Expected @param tag for 'p1''
}
        

<module name="Checker">
  <module name="TreeWalker">
    <module name="JavadocMethod">
      <property name="accessModifiers" value="public"/>
      <property name="allowMissingParamTags" value="true"/>
    </module>
  </module>
</module>
        

public class Example2 {

  /** */
  Example2(int x) {}

  /** */
  public int m1(int p1) { return p1; }
  // 1 violations above:
  //    '@return tag should be present'
  // OK, No missing param tag violation

  /**
   * @param p1 The first number
   */
  @Deprecated
  private int m2(int p1) { return p1; }
  // OK, only public methods are checked

  /** */
  void m3(int p1) {}

}
        

<module name="Checker">
  <module name="TreeWalker">
    <module name="JavadocMethod">
      <property name="accessModifiers" value="private, package"/>
    </module>
  </module>
</module>
        

public class Example3 {

  /** */
  Example3(int x) {}

  /** */
  public int m1(int p1) { return p1; }
  // OK, No missing param tag violation
  // OK, No missing @return tag violation
  // only private, package are checked

  /**
   * @param p1 The first number
   */
  @Deprecated
  private int m2(int p1) { return p1; }
  // OK, No missing @return tag violation

  /** */
  void m3(int p1) {}

}
        

<module name="Checker">
  <module name="TreeWalker">
    <module name="JavadocMethod">
        <property name="allowMissingReturnTag" value="true"/>
    </module>
  </module>
</module>
        

public class Example4 {

  /** */
  Example4(int x) {}
  // violation above, 'Expected @param tag for 'x''
  /** */
  public int m1(int p1) { return p1; }
  // 1 violations above:
  //    'Expected @param tag for 'p1''
  // OK, No missing @return tag violation

  /**
   * @param p1 The first number
   */
  @Deprecated
  private int m2(int p1) { return p1; }
  // OK, No missing @return tag violation

  /** */
  void m3(int p1) {}
  // violation above, 'Expected @param tag for 'p1''
}
        

<module name="Checker">
  <module name="TreeWalker">
    <module name="JavadocMethod">
        <property name="allowedAnnotations" value="Deprecated"/>
    </module>
  </module>
</module>
        

public class Example5 {

  /** */
  Example5(int x) {}
  // violation above, 'Expected @param tag for 'x''
  /** */
  public int m1(int p1) { return p1; }
  // 2 violations above:
  //    '@return tag should be present'
  //    'Expected @param tag for 'p1''

  /**
   * @param p1 The first number
   */
  @Deprecated
  private int m2(int p1) { return p1; }
  // OK, No missing @return tag violation

  /** */
  void m3(int p1) {}
  // violation above, 'Expected @param tag for 'p1''
}
        

<module name="Checker">
  <module name="TreeWalker">
    <module name="JavadocMethod">
        <property name="tokens" value="CTOR_DEF"/>
    </module>
  </module>
</module>
        

public class Example6 {

  /** */
  Example6(int x) {}
  // violation above, 'Expected @param tag for 'x''
  /** */
  public int m1(int p1) { return p1; }
  // OK, No missing param tag violation
  // OK, No missing @return tag violation
  // only constructors are checked

  /**
   * @param p1 The first number
   */
  @Deprecated
  private int m2(int p1) { return p1; }
  // OK, No missing @return tag violation

  /** */
  void m3(int p1) {}

}
        

<module name="Checker">
  <module name="TreeWalker">
    <module name="JavadocMethod">
      <property name="validateThrows" value="true"/>
    </module>
  </module>
</module>
        

public class Example7 {

  /**
   * Actual exception thrown is child class of class that is declared in throws.
   * It is limitation of checkstyle (as checkstyle does not know type hierarchy).
   * Javadoc is valid not declaring FileNotFoundException
   * BUT checkstyle can not distinguish relationship between exceptions.
   * @param file some file
   * @throws IOException if some problem
   */
  public void doSomething8(File file) throws IOException {
    if (file == null) {
      // violation below, 'Expected @throws tag for 'FileNotFoundException''
      throw new FileNotFoundException();
    }
  }

  /**
   * Exact throw type referencing in javadoc even first is parent of second type.
   * It is a limitation of checkstyle (as checkstyle does not know type hierarchy).
   * This javadoc is valid for checkstyle and for javadoc tool.
   * @param file some file
   * @throws IOException if some problem
   * @throws FileNotFoundException if file is not found
   */
  public void doSomething9(File file) throws IOException {
    if (file == null) {
      throw new FileNotFoundException();
    }
  }

  /**
   * Ignore try block, but keep catch and finally blocks.
   *
   * @param s String to parse
   * @return A positive integer
   */
  public int parsePositiveInt(String s) {
    try {
      int value = Integer.parseInt(s);
      if (value <= 0) {
        throw new NumberFormatException(value + " is negative/zero"); // ok, try
      }
      return value;
    } catch (NumberFormatException ex) {
      // violation below, 'Expected @throws tag for 'IllegalArgumentException''
      throw new IllegalArgumentException("Invalid number", ex);
    } finally {
      // violation below, 'Expected @throws tag for 'IllegalStateException''
      throw new IllegalStateException("Should never reach here");
    }
  }

  /**
   * Try block without catch is not ignored.
   *
   * @return a String from standard input, if there is one
   */
  public String readLine() {
    try (Scanner sc = new Scanner(System.in)) {
      if (!sc.hasNext()) {
        // violation below, 'Expected @throws tag for 'IllegalStateException''
        throw new IllegalStateException("Empty input");
      }
      return sc.next();
    }
  }

  /**
   * Lambda expressions are ignored.
   *
   * @param s a String to be printed at some point in the future
   * @return a Runnable to be executed when the string is to be printed
   */
  public Runnable printLater(String s) {
    return () -> {
      if (s == null) {
        throw new NullPointerException();
      }
      System.out.println(s);
    };
  }
}