Header

Since Checkstyle 6.9

Description

Checks that a source file begins with a specified header. Property headerFile specifies a file that contains the required header. Alternatively, the header specification can be set directly in the header property without the need for an external file.

Property ignoreLines specifies the line numbers to ignore when matching lines in a header file. This property is very useful for supporting headers that contain copyright dates. For example, consider the following header: 

line 1: ////////////////////////////////////////////////////////////////////
line 2: // checkstyle:
line 3: // Checks Java source code for adherence to a set of rules.
line 4: // Copyright (C) 2002  Oliver Burn
line 5: ////////////////////////////////////////////////////////////////////

Since the year information will change over time, you can tell Checkstyle to ignore line 4 by setting property ignoreLines to 4.

Notes

In default configuration, if header is not specified, the default value of header is set to null and the check does not rise any violations.

Properties

name description type default value since
charset Specify the character encoding to use when reading the headerFile. String the charset property of the parent <a href="https://checkstyle.org/config.html#Checker">Checker</a> module 5.0
fileExtensions Specify the file extensions of the files to process. String[] all files 6.9
header Specify the required header specified inline. Individual header lines must be separated by the string "\n"(even on platforms with a different line separator). String null 5.0
headerFile Specify the name of the file containing the required header. URI null 3.2
ignoreLines Specify the line numbers to ignore. int[] {} 3.2

Examples

To configure the check such that no violations arise. Default values of properties are used. 

<module name="Checker">
  <module name="Header"/>
</module>

To configure the check to use header file "config/java.header" and ignore lines 2, 3, and 4 and only process Java files: 

<module name="Checker">
  <module name="Header">
    <property name="headerFile" value="config/java.header"/>
    <property name="ignoreLines" value="2, 3, 4"/>
    <property name="fileExtensions" value="java"/>
  </module>
</module>

To configure the check to verify that each file starts with the header 

// Copyright (C) 2004 MyCompany
// All rights reserved

without the need for an external header file: 

<module name="Checker">
  <module name="Header">
    <property name="header"
      value="// Copyright (C) 2004 MyCompany\n// All rights reserved"/>
  </module>
</module>

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.header

Parent Module

Checker