Header.md

Pattern: Malformed file header

Issue: -

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.

Examples

In default configuration the check does not rise any violations. Default values of properties are used.

<module name="Header"/>

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="Header">
    <property name="headerFile" value="config/java.header"/>
    <property name="ignoreLines" value="2, 3, 4"/>
    <property name="fileExtensions" value="java"/>
</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="Header">
    <property name="header"
 value="// Copyright (C) 2004 MyCompany\n// All rights reserved"/>
</module>

Further Reading

• checkstyle - Header