Checks the header of the source against a fixed header file.
Rationale: In most projects each file must have a fixed header,
since usually the header contains copyright information.
The header contents are specified in the file identified by property
headerFile.
Property ignoreLines specifies the line numbers to ignore when
matching lines in a header file.
The property type is a comma-separated list of integers and defaults to an
empty list.
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) 2001 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.
An example of how to configure the check to use header file
"java.header" and ignore lines 2, 3, and 4 is:
<module name="Header">
<property name="headerFile" value="java.header"/>
<property name="ignoreLines" value="2, 3, 4"/>
</module>