RegexpSingleline

Description

A check for detecting single lines that match a supplied regular expression. Works with any file type.

Rationale: This check can be used to prototype checks and to find common bad practice such as calling ex.printStacktrace(), System.out.println(), System.exit(), etc.

Properties

name description type default value
format illegal pattern regular expression ^$ (empty)
message message which is used to notify about violations, if empty then default(hard-coded) message is used. String ""(empty)
ignoreCase Controls whether to ignore case when searching. Boolean false
minimum The minimum number of matches required in each file. Integer 0
maximum The maximum number of matches required in each file. Integer 0
fileExtensions file type extension of files to process String Set {}

Examples

To configure the check to find trailing whitespace at the end of a line:

<module name="RegexpSingleline">
  <!-- \s matches whitespace character, $ matches end of line. -->
  <property name="format" value="\s+$"/>
</module>
        

To configure the check to find trailing whitespace at the end of a line, with some slack of allowing two occurrences per file:

<module name="RegexpSingleline">
  <property name="format" value="\s+$"/>
  <!-- next line not required as 0 is the default -->
  <property name="minimum" value="0"/>
  <property name="maximum" value="2"/>
</module>
        

An example of how to configure the check to make sure a copyright statement is included in the file:

<module name="RegexpSingleline">
  <property name="format" value="This file is copyrighted"/>
  <property name="minimum" value="1"/>
  <!--  Need to specify a maximum, so 10 times is more than enough. -->
  <property name="maximum" value="10"/>
</module>
        

Package

com.puppycrawl.tools.checkstyle.checks

Parent Module

Checker

RegexpMultiline

Description

A check for detecting that matches across multiple lines. Works with any file type.

Rationale: This check can be used to when the regular expression can be span multiple lines.

Properties

name description type default value
format illegal pattern regular expression ^$ (empty)
message message which is used to notify about violations, if empty then default(hard-coded) message is used. String ""(empty)
ignoreCase Controls whether to ignore case when searching. Boolean false
minimum The minimum number of matches required in each file. Integer 0
maximum The maximum number of matches required in each file. Integer 0
fileExtensions file type extension of files to process String Set {}

Examples

To configure the check to find calls to print to the console:

<module name="RegexpMultiline">
  <property name="format"
   value="System\.(out)|(err)\.print(ln)?\("/>
</module>
        

Package

com.puppycrawl.tools.checkstyle.checks

Parent Module

Checker

RegexpSinglelineJava

Description

This class is variation on RegexpSingleline for detecting single lines that match a supplied regular expression in Java files. It supports suppressing matches in Java comments.

Properties

name description type default value
format illegal pattern regular expression ^$ (empty)
message message which is used to notify about violations, if empty then default(hard-coded) message is used. String ""(empty)
ignoreCase Controls whether to ignore case when searching. Boolean false
minimum The minimum number of matches required in each file. Integer 0
maximum The maximum number of matches required in each file. Integer 0
ignoreComments Controls whether to ignore text in comments when searching. Boolean false

Examples

To configure the check for calls to System.out.println, except in comments:

<module name="RegexpSinglelineJava">
    <!-- . matches any character, so we need to
         escape it and use \. to match dots. -->
  <property name="format" value="System\.out\.println"/>
  <property name="ignoreComments" value="true"/>
</module>
        

To configure the check to find case-insensitive occurrences of "debug":

<module name="RegexpSinglelineJava">
    <property name="format" value="debug"/>
    <property name="ignoreCase" value="true"/>
</module>
        

Package

com.puppycrawl.tools.checkstyle.checks

Parent Module

TreeWalker