RegexpSinglelineCheck.java
////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2021 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.regexp;
import java.io.File;
import com.puppycrawl.tools.checkstyle.StatelessCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
import com.puppycrawl.tools.checkstyle.api.FileText;
/**
* <p>
* Checks that a specified pattern matches a single line in any file type.
* </p>
* <p>
* Rationale: This check can be used to prototype checks and to find common bad
* practice such as calling {@code ex.printStacktrace()},
* {@code System.out.println()}, {@code System.exit()}, etc.
* </p>
* <ul>
* <li>
* Property {@code format} - Specify the format of the regular expression to match.
* Type is {@code java.lang.String}.
* Default value is {@code "$."}.
* </li>
* <li>
* Property {@code message} - Specify the message which is used to notify about
* violations, if empty then default (hard-coded) message is used.
* Type is {@code java.lang.String}.
* Default value is {@code null}.
* </li>
* <li>
* Property {@code ignoreCase} - Control whether to ignore case when searching.
* Type is {@code boolean}.
* Default value is {@code false}.
* </li>
* <li>
* Property {@code minimum} - Specify the minimum number of matches required in each file.
* Type is {@code int}.
* Default value is {@code 0}.
* </li>
* <li>
* Property {@code maximum} - Specify the maximum number of matches required in each file.
* Type is {@code int}.
* Default value is {@code 0}.
* </li>
* <li>
* Property {@code fileExtensions} - Specify the file type extension of files to process.
* Type is {@code java.lang.String[]}.
* Default value is {@code ""}.
* </li>
* </ul>
* <p>
* To configure the default check:
* </p>
* <pre>
* <module name="RegexpSingleline" />
* </pre>
* <p>
* This configuration does not match to anything,
* so we do not provide any code example for it
* as no violation will ever be reported.
* </p>
* <p>
* To configure the check to find occurrences of 'System.exit('
* with some <i>slack</i> of allowing only one occurrence per file:
* </p>
* <pre>
* <module name="RegexpSingleline">
* <property name="format" value="System.exit\("/>
* <!-- next line not required as 0 is the default -->
* <property name="minimum" value="0"/>
* <property name="maximum" value="1"/>
* </module>
* </pre>
* <p>Example:</p>
* <pre>
* class MyClass {
* void myFunction() {
* try {
* doSomething();
* } catch (Exception e) {
* System.exit(1); // OK, as only there is only one occurrence.
* }
* }
* void doSomething(){};
* }
* </pre>
* <pre>
* class MyClass {
* void myFunction() {
* try {
* doSomething();
* System.exit(0);
* } catch (Exception e) {
* System.exit(1); // Violation, as there are more than one occurrence.
* }
* }
* void doSomething(){};
* }
* </pre>
* <p>
* An example of how to configure the check to make sure a copyright statement
* is included in the file:
* </p>
* <pre>
* <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>
* </pre>
* <p>Example:</p>
* <pre>
* /**
* * This file is copyrighted under CC. // Ok, as the file contains a copyright statement.
* */
* class MyClass {
*
* }
* </pre>
* <pre>
* /** // violation, as the file doesn't contain a copyright statement.
* * MyClass as a configuration example.
* */
* class MyClass {
*
* }
* </pre>
* <p>
* An example of how to configure the check to make sure sql files contains the term 'license'.
* </p>
* <pre>
* <module name="RegexpSingleline">
* <property name="format" value="license"/>
* <property name="minimum" value="1"/>
* <property name="maximum" value="9999"/>
* <property name="ignoreCase" value="true"/>
* <!-- Configure a message to be shown on violation of the Check. -->
* <property name="message"
* value="File must contain at least one occurrence of 'license' term"/>
* <!-- Perform the Check only on files with java extension. -->
* <property name="fileExtensions" value="sql"/>
* </module>
* </pre>
* <p>Example:</p>
* <pre>
* /*
* AP 2.0 License. // Ok, Check ignores the case of the term.
* */
* CREATE DATABASE MyDB;
* </pre>
* <pre>
* /* // violation, file doesn't contain the term.
* Example sql file.
* */
* CREATE DATABASE MyDB;
* </pre>
* <p>
* Parent is {@code com.puppycrawl.tools.checkstyle.Checker}
* </p>
* <p>
* Violation Message Keys:
* </p>
* <ul>
* <li>
* {@code regexp.exceeded}
* </li>
* <li>
* {@code regexp.minimum}
* </li>
* </ul>
*
* @since 5.0
*/
@StatelessCheck
public class RegexpSinglelineCheck extends AbstractFileSetCheck {
/** Specify the format of the regular expression to match. */
private String format = "$.";
/**
* Specify the message which is used to notify about violations,
* if empty then default (hard-coded) message is used.
*/
private String message;
/** Specify the minimum number of matches required in each file. */
private int minimum;
/** Specify the maximum number of matches required in each file. */
private int maximum;
/** Control whether to ignore case when searching. */
private boolean ignoreCase;
/** The detector to use. */
private SinglelineDetector detector;
@Override
public void beginProcessing(String charset) {
final DetectorOptions options = DetectorOptions.newBuilder()
.reporter(this)
.compileFlags(0)
.format(format)
.message(message)
.minimum(minimum)
.maximum(maximum)
.ignoreCase(ignoreCase)
.build();
detector = new SinglelineDetector(options);
}
@Override
protected void processFiltered(File file, FileText fileText) {
detector.processLines(fileText);
}
/**
* Setter to specify the format of the regular expression to match.
*
* @param format the format of the regular expression to match.
*/
public void setFormat(String format) {
this.format = format;
}
/**
* Setter to specify the message which is used to notify about violations,
* if empty then default (hard-coded) message is used.
*
* @param message the message to report for a match.
*/
public void setMessage(String message) {
this.message = message;
}
/**
* Setter to specify the minimum number of matches required in each file.
*
* @param minimum the minimum number of matches required in each file.
*/
public void setMinimum(int minimum) {
this.minimum = minimum;
}
/**
* Setter to specify the maximum number of matches required in each file.
*
* @param maximum the maximum number of matches required in each file.
*/
public void setMaximum(int maximum) {
this.maximum = maximum;
}
/**
* Setter to control whether to ignore case when searching.
*
* @param ignoreCase whether to ignore case when searching.
*/
public void setIgnoreCase(boolean ignoreCase) {
this.ignoreCase = ignoreCase;
}
}