RegexpSinglelineJavaCheck.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 com.puppycrawl.tools.checkstyle.StatelessCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
/**
* <p>
* Checks that a specified pattern matches a single line in Java files.
* </p>
* <p>
* This class is variation on
* <a href="https://checkstyle.org/config_regexp.html#RegexpSingleline">RegexpSingleline</a>
* for detecting single lines that match a supplied regular expression in Java files.
* It supports suppressing matches in Java comments.
* </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 ignoreComments} - Control whether to ignore text in comments when searching.
* Type is {@code boolean}.
* Default value is {@code false}.
* </li>
* </ul>
* <p>
* To configure the default check:
* </p>
* <pre>
* <module name="RegexpSinglelineJava"/>
* </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 for calls to {@code System.out.println}, except in comments:
* </p>
* <pre>
* <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>
* </pre>
* <p>Example:</p>
* <pre>
* System.out.println(""); // violation, instruction matches illegal pattern
* System.out.
* println(""); // OK
* /* System.out.println */ // OK, comments are ignored
* </pre>
* <p>
* To configure the check to find case-insensitive occurrences of "debug":
* </p>
* <pre>
* <module name="RegexpSinglelineJava">
* <property name="format" value="debug"/>
* <property name="ignoreCase" value="true"/>
* </module>
* </pre>
* <p>Example:</p>
* <pre>
* int debug = 0; // violation, variable name matches illegal pattern
* public class Debug { // violation, class name matches illegal pattern
* /* this is for de
* bug only; */ // OK
* </pre>
* <p>
* To configure the check to find occurrences of
* "\.read(.*)|\.write(.*)"
* and display "IO found" for each violation.
* </p>
* <pre>
* <module name="RegexpSinglelineJava">
* <property name="format" value="\.read(.*)|\.write(.*)"/>
* <property name="message" value="IO found"/>
* </module>
* </pre>
* <p>Example:</p>
* <pre>
* FileReader in = new FileReader("path/to/input");
* int ch = in.read(); // violation
* while(ch != -1) {
* System.out.print((char)ch);
* ch = in.read(); // violation
* }
*
* FileWriter out = new FileWriter("path/to/output");
* out.write("something"); // violation
* </pre>
* <p>
* To configure the check to find occurrences of
* "\.log(.*)". We want to allow a maximum of 2 occurrences.
* </p>
* <pre>
* <module name="RegexpSinglelineJava">
* <property name="format" value="\.log(.*)"/>
* <property name="maximum" value="2"/>
* </module>
* </pre>
* <p>Example:</p>
* <pre>
* public class Foo{
* public void bar(){
* Logger.log("first"); // OK, first occurrence is allowed
* Logger.log("second"); // OK, second occurrence is allowed
* Logger.log("third"); // violation
* System.out.println("fourth");
* Logger.log("fifth"); // violation
* }
* }
* </pre>
* <p>
* To configure the check to find all occurrences of
* "public". We want to ignore comments,
* display "public member found" for each violation
* and say if less than 2 occurrences.
* </p>
* <pre>
* <module name="RegexpSinglelineJava">
* <property name="format" value="public"/>
* <property name="minimum" value="2"/>
* <property name="message" value="public member found"/>
* <property name="ignoreComments" value="true"/>
* </module>
* </pre>
* <p>Example:</p>
* <pre>
* class Foo{ // violation, file contains less than 2 occurrences of "public"
* private int a;
* /* public comment */ // OK, comment is ignored
* private void bar1() {}
* public void bar2() {} // violation
* }
* </pre>
* <p>Example:</p>
* <pre>
* class Foo{
* private int a;
* /* public comment */ // OK, comment is ignored
* public void bar1() {} // violation
* public void bar2() {} // violation
* }
* </pre>
* <p>
* Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
* </p>
* <p>
* Violation Message Keys:
* </p>
* <ul>
* <li>
* {@code regexp.exceeded}
* </li>
* <li>
* {@code regexp.minimum}
* </li>
* </ul>
*
* @since 6.0
*/
@StatelessCheck
public class RegexpSinglelineJavaCheck extends AbstractCheck {
/** 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;
/** Control whether to ignore text in comments when searching. */
private boolean ignoreComments;
@Override
public int[] getDefaultTokens() {
return getRequiredTokens();
}
@Override
public int[] getAcceptableTokens() {
return getRequiredTokens();
}
@Override
public int[] getRequiredTokens() {
return CommonUtil.EMPTY_INT_ARRAY;
}
@Override
public void beginTree(DetailAST rootAST) {
MatchSuppressor suppressor = null;
if (ignoreComments) {
suppressor = new CommentSuppressor(getFileContents());
}
final DetectorOptions options = DetectorOptions.newBuilder()
.reporter(this)
.compileFlags(0)
.suppressor(suppressor)
.format(format)
.message(message)
.minimum(minimum)
.maximum(maximum)
.ignoreCase(ignoreCase)
.build();
final SinglelineDetector detector = new SinglelineDetector(options);
detector.processLines(getFileContents().getText());
}
/**
* 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;
}
/**
* Setter to control whether to ignore text in comments when searching.
*
* @param ignore whether to ignore text in comments when searching.
*/
public void setIgnoreComments(boolean ignore) {
ignoreComments = ignore;
}
}