src/main/java/com/puppycrawl/tools/checkstyle/XMLLogger.java - platform/external/checkstyle - Git at Google

 ////////////////////////////////////////////////////////////////////////////////
 // checkstyle: Checks Java source code for adherence to a set of rules.
 // Copyright (C) 2001-2017 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;

 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.ResourceBundle;
 import java.util.concurrent.ConcurrentHashMap;

 import com.puppycrawl.tools.checkstyle.api.AuditEvent;
 import com.puppycrawl.tools.checkstyle.api.AuditListener;
 import com.puppycrawl.tools.checkstyle.api.AutomaticBean;
 import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
 import com.puppycrawl.tools.checkstyle.api.SeverityLevel;
 import com.puppycrawl.tools.checkstyle.utils.CommonUtils;

 /**
  * Simple XML logger.
  * It outputs everything in UTF-8 (default XML encoding is UTF-8) in case
  * we want to localize error messages or simply that file names are
  * localized and takes care about escaping as well.

  * @author <a href="mailto:stephane.bailliez@wanadoo.fr">Stephane Bailliez</a>
  */
 // -@cs[AbbreviationAsWordInName] We can not change it as,
 // check's name is part of API (used in configurations).
 public class XMLLogger
     extends AutomaticBean
     implements AuditListener {
     /** Decimal radix. */
     private static final int BASE_10 = 10;

     /** Hex radix. */
     private static final int BASE_16 = 16;

     /** Some known entities to detect. */
     private static final String[] ENTITIES = {"gt", "amp", "lt", "apos",
                                               "quot", };

     /** Close output stream in auditFinished. */
     private final boolean closeStream;

     /** The writer lock object. */
     private final Object writerLock = new Object();

     /** Holds all messages for the given file. */
     private final Map<String, FileMessages> fileMessages =
             new ConcurrentHashMap<>();

     /**
      * Helper writer that allows easy encoding and printing.
      */
     private final PrintWriter writer;

     /**
      * Creates a new {@code XMLLogger} instance.
      * Sets the output to a defined stream.
      * @param outputStream the stream to write logs to.
      * @param closeStream close oS in auditFinished
      * @deprecated in order to fulfill demands of BooleanParameter IDEA check.
      * @noinspection BooleanParameter
      */
     @Deprecated
     public XMLLogger(OutputStream outputStream, boolean closeStream) {
         writer = new PrintWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
         this.closeStream = closeStream;
     }

     /**
      * Creates a new {@code XMLLogger} instance.
      * Sets the output to a defined stream.
      * @param outputStream the stream to write logs to.
      * @param outputStreamOptions if {@code CLOSE} stream should be closed in auditFinished()
      */
     public XMLLogger(OutputStream outputStream, OutputStreamOptions outputStreamOptions) {
         writer = new PrintWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
         closeStream = outputStreamOptions == OutputStreamOptions.CLOSE;
     }

     @Override
     protected void finishLocalSetup() throws CheckstyleException {
         // No code by default
     }

     @Override
     public void auditStarted(AuditEvent event) {
         writer.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");

         final ResourceBundle compilationProperties =
             ResourceBundle.getBundle("checkstylecompilation", Locale.ROOT);
         final String version =
             compilationProperties.getString("checkstyle.compile.version");

         writer.println("<checkstyle version=\"" + version + "\">");
     }

     @Override
     public void auditFinished(AuditEvent event) {
         fileMessages.forEach(this::writeFileMessages);

         writer.println("</checkstyle>");
         if (closeStream) {
             writer.close();
         }
         else {
             writer.flush();
         }
     }

     @Override
     public void fileStarted(AuditEvent event) {
         fileMessages.put(event.getFileName(), new FileMessages());
     }

     @Override
     public void fileFinished(AuditEvent event) {
         final String fileName = event.getFileName();
         final FileMessages messages = fileMessages.get(fileName);

         synchronized (writerLock) {
             writeFileMessages(fileName, messages);
         }

         fileMessages.remove(fileName);
     }

     /**
      * Prints the file section with all file errors and exceptions.
      * @param fileName The file name, as should be printed in the opening file tag.
      * @param messages The file messages.
      */
     private void writeFileMessages(String fileName, FileMessages messages) {
         writeFileOpeningTag(fileName);
         if (messages != null) {
             for (AuditEvent errorEvent : messages.getErrors()) {
                 writeFileError(errorEvent);
             }
             for (Throwable exception : messages.getExceptions()) {
                 writeException(exception);
             }
         }
         writeFileClosingTag();
     }

     /**
      * Prints the "file" opening tag with the given filename.
      * @param fileName The filename to output.
      */
     private void writeFileOpeningTag(String fileName) {
         writer.println("<file name=\"" + encode(fileName) + "\">");
     }

     /**
      * Prints the "file" closing tag.
      */
     private void writeFileClosingTag() {
         writer.println("</file>");
     }

     @Override
     public void addError(AuditEvent event) {
         if (event.getSeverityLevel() != SeverityLevel.IGNORE) {
             final String fileName = event.getFileName();
             if (fileName == null) {
                 synchronized (writerLock) {
                     writeFileError(event);
                 }
             }
             else {
                 final FileMessages messages = fileMessages.computeIfAbsent(
                         fileName, name -> new FileMessages());
                 messages.addError(event);
             }
         }
     }

     /**
      * Outputs the given event to the writer.
      * @param event An event to print.
      */
     private void writeFileError(AuditEvent event) {
         writer.print("<error" + " line=\"" + event.getLine() + "\"");
         if (event.getColumn() > 0) {
             writer.print(" column=\"" + event.getColumn() + "\"");
         }
         writer.print(" severity=\""
                 + event.getSeverityLevel().getName()
                 + "\"");
         writer.print(" message=\""
                 + encode(event.getMessage())
                 + "\"");
         writer.print(" source=\"");
         if (event.getModuleId() == null) {
             writer.print(encode(event.getSourceName()));
         }
         else {
             writer.print(encode(event.getModuleId()));
         }
         writer.println("\"/>");
     }

     @Override
     public void addException(AuditEvent event, Throwable throwable) {
         final String fileName = event.getFileName();
         if (fileName == null) {
             synchronized (writerLock) {
                 writeException(throwable);
             }
         }
         else {
             final FileMessages messages = fileMessages.computeIfAbsent(
                     fileName, name -> new FileMessages());
             messages.addException(throwable);
         }
     }

     /**
      * Writes the exception event to the print writer.
      * @param throwable The
      */
     private void writeException(Throwable throwable) {
         final StringWriter stringWriter = new StringWriter();
         final PrintWriter printer = new PrintWriter(stringWriter);
         printer.println("<exception>");
         printer.println("<![CDATA[");
         throwable.printStackTrace(printer);
         printer.println("]]>");
         printer.println("</exception>");
         writer.println(encode(stringWriter.toString()));
     }

     /**
      * Escape &lt;, &gt; &amp; &#39; and &quot; as their entities.
      * @param value the value to escape.
      * @return the escaped value if necessary.
      */
     public static String encode(String value) {
         final StringBuilder sb = new StringBuilder(256);
         for (int i = 0; i < value.length(); i++) {
             final char chr = value.charAt(i);
             switch (chr) {
                 case '<':
                     sb.append("&lt;");
                     break;
                 case '>':
                     sb.append("&gt;");
                     break;
                 case '\'':
                     sb.append("&apos;");
                     break;
                 case '\"':
                     sb.append("&quot;");
                     break;
                 case '&':
                     sb.append("&amp;");
                     break;
                 case '\r':
                     break;
                 case '\n':
                     sb.append("&#10;");
                     break;
                 default:
                     if (Character.isISOControl(chr)) {
                         // true escape characters need '&' before but it also requires XML 1.1
                         // until https://github.com/checkstyle/checkstyle/issues/5168
                         sb.append("#x");
                         sb.append(Integer.toHexString(chr));
                         sb.append(';');
                     }
                     else {
                         sb.append(chr);
                     }
                     break;
             }
         }
         return sb.toString();
     }

     /**
      * Finds whether the given argument is character or entity reference.
      * @param ent the possible entity to look for.
      * @return whether the given argument a character or entity reference
      */
     public static boolean isReference(String ent) {
         boolean reference = false;

         if (ent.charAt(0) != '&' || !CommonUtils.endsWithChar(ent, ';')) {
             reference = false;
         }
         else if (ent.charAt(1) == '#') {
             // prefix is "&#"
             int prefixLength = 2;

             int radix = BASE_10;
             if (ent.charAt(2) == 'x') {
                 prefixLength++;
                 radix = BASE_16;
             }
             try {
                 Integer.parseInt(
                     ent.substring(prefixLength, ent.length() - 1), radix);
                 reference = true;
             }
             catch (final NumberFormatException ignored) {
                 reference = false;
             }
         }
         else {
             final String name = ent.substring(1, ent.length() - 1);
             for (String element : ENTITIES) {
                 if (name.equals(element)) {
                     reference = true;
                     break;
                 }
             }
         }
         return reference;
     }

     /**
      * The registered file messages.
      */
     private static class FileMessages {
         /** The file error events. */
         private final List<AuditEvent> errors = Collections.synchronizedList(new ArrayList<>());

         /** The file exceptions. */
         private final List<Throwable> exceptions = Collections.synchronizedList(new ArrayList<>());

         /**
          * Returns the file error events.
          * @return the file error events.
          */
         public List<AuditEvent> getErrors() {
             return Collections.unmodifiableList(errors);
         }

         /**
          * Adds the given error event to the messages.
          * @param event the error event.
          */
         public void addError(AuditEvent event) {
             errors.add(event);
         }

         /**
          * Returns the file exceptions.
          * @return the file exceptions.
          */
         public List<Throwable> getExceptions() {
             return Collections.unmodifiableList(exceptions);
         }

         /**
          * Adds the given exception to the messages.
          * @param throwable the file exception
          */
         public void addException(Throwable throwable) {
             exceptions.add(throwable);
         }
     }
 }
	////////////////////////////////////////////////////////////////////////////////
	// checkstyle: Checks Java source code for adherence to a set of rules.
	// Copyright (C) 2001-2017 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;

	import java.io.OutputStream;
	import java.io.OutputStreamWriter;
	import java.io.PrintWriter;
	import java.io.StringWriter;
	import java.nio.charset.StandardCharsets;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.List;
	import java.util.Locale;
	import java.util.Map;
	import java.util.ResourceBundle;
	import java.util.concurrent.ConcurrentHashMap;

	import com.puppycrawl.tools.checkstyle.api.AuditEvent;
	import com.puppycrawl.tools.checkstyle.api.AuditListener;
	import com.puppycrawl.tools.checkstyle.api.AutomaticBean;
	import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
	import com.puppycrawl.tools.checkstyle.api.SeverityLevel;
	import com.puppycrawl.tools.checkstyle.utils.CommonUtils;

	/**
	* Simple XML logger.
	* It outputs everything in UTF-8 (default XML encoding is UTF-8) in case
	* we want to localize error messages or simply that file names are
	* localized and takes care about escaping as well.

	* @author <a href="mailto:stephane.bailliez@wanadoo.fr">Stephane Bailliez</a>
	*/
	// -@cs[AbbreviationAsWordInName] We can not change it as,
	// check's name is part of API (used in configurations).
	public class XMLLogger
	extends AutomaticBean
	implements AuditListener {
	/** Decimal radix. */
	private static final int BASE_10 = 10;

	/** Hex radix. */
	private static final int BASE_16 = 16;

	/** Some known entities to detect. */
	private static final String[] ENTITIES = {"gt", "amp", "lt", "apos",
	"quot", };

	/** Close output stream in auditFinished. */
	private final boolean closeStream;

	/** The writer lock object. */
	private final Object writerLock = new Object();

	/** Holds all messages for the given file. */
	private final Map<String, FileMessages> fileMessages =
	new ConcurrentHashMap<>();

	/**
	* Helper writer that allows easy encoding and printing.
	*/
	private final PrintWriter writer;

	/**
	* Creates a new {@code XMLLogger} instance.
	* Sets the output to a defined stream.
	* @param outputStream the stream to write logs to.
	* @param closeStream close oS in auditFinished
	* @deprecated in order to fulfill demands of BooleanParameter IDEA check.
	* @noinspection BooleanParameter
	*/
	@Deprecated
	public XMLLogger(OutputStream outputStream, boolean closeStream) {
	writer = new PrintWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
	this.closeStream = closeStream;
	}

	/**
	* Creates a new {@code XMLLogger} instance.
	* Sets the output to a defined stream.
	* @param outputStream the stream to write logs to.
	* @param outputStreamOptions if {@code CLOSE} stream should be closed in auditFinished()
	*/
	public XMLLogger(OutputStream outputStream, OutputStreamOptions outputStreamOptions) {
	writer = new PrintWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
	closeStream = outputStreamOptions == OutputStreamOptions.CLOSE;
	}

	@Override
	protected void finishLocalSetup() throws CheckstyleException {
	// No code by default
	}

	@Override
	public void auditStarted(AuditEvent event) {
	writer.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");

	final ResourceBundle compilationProperties =
	ResourceBundle.getBundle("checkstylecompilation", Locale.ROOT);
	final String version =
	compilationProperties.getString("checkstyle.compile.version");

	writer.println("<checkstyle version=\"" + version + "\">");
	}

	@Override
	public void auditFinished(AuditEvent event) {
	fileMessages.forEach(this::writeFileMessages);

	writer.println("</checkstyle>");
	if (closeStream) {
	writer.close();
	}
	else {
	writer.flush();
	}
	}

	@Override
	public void fileStarted(AuditEvent event) {
	fileMessages.put(event.getFileName(), new FileMessages());
	}

	@Override
	public void fileFinished(AuditEvent event) {
	final String fileName = event.getFileName();
	final FileMessages messages = fileMessages.get(fileName);

	synchronized (writerLock) {
	writeFileMessages(fileName, messages);
	}

	fileMessages.remove(fileName);
	}

	/**
	* Prints the file section with all file errors and exceptions.
	* @param fileName The file name, as should be printed in the opening file tag.
	* @param messages The file messages.
	*/
	private void writeFileMessages(String fileName, FileMessages messages) {
	writeFileOpeningTag(fileName);
	if (messages != null) {
	for (AuditEvent errorEvent : messages.getErrors()) {
	writeFileError(errorEvent);
	}
	for (Throwable exception : messages.getExceptions()) {
	writeException(exception);
	}
	}
	writeFileClosingTag();
	}

	/**
	* Prints the "file" opening tag with the given filename.
	* @param fileName The filename to output.
	*/
	private void writeFileOpeningTag(String fileName) {
	writer.println("<file name=\"" + encode(fileName) + "\">");
	}

	/**
	* Prints the "file" closing tag.
	*/
	private void writeFileClosingTag() {
	writer.println("</file>");
	}

	@Override
	public void addError(AuditEvent event) {
	if (event.getSeverityLevel() != SeverityLevel.IGNORE) {
	final String fileName = event.getFileName();
	if (fileName == null) {
	synchronized (writerLock) {
	writeFileError(event);
	}
	}
	else {
	final FileMessages messages = fileMessages.computeIfAbsent(
	fileName, name -> new FileMessages());
	messages.addError(event);
	}
	}
	}

	/**
	* Outputs the given event to the writer.
	* @param event An event to print.
	*/
	private void writeFileError(AuditEvent event) {
	writer.print("<error" + " line=\"" + event.getLine() + "\"");
	if (event.getColumn() > 0) {
	writer.print(" column=\"" + event.getColumn() + "\"");
	}
	writer.print(" severity=\""
	+ event.getSeverityLevel().getName()
	+ "\"");
	writer.print(" message=\""
	+ encode(event.getMessage())
	+ "\"");
	writer.print(" source=\"");
	if (event.getModuleId() == null) {
	writer.print(encode(event.getSourceName()));
	}
	else {
	writer.print(encode(event.getModuleId()));
	}
	writer.println("\"/>");
	}

	@Override
	public void addException(AuditEvent event, Throwable throwable) {
	final String fileName = event.getFileName();
	if (fileName == null) {
	synchronized (writerLock) {
	writeException(throwable);
	}
	}
	else {
	final FileMessages messages = fileMessages.computeIfAbsent(
	fileName, name -> new FileMessages());
	messages.addException(throwable);
	}
	}

	/**
	* Writes the exception event to the print writer.
	* @param throwable The
	*/
	private void writeException(Throwable throwable) {
	final StringWriter stringWriter = new StringWriter();
	final PrintWriter printer = new PrintWriter(stringWriter);
	printer.println("<exception>");
	printer.println("<![CDATA[");
	throwable.printStackTrace(printer);
	printer.println("]]>");
	printer.println("</exception>");
	writer.println(encode(stringWriter.toString()));
	}

	/**
	* Escape <, > & ' and " as their entities.
	* @param value the value to escape.
	* @return the escaped value if necessary.
	*/
	public static String encode(String value) {
	final StringBuilder sb = new StringBuilder(256);
	for (int i = 0; i < value.length(); i++) {
	final char chr = value.charAt(i);
	switch (chr) {
	case '<':
	sb.append("<");
	break;
	case '>':
	sb.append(">");
	break;
	case '\'':
	sb.append("'");
	break;
	case '\"':
	sb.append(""");
	break;
	case '&':
	sb.append("&");
	break;
	case '\r':
	break;
	case '\n':
	sb.append(" ");
	break;
	default:
	if (Character.isISOControl(chr)) {
	// true escape characters need '&' before but it also requires XML 1.1
	// until https://github.com/checkstyle/checkstyle/issues/5168
	sb.append("#x");
	sb.append(Integer.toHexString(chr));
	sb.append(';');
	}
	else {
	sb.append(chr);
	}
	break;
	}
	}
	return sb.toString();
	}

	/**
	* Finds whether the given argument is character or entity reference.
	* @param ent the possible entity to look for.
	* @return whether the given argument a character or entity reference
	*/
	public static boolean isReference(String ent) {
	boolean reference = false;

	if (ent.charAt(0) != '&' \|\| !CommonUtils.endsWithChar(ent, ';')) {
	reference = false;
	}
	else if (ent.charAt(1) == '#') {
	// prefix is "&#"
	int prefixLength = 2;

	int radix = BASE_10;
	if (ent.charAt(2) == 'x') {
	prefixLength++;
	radix = BASE_16;
	}
	try {
	Integer.parseInt(
	ent.substring(prefixLength, ent.length() - 1), radix);
	reference = true;
	}
	catch (final NumberFormatException ignored) {
	reference = false;
	}
	}
	else {
	final String name = ent.substring(1, ent.length() - 1);
	for (String element : ENTITIES) {
	if (name.equals(element)) {
	reference = true;
	break;
	}
	}
	}
	return reference;
	}

	/**
	* The registered file messages.
	*/
	private static class FileMessages {
	/** The file error events. */
	private final List<AuditEvent> errors = Collections.synchronizedList(new ArrayList<>());

	/** The file exceptions. */
	private final List<Throwable> exceptions = Collections.synchronizedList(new ArrayList<>());

	/**
	* Returns the file error events.
	* @return the file error events.
	*/
	public List<AuditEvent> getErrors() {
	return Collections.unmodifiableList(errors);
	}

	/**
	* Adds the given error event to the messages.
	* @param event the error event.
	*/
	public void addError(AuditEvent event) {
	errors.add(event);
	}

	/**
	* Returns the file exceptions.
	* @return the file exceptions.
	*/
	public List<Throwable> getExceptions() {
	return Collections.unmodifiableList(exceptions);
	}

	/**
	* Adds the given exception to the messages.
	* @param throwable the file exception
	*/
	public void addException(Throwable throwable) {
	exceptions.add(throwable);
	}
	}
	}