XMLLogger.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;
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.Map;
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.SeverityLevel;
import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
/**
* 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.
*/
// -@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 outputStreamOptions if {@code CLOSE} stream should be closed in auditFinished()
* @throws IllegalArgumentException if outputStreamOptions is null.
*/
public XMLLogger(OutputStream outputStream, OutputStreamOptions outputStreamOptions) {
writer = new PrintWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
if (outputStreamOptions == null) {
throw new IllegalArgumentException("Parameter outputStreamOptions can not be null");
}
closeStream = outputStreamOptions == OutputStreamOptions.CLOSE;
}
@Override
protected void finishLocalSetup() {
// No code by default
}
@Override
public void auditStarted(AuditEvent event) {
writer.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
final String version = XMLLogger.class.getPackage().getImplementationVersion();
writer.println("<checkstyle version=\"" + version + "\">");
}
@Override
public void auditFinished(AuditEvent event) {
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 || !fileMessages.containsKey(fileName)) {
synchronized (writerLock) {
writeFileError(event);
}
}
else {
final FileMessages messages = fileMessages.get(fileName);
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 || !fileMessages.containsKey(fileName)) {
synchronized (writerLock) {
writeException(throwable);
}
}
else {
final FileMessages messages = fileMessages.get(fileName);
messages.addException(throwable);
}
}
/**
* Writes the exception event to the print writer.
*
* @param throwable The
*/
private void writeException(Throwable throwable) {
writer.println("<exception>");
writer.println("<![CDATA[");
final StringWriter stringWriter = new StringWriter();
final PrintWriter printer = new PrintWriter(stringWriter);
throwable.printStackTrace(printer);
writer.println(encode(stringWriter.toString()));
writer.println("]]>");
writer.println("</exception>");
}
/**
* 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) == '&' && CommonUtil.endsWithChar(ent, ';')) {
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);
}
}
}