/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache license, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the license for the specific language governing permissions and
* limitations under the license.
*/
package org.apache.logging.log4j.core.layout;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginFactory;
import org.apache.logging.log4j.core.helpers.Charsets;
import org.apache.logging.log4j.core.helpers.Throwables;
import org.apache.logging.log4j.core.helpers.Transform;
import org.apache.logging.log4j.message.Message;
import org.apache.logging.log4j.message.MultiformatMessage;
/**
* Appends a series of JSON events as strings serialized as bytes.
*
* <h4>Complete well-formed JSON vs. fragment JSON</h4>
* <p>
* If you configure {@code complete="true"}, the appender outputs a well-formed JSON document.
* By default, with {@code complete="false"}, you should include the
* output as an <em>external file</em> in a separate file to form a well-formed JSON document.
* </p>
* <p>
* A well-formed JSON document follows this pattern:
* </p>
*
* <pre>[
* {
* "logger":"com.foo.Bar",
* "timestamp":"1376681196470",
* "level":"INFO",
* "thread":"main",
* "message":"Message flushed with immediate flush=true"
* },
* {
* "logger":"com.foo.Bar",
* "timestamp":"1376681196471",
* "level":"ERROR",
* "thread":"main",
* "message":"Message flushed with immediate flush=true",
* "throwable":"java.lang.IllegalArgumentException: badarg\\n\\tat org.apache.logging.log4j.core.appender.JSONCompleteFileAppenderTest.testFlushAtEndOfBatch(JSONCompleteFileAppenderTest.java:54)\\n\\tat sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\\n\\tat sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)\\n\\tat sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\\n\\tat java.lang.reflect.Method.invoke(Method.java:606)\\n\\tat org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)\\n\\tat org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)\\n\\tat org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)\\n\\tat org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)\\n\\tat org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)\\n\\tat org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)\\n\\tat org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)\\n\\tat org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)\\n\\tat org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)\\n\\tat org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)\\n\\tat org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)\\n\\tat org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)\\n\\tat org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)\\n\\tat org.junit.runners.ParentRunner.run(ParentRunner.java:309)\\n\\tat org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)\\n\\tat org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)\\n\\tat org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)\\n\\tat org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)\\n\\tat org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)\\n\\tat org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)\\n"
* }
* ]</pre>
* <p>
* If {@code complete="false"}, the appender does not write the JSON open array character "[" at the start of the document.
* and "]" and the end.
* </p>
* <p>
* This approach enforces the independence of the JSONLayout and the appender where you embed it.
* </p>
* <h4>Encoding</h4>
* <p>
* Appenders using this layout should have their {@code charset} set to {@code UTF-8} or {@code UTF-16}, otherwise
* events containing non ASCII characters could result in corrupted log files.
* </p>
* <h4>Pretty vs. compact XML</h4>
* <p>
* By default, the JSON layout is not compact (a.k.a. not "pretty") with {@code compact="false"}, which means the
* appender uses end-of-line characters and indents lines to format the text. If {@code compact="true"}, then no
* end-of-line or indentation is used. Message content may contain, of course, escaped end-of-lines.
* </p>
*/
@Plugin(name = "JSONLayout", category = "Core", elementType = "layout", printObject = true)
public class JSONLayout extends AbstractStringLayout {
private static final int DEFAULT_SIZE = 256;
// We yield to \r\n for the default.
private static final String DEFAULT_EOL = "\r\n";
private static final String COMPACT_EOL = "";
private static final String DEFAULT_INDENT = " ";
private static final String COMPACT_INDENT = "";
private static final String[] FORMATS = new String[] { "json" };
private final boolean locationInfo;
private final boolean properties;
private final boolean complete;
private final String eol;
private final String indent1;
private final String indent2;
private final String indent3;
private final String indent4;
private volatile boolean firstLayoutDone;
protected JSONLayout(final boolean locationInfo, final boolean properties, final boolean complete, boolean compact,
final Charset charset) {
super(charset);
this.locationInfo = locationInfo;
this.properties = properties;
this.complete = complete;
this.eol = compact ? COMPACT_EOL : DEFAULT_EOL;
this.indent1 = compact ? COMPACT_INDENT : DEFAULT_INDENT;
this.indent2 = this.indent1 + this.indent1;
this.indent3 = this.indent2 + this.indent1;
this.indent4 = this.indent3 + this.indent1;
}
/**
* Formats a {@link org.apache.logging.log4j.core.LogEvent} in conformance with the log4j.dtd.
*
* @param event
* The LogEvent.
* @return The XML representation of the LogEvent.
*/
@Override
public String toSerializable(final LogEvent event) {
final StringBuilder buf = new StringBuilder(DEFAULT_SIZE);
// DC locking to avoid synchronizing the whole layout.
boolean check = this.firstLayoutDone;
if (!this.firstLayoutDone) {
synchronized(this) {
check = this.firstLayoutDone;
if (!check) {
this.firstLayoutDone = true;
} else {
buf.append(',');
buf.append(this.eol);
}
}
} else {
buf.append(',');
buf.append(this.eol);
}
buf.append(this.indent1);
buf.append('{');
buf.append(this.eol);
buf.append(this.indent2);
buf.append("\"logger\":\"");
String name = event.getLoggerName();
if (name.isEmpty()) {
name = "root";
}
buf.append(Transform.escapeJsonControlCharacters(name));
buf.append("\",");
buf.append(this.eol);
buf.append(this.indent2);
buf.append("\"timestamp\":\"");
buf.append(event.getMillis());
buf.append("\",");
buf.append(this.eol);
buf.append(this.indent2);
buf.append("\"level\":\"");
buf.append(Transform.escapeJsonControlCharacters(String.valueOf(event.getLevel())));
buf.append("\",");
buf.append(this.eol);
buf.append(this.indent2);
buf.append("\"thread\":\"");
buf.append(Transform.escapeJsonControlCharacters(event.getThreadName()));
buf.append("\",");
buf.append(this.eol);
final Message msg = event.getMessage();
if (msg != null) {
boolean jsonSupported = false;
if (msg instanceof MultiformatMessage) {
final String[] formats = ((MultiformatMessage) msg).getFormats();
for (final String format : formats) {
if (format.equalsIgnoreCase("JSON")) {
jsonSupported = true;
break;
}
}
}
buf.append(this.indent2);
buf.append("\"message\":\"");
if (jsonSupported) {
buf.append(((MultiformatMessage) msg).getFormattedMessage(FORMATS));
} else {
Transform.appendEscapingCDATA(buf, event.getMessage().getFormattedMessage());
}
buf.append('\"');
}
if (event.getContextStack().getDepth() > 0) {
buf.append(",");
buf.append(this.eol);
buf.append("\"ndc\":");
Transform.appendEscapingCDATA(buf, event.getContextStack().toString());
buf.append("\"");
}
final Throwable throwable = event.getThrown();
if (throwable != null) {
buf.append(",");
buf.append(this.eol);
buf.append(this.indent2);
buf.append("\"throwable\":\"");
final List<String> list = Throwables.toStringList(throwable);
for (final String str : list) {
buf.append(Transform.escapeJsonControlCharacters(str));
buf.append("\\\\n");
}
buf.append("\"");
}
if (this.locationInfo) {
final StackTraceElement element = event.getSource();
buf.append(",");
buf.append(this.eol);
buf.append(this.indent2);
buf.append("\"LocationInfo\":{");
buf.append(this.eol);
buf.append(this.indent3);
buf.append("\"class\":\"");
buf.append(Transform.escapeJsonControlCharacters(element.getClassName()));
buf.append("\",");
buf.append(this.eol);
buf.append(this.indent3);
buf.append("\"method\":\"");
buf.append(Transform.escapeJsonControlCharacters(element.getMethodName()));
buf.append("\",");
buf.append(this.eol);
buf.append(this.indent3);
buf.append("\"file\":\"");
buf.append(Transform.escapeJsonControlCharacters(element.getFileName()));
buf.append("\",");
buf.append(this.eol);
buf.append(this.indent3);
buf.append("\"line\":\"");
buf.append(element.getLineNumber());
buf.append("\"");
buf.append(this.eol);
buf.append(this.indent2);
buf.append("}");
}
if (this.properties && event.getContextMap().size() > 0) {
buf.append(",");
buf.append(this.eol);
buf.append(this.indent2);
buf.append("\"Properties\":[");
buf.append(this.eol);
final Set<Entry<String, String>> entrySet = event.getContextMap().entrySet();
int i = 1;
for (final Map.Entry<String, String> entry : entrySet) {
buf.append(this.indent3);
buf.append('{');
buf.append(this.eol);
buf.append(this.indent4);
buf.append("\"name\":\"");
buf.append(Transform.escapeJsonControlCharacters(entry.getKey()));
buf.append("\",");
buf.append(this.eol);
buf.append(this.indent4);
buf.append("\"value\":\"");
buf.append(Transform.escapeJsonControlCharacters(String.valueOf(entry.getValue())));
buf.append("\"");
buf.append(this.eol);
buf.append(this.indent3);
buf.append("}");
if (i < entrySet.size()) {
buf.append(",");
}
buf.append(this.eol);
i++;
}
buf.append(this.indent2);
buf.append("]");
}
buf.append(this.eol);
buf.append(this.indent1);
buf.append("}");
return buf.toString();
}
/**
* Returns appropriate JSON headers.
*
* @return a byte array containing the header, opening the JSON array.
*/
@Override
public byte[] getHeader() {
if (!this.complete) {
return null;
}
final StringBuilder buf = new StringBuilder();
buf.append('[');
buf.append(this.eol);
return buf.toString().getBytes(this.getCharset());
}
/**
* Returns appropriate JSON footer.
*
* @return a byte array containing the footer, closing the JSON array.
*/
@Override
public byte[] getFooter() {
if (!this.complete) {
return null;
}
return (this.eol + "]" + this.eol).getBytes(this.getCharset());
}
/**
* XMLLayout's content format is specified by:
* <p/>
* Key: "dtd" Value: "log4j-events.dtd"
* <p/>
* Key: "version" Value: "2.0"
*
* @return Map of content format keys supporting XMLLayout
*/
@Override
public Map<String, String> getContentFormat() {
final Map<String, String> result = new HashMap<String, String>();
result.put("version", "2.0");
return result;
}
@Override
/**
* @return The content type.
*/
public String getContentType() {
return "application/json; charset=" + this.getCharset();
}
/**
* Creates an XML Layout.
*
* @param locationInfo
* If "true", includes the location information in the generated JSON.
* @param properties
* If "true", includes the thread context in the generated JSON.
* @param completeStr
* If "true", includes the JSON header and footer, defaults to "false".
* @param compactStr
* If "true", does not use end-of-lines and indentation, defaults to "false".
* @param charsetName
* The character set to use, if {@code null}, uses "UTF-8".
* @return An XML Layout.
*/
@PluginFactory
public static JSONLayout createLayout(
@PluginAttribute("locationInfo") final String locationInfo,
@PluginAttribute("properties") final String properties,
@PluginAttribute("complete") final String completeStr,
@PluginAttribute("compact") final String compactStr,
@PluginAttribute("charset") final String charsetName) {
final Charset charset = Charsets.getSupportedCharset(charsetName, Charsets.UTF_8);
final boolean info = Boolean.parseBoolean(locationInfo);
final boolean props = Boolean.parseBoolean(properties);
final boolean complete = Boolean.parseBoolean(completeStr);
final boolean compact = Boolean.parseBoolean(compactStr);
return new JSONLayout(info, props, complete, compact, charset);
}
}