log4j-core/src/main/java/org/apache/logging/log4j/core/layout/GelfLayout.java - logging-log4j2 - Git at Google

 /*
  * 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 org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.core.Layout;
 import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.config.Configuration;
 import org.apache.logging.log4j.core.layout.internal.ExcludeChecker;
 import org.apache.logging.log4j.core.layout.internal.IncludeChecker;
 import org.apache.logging.log4j.core.layout.internal.ListChecker;
 import org.apache.logging.log4j.core.lookup.StrSubstitutor;
 import org.apache.logging.log4j.core.net.Severity;
 import org.apache.logging.log4j.core.util.JsonUtils;
 import org.apache.logging.log4j.core.util.KeyValuePair;
 import org.apache.logging.log4j.core.util.NetUtils;
 import org.apache.logging.log4j.core.util.Patterns;
 import org.apache.logging.log4j.message.Message;
 import org.apache.logging.log4j.plugins.Node;
 import org.apache.logging.log4j.plugins.Plugin;
 import org.apache.logging.log4j.plugins.PluginBuilderAttribute;
 import org.apache.logging.log4j.plugins.PluginElement;
 import org.apache.logging.log4j.plugins.PluginFactory;
 import org.apache.logging.log4j.status.StatusLogger;
 import org.apache.logging.log4j.util.StringBuilderFormattable;
 import org.apache.logging.log4j.util.Strings;
 import org.apache.logging.log4j.util.TriConsumer;

 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 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.zip.DeflaterOutputStream;
 import java.util.zip.GZIPOutputStream;

 /**
  * Lays out events in the Graylog Extended Log Format (GELF) 1.1.
  * <p>
  * This layout compresses JSON to GZIP or ZLIB (the {@code compressionType}) if
  * log event data is larger than 1024 bytes (the {@code compressionThreshold}).
  * This layout does not implement chunking.
  * </p>
  *
  * @see <a href="http://docs.graylog.org/en/latest/pages/gelf.html#gelf">GELF specification</a>
  */
 @Plugin(name = "GelfLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
 public final class GelfLayout extends AbstractStringLayout {

     public enum CompressionType {

         GZIP {
             @Override
             public DeflaterOutputStream createDeflaterOutputStream(final OutputStream os) throws IOException {
                 return new GZIPOutputStream(os);
             }
         },
         ZLIB {
             @Override
             public DeflaterOutputStream createDeflaterOutputStream(final OutputStream os) throws IOException {
                 return new DeflaterOutputStream(os);
             }
         },
         OFF {
             @Override
             public DeflaterOutputStream createDeflaterOutputStream(final OutputStream os) throws IOException {
                 return null;
             }
         };

         public abstract DeflaterOutputStream createDeflaterOutputStream(OutputStream os) throws IOException;
     }

     private static final char C = ',';
     private static final int COMPRESSION_THRESHOLD = 1024;
     private static final char Q = '\"';
     private static final String QC = "\",";
     private static final String QU = "\"_";

     private final KeyValuePair[] additionalFields;
     private final int compressionThreshold;
     private final CompressionType compressionType;
     private final String host;
     private final boolean includeStacktrace;
     private final boolean includeThreadContext;
     private final boolean includeNullDelimiter;
     private final PatternLayout layout;
     private final FieldWriter fieldWriter;

     public static class Builder<B extends Builder<B>> extends AbstractStringLayout.Builder<B>
         implements org.apache.logging.log4j.plugins.util.Builder<GelfLayout> {

         @PluginBuilderAttribute
         private String host;

         @PluginElement("AdditionalField")
         private KeyValuePair[] additionalFields;

         @PluginBuilderAttribute
         private CompressionType compressionType = CompressionType.GZIP;

         @PluginBuilderAttribute
         private int compressionThreshold = COMPRESSION_THRESHOLD;

         @PluginBuilderAttribute
         private boolean includeStacktrace = true;

         @PluginBuilderAttribute
         private boolean includeThreadContext = true;

         @PluginBuilderAttribute
         private boolean includeNullDelimiter = false;

         @PluginBuilderAttribute
         private String threadContextIncludes = null;

         @PluginBuilderAttribute
         private String threadContextExcludes = null;

         @PluginBuilderAttribute
         private String messagePattern = null;

         public Builder() {
             super();
             setCharset(StandardCharsets.UTF_8);
         }

         @Override
         public GelfLayout build() {
             ListChecker checker = null;
             if (threadContextExcludes != null) {
                 final String[] array = threadContextExcludes.split(Patterns.COMMA_SEPARATOR);
                 if (array.length > 0) {
                     List<String> excludes = new ArrayList<>(array.length);
                     for (final String str : array) {
                         excludes.add(str.trim());
                     }
                     checker = new ExcludeChecker(excludes);
                 }
             }
             if (threadContextIncludes != null) {
                 final String[] array = threadContextIncludes.split(Patterns.COMMA_SEPARATOR);
                 if (array.length > 0) {
                     List<String> includes = new ArrayList<>(array.length);
                     for (final String str : array) {
                         includes.add(str.trim());
                     }
                     checker = new IncludeChecker(includes);
                 }
             }
             if (checker == null) {
                 checker = ListChecker.NOOP_CHECKER;
             }
             PatternLayout patternLayout = null;
             if (messagePattern != null) {
                 patternLayout = PatternLayout.newBuilder().setPattern(messagePattern)
                         .setAlwaysWriteExceptions(includeStacktrace)
                         .setConfiguration(getConfiguration())
                         .build();
             }
             return new GelfLayout(getConfiguration(), host, additionalFields, compressionType, compressionThreshold,
                 includeStacktrace, includeThreadContext, includeNullDelimiter, checker, patternLayout);
         }

         public String getHost() {
             return host;
         }

         public CompressionType getCompressionType() {
             return compressionType;
         }

         public int getCompressionThreshold() {
             return compressionThreshold;
         }

         public boolean isIncludeStacktrace() {
             return includeStacktrace;
         }

         public boolean isIncludeThreadContext() {
             return includeThreadContext;
         }

         public boolean isIncludeNullDelimiter() { return includeNullDelimiter; }

         public KeyValuePair[] getAdditionalFields() {
             return additionalFields;
         }

         /**
          * The value of the <code>host</code> property (optional, defaults to local host name).
          *
          * @return this builder
          */
         public B setHost(final String host) {
             this.host = host;
             return asBuilder();
         }

         /**
          * Compression to use (optional, defaults to GZIP).
          *
          * @return this builder
          */
         public B setCompressionType(final CompressionType compressionType) {
             this.compressionType = compressionType;
             return asBuilder();
         }

         /**
          * Compress if data is larger than this number of bytes (optional, defaults to 1024).
          *
          * @return this builder
          */
         public B setCompressionThreshold(final int compressionThreshold) {
             this.compressionThreshold = compressionThreshold;
             return asBuilder();
         }

         /**
          * Whether to include full stacktrace of logged Throwables (optional, default to true).
          * If set to false, only the class name and message of the Throwable will be included.
          *
          * @return this builder
          */
         public B setIncludeStacktrace(final boolean includeStacktrace) {
             this.includeStacktrace = includeStacktrace;
             return asBuilder();
         }

         /**
          * Whether to include thread context as additional fields (optional, default to true).
          *
          * @return this builder
          */
         public B setIncludeThreadContext(final boolean includeThreadContext) {
             this.includeThreadContext = includeThreadContext;
             return asBuilder();
         }

         /**
          * Whether to include NULL byte as delimiter after each event (optional, default to false).
          * Useful for Graylog GELF TCP input.
          *
          * @return this builder
          */
         public B setIncludeNullDelimiter(final boolean includeNullDelimiter) {
             this.includeNullDelimiter = includeNullDelimiter;
             return asBuilder();
         }

         /**
          * Additional fields to set on each log event.
          *
          * @return this builder
          */
         public B setAdditionalFields(final KeyValuePair[] additionalFields) {
             this.additionalFields = additionalFields;
             return asBuilder();
         }

         /**
          * The pattern to use to format the message.
          * @param pattern the pattern string.
          * @return this builder
          */
         public B setMessagePattern(final String pattern) {
             this.messagePattern = pattern;
             return asBuilder();
         }

         /**
          * A comma separated list of thread context keys to include;
          * @param mdcIncludes the list of keys.
          * @return this builder
          */
         public B setMdcIncludes(final String mdcIncludes) {
             this.threadContextIncludes = mdcIncludes;
             return asBuilder();
         }

         /**
          * A comma separated list of thread context keys to include;
          * @param mdcExcludes the list of keys.
          * @return this builder
          */
         public B setMdcExcludes(final String mdcExcludes) {
             this.threadContextExcludes = mdcExcludes;
             return asBuilder();
         }
     }

     private GelfLayout(final Configuration config, final String host, final KeyValuePair[] additionalFields,
             final CompressionType compressionType, final int compressionThreshold, final boolean includeStacktrace,
             final boolean includeThreadContext, final boolean includeNullDelimiter, final ListChecker listChecker,
             final PatternLayout patternLayout) {
         super(config, StandardCharsets.UTF_8, null, null);
         this.host = host != null ? host : NetUtils.getLocalHostname();
         this.additionalFields = additionalFields != null ? additionalFields : new KeyValuePair[0];
         if (config == null) {
             for (final KeyValuePair additionalField : this.additionalFields) {
                 if (valueNeedsLookup(additionalField.getValue())) {
                     throw new IllegalArgumentException("configuration needs to be set when there are additional fields with variables");
                 }
             }
         }
         this.compressionType = compressionType;
         this.compressionThreshold = compressionThreshold;
         this.includeStacktrace = includeStacktrace;
         this.includeThreadContext = includeThreadContext;
         this.includeNullDelimiter = includeNullDelimiter;
         if (includeNullDelimiter && compressionType != CompressionType.OFF) {
             throw new IllegalArgumentException("null delimiter cannot be used with compression");
         }
         this.fieldWriter = new FieldWriter(listChecker);
         this.layout = patternLayout;
     }

     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();
         sb.append("host=").append(host);
         sb.append(", compressionType=").append(compressionType.toString());
         sb.append(", compressionThreshold=").append(compressionThreshold);
         sb.append(", includeStackTrace=").append(includeStacktrace);
         sb.append(", includeThreadContext=").append(includeThreadContext);
         sb.append(", includeNullDelimiter=").append(includeNullDelimiter);
         String threadVars = fieldWriter.getChecker().toString();
         if (threadVars.length() > 0) {
             sb.append(", ").append(threadVars);
         }
         if (layout != null) {
             sb.append(", PatternLayout{").append(layout.toString()).append("}");
         }
         return sb.toString();
     }

     @PluginFactory
     public static <B extends Builder<B>> B newBuilder() {
         return new Builder<B>().asBuilder();
     }

     @Override
     public Map<String, String> getContentFormat() {
         return Collections.emptyMap();
     }

     @Override
     public String getContentType() {
         return "application/json; charset=" + this.getCharset();
     }

     @Override
     public byte[] toByteArray(final LogEvent event) {
         final StringBuilder text = toText(event, getStringBuilder(), false);
         final byte[] bytes = getBytes(text.toString());
         return compressionType != CompressionType.OFF && bytes.length > compressionThreshold ? compress(bytes) : bytes;
     }

     @Override
     public void encode(final LogEvent event, final ByteBufferDestination destination) {
         if (compressionType != CompressionType.OFF) {
             super.encode(event, destination);
             return;
         }
         final StringBuilder text = toText(event, getStringBuilder(), true);
         final Encoder<StringBuilder> helper = getStringBuilderEncoder();
         helper.encode(text, destination);
     }

     private byte[] compress(final byte[] bytes) {
         try {
             final ByteArrayOutputStream baos = new ByteArrayOutputStream(compressionThreshold / 8);
             try (final DeflaterOutputStream stream = compressionType.createDeflaterOutputStream(baos)) {
                 if (stream == null) {
                     return bytes;
                 }
                 stream.write(bytes);
                 stream.finish();
             }
             return baos.toByteArray();
         } catch (final IOException e) {
             StatusLogger.getLogger().error(e);
             return bytes;
         }
     }

     @Override
     public String toSerializable(final LogEvent event) {
         final StringBuilder text = toText(event, getStringBuilder(), false);
         return text.toString();
     }

     private StringBuilder toText(final LogEvent event, final StringBuilder builder, final boolean gcFree) {
         builder.append('{');
         builder.append("\"version\":\"1.1\",");
         builder.append("\"host\":\"");
         JsonUtils.quoteAsString(toNullSafeString(host), builder);
         builder.append(QC);
         builder.append("\"timestamp\":").append(formatTimestamp(event.getTimeMillis())).append(C);
         builder.append("\"level\":").append(formatLevel(event.getLevel())).append(C);
         if (event.getThreadName() != null) {
             builder.append("\"_thread\":\"");
             JsonUtils.quoteAsString(event.getThreadName(), builder);
             builder.append(QC);
         }
         if (event.getLoggerName() != null) {
             builder.append("\"_logger\":\"");
             JsonUtils.quoteAsString(event.getLoggerName(), builder);
             builder.append(QC);
         }
         if (additionalFields.length > 0) {
             final StrSubstitutor strSubstitutor = getConfiguration().getStrSubstitutor();
             for (final KeyValuePair additionalField : additionalFields) {
                 builder.append(QU);
                 JsonUtils.quoteAsString(additionalField.getKey(), builder);
                 builder.append("\":\"");
                 final String value = valueNeedsLookup(additionalField.getValue())
                     ? strSubstitutor.replace(event, additionalField.getValue())
                     : additionalField.getValue();
                 JsonUtils.quoteAsString(toNullSafeString(value), builder);
                 builder.append(QC);
             }
         }
         if (includeThreadContext) {
             event.getContextData().forEach(fieldWriter, builder);
         }

         if (event.getThrown() != null || layout != null) {
             builder.append("\"full_message\":\"");
             if (layout != null) {
                 final StringBuilder messageBuffer = getMessageStringBuilder();
                 layout.serialize(event, messageBuffer);
                 JsonUtils.quoteAsString(messageBuffer, builder);
             } else {
                 if (includeStacktrace) {
                     JsonUtils.quoteAsString(formatThrowable(event.getThrown()), builder);
                 } else {
                     JsonUtils.quoteAsString(event.getThrown().toString(), builder);
                 }
             }
             builder.append(QC);
         }

         builder.append("\"short_message\":\"");
         final Message message = event.getMessage();
         if (message instanceof CharSequence) {
             JsonUtils.quoteAsString(((CharSequence) message), builder);
         } else if (gcFree && message instanceof StringBuilderFormattable) {
             final StringBuilder messageBuffer = getMessageStringBuilder();
             try {
                 ((StringBuilderFormattable) message).formatTo(messageBuffer);
                 JsonUtils.quoteAsString(messageBuffer, builder);
             } finally {
                 trimToMaxSize(messageBuffer);
             }
         } else {
             JsonUtils.quoteAsString(toNullSafeString(message.getFormattedMessage()), builder);
         }
         builder.append(Q);
         builder.append('}');
         if (includeNullDelimiter) {
             builder.append('\0');
         }
         return builder;
     }

     private static boolean valueNeedsLookup(final String value) {
         return value != null && value.contains("${");
     }

     private static class FieldWriter implements TriConsumer<String, Object, StringBuilder> {
         private final ListChecker checker;

         FieldWriter(ListChecker checker) {
             this.checker = checker;
         }

         @Override
         public void accept(final String key, final Object value, final StringBuilder stringBuilder) {
             if (checker.check(key)) {
                 stringBuilder.append(QU);
                 JsonUtils.quoteAsString(key, stringBuilder);
                 stringBuilder.append("\":\"");
                 JsonUtils.quoteAsString(toNullSafeString(String.valueOf(value)), stringBuilder);
                 stringBuilder.append(QC);
             }
         }

         public ListChecker getChecker() {
             return checker;
         }
     };

     private static final ThreadLocal<StringBuilder> messageStringBuilder = new ThreadLocal<>();

     private static StringBuilder getMessageStringBuilder() {
         StringBuilder result = messageStringBuilder.get();
         if (result == null) {
             result = new StringBuilder(DEFAULT_STRING_BUILDER_SIZE);
             messageStringBuilder.set(result);
         }
         result.setLength(0);
         return result;
     }

     private static CharSequence toNullSafeString(final CharSequence s) {
         return s == null ? Strings.EMPTY : s;
     }

     /**
      * Non-private to make it accessible from unit test.
      */
     static CharSequence formatTimestamp(final long timeMillis) {
         if (timeMillis < 1000) {
             return "0";
         }
         final StringBuilder builder = getTimestampStringBuilder();
         builder.append(timeMillis);
         builder.insert(builder.length() - 3, '.');
         return builder;
     }

     private static final ThreadLocal<StringBuilder> timestampStringBuilder = new ThreadLocal<>();

     private static StringBuilder getTimestampStringBuilder() {
         StringBuilder result = timestampStringBuilder.get();
         if (result == null) {
             result = new StringBuilder(20);
             timestampStringBuilder.set(result);
         }
         result.setLength(0);
         return result;
     }

     /**
      * http://en.wikipedia.org/wiki/Syslog#Severity_levels
      */
     private int formatLevel(final Level level) {
         return Severity.getSeverity(level).getCode();
     }

     /**
      * Non-private to make it accessible from unit test.
      */
     static CharSequence formatThrowable(final Throwable throwable) {
         // stack traces are big enough to provide a reasonably large initial capacity here
         final StringWriter sw = new StringWriter(2048);
         final PrintWriter pw = new PrintWriter(sw);
         throwable.printStackTrace(pw);
         pw.flush();
         return sw.getBuffer();
     }
 }
	/*
	* 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 org.apache.logging.log4j.Level;
	import org.apache.logging.log4j.core.Layout;
	import org.apache.logging.log4j.core.LogEvent;
	import org.apache.logging.log4j.core.config.Configuration;
	import org.apache.logging.log4j.core.layout.internal.ExcludeChecker;
	import org.apache.logging.log4j.core.layout.internal.IncludeChecker;
	import org.apache.logging.log4j.core.layout.internal.ListChecker;
	import org.apache.logging.log4j.core.lookup.StrSubstitutor;
	import org.apache.logging.log4j.core.net.Severity;
	import org.apache.logging.log4j.core.util.JsonUtils;
	import org.apache.logging.log4j.core.util.KeyValuePair;
	import org.apache.logging.log4j.core.util.NetUtils;
	import org.apache.logging.log4j.core.util.Patterns;
	import org.apache.logging.log4j.message.Message;
	import org.apache.logging.log4j.plugins.Node;
	import org.apache.logging.log4j.plugins.Plugin;
	import org.apache.logging.log4j.plugins.PluginBuilderAttribute;
	import org.apache.logging.log4j.plugins.PluginElement;
	import org.apache.logging.log4j.plugins.PluginFactory;
	import org.apache.logging.log4j.status.StatusLogger;
	import org.apache.logging.log4j.util.StringBuilderFormattable;
	import org.apache.logging.log4j.util.Strings;
	import org.apache.logging.log4j.util.TriConsumer;

	import java.io.ByteArrayOutputStream;
	import java.io.IOException;
	import java.io.OutputStream;
	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.zip.DeflaterOutputStream;
	import java.util.zip.GZIPOutputStream;

	/**
	* Lays out events in the Graylog Extended Log Format (GELF) 1.1.
	* <p>
	* This layout compresses JSON to GZIP or ZLIB (the {@code compressionType}) if
	* log event data is larger than 1024 bytes (the {@code compressionThreshold}).
	* This layout does not implement chunking.
	* </p>
	*
	* @see <a href="http://docs.graylog.org/en/latest/pages/gelf.html#gelf">GELF specification</a>
	*/
	@Plugin(name = "GelfLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
	public final class GelfLayout extends AbstractStringLayout {

	public enum CompressionType {

	GZIP {
	@Override
	public DeflaterOutputStream createDeflaterOutputStream(final OutputStream os) throws IOException {
	return new GZIPOutputStream(os);
	}
	},
	ZLIB {
	@Override
	public DeflaterOutputStream createDeflaterOutputStream(final OutputStream os) throws IOException {
	return new DeflaterOutputStream(os);
	}
	},
	OFF {
	@Override
	public DeflaterOutputStream createDeflaterOutputStream(final OutputStream os) throws IOException {
	return null;
	}
	};

	public abstract DeflaterOutputStream createDeflaterOutputStream(OutputStream os) throws IOException;
	}

	private static final char C = ',';
	private static final int COMPRESSION_THRESHOLD = 1024;
	private static final char Q = '\"';
	private static final String QC = "\",";
	private static final String QU = "\"_";

	private final KeyValuePair[] additionalFields;
	private final int compressionThreshold;
	private final CompressionType compressionType;
	private final String host;
	private final boolean includeStacktrace;
	private final boolean includeThreadContext;
	private final boolean includeNullDelimiter;
	private final PatternLayout layout;
	private final FieldWriter fieldWriter;

	public static class Builder<B extends Builder<B>> extends AbstractStringLayout.Builder<B>
	implements org.apache.logging.log4j.plugins.util.Builder<GelfLayout> {

	@PluginBuilderAttribute
	private String host;

	@PluginElement("AdditionalField")
	private KeyValuePair[] additionalFields;

	@PluginBuilderAttribute
	private CompressionType compressionType = CompressionType.GZIP;

	@PluginBuilderAttribute
	private int compressionThreshold = COMPRESSION_THRESHOLD;

	@PluginBuilderAttribute
	private boolean includeStacktrace = true;

	@PluginBuilderAttribute
	private boolean includeThreadContext = true;

	@PluginBuilderAttribute
	private boolean includeNullDelimiter = false;

	@PluginBuilderAttribute
	private String threadContextIncludes = null;

	@PluginBuilderAttribute
	private String threadContextExcludes = null;

	@PluginBuilderAttribute
	private String messagePattern = null;

	public Builder() {
	super();
	setCharset(StandardCharsets.UTF_8);
	}

	@Override
	public GelfLayout build() {
	ListChecker checker = null;
	if (threadContextExcludes != null) {
	final String[] array = threadContextExcludes.split(Patterns.COMMA_SEPARATOR);
	if (array.length > 0) {
	List<String> excludes = new ArrayList<>(array.length);
	for (final String str : array) {
	excludes.add(str.trim());
	}
	checker = new ExcludeChecker(excludes);
	}
	}
	if (threadContextIncludes != null) {
	final String[] array = threadContextIncludes.split(Patterns.COMMA_SEPARATOR);
	if (array.length > 0) {
	List<String> includes = new ArrayList<>(array.length);
	for (final String str : array) {
	includes.add(str.trim());
	}
	checker = new IncludeChecker(includes);
	}
	}
	if (checker == null) {
	checker = ListChecker.NOOP_CHECKER;
	}
	PatternLayout patternLayout = null;
	if (messagePattern != null) {
	patternLayout = PatternLayout.newBuilder().setPattern(messagePattern)
	.setAlwaysWriteExceptions(includeStacktrace)
	.setConfiguration(getConfiguration())
	.build();
	}
	return new GelfLayout(getConfiguration(), host, additionalFields, compressionType, compressionThreshold,
	includeStacktrace, includeThreadContext, includeNullDelimiter, checker, patternLayout);
	}

	public String getHost() {
	return host;
	}

	public CompressionType getCompressionType() {
	return compressionType;
	}

	public int getCompressionThreshold() {
	return compressionThreshold;
	}

	public boolean isIncludeStacktrace() {
	return includeStacktrace;
	}

	public boolean isIncludeThreadContext() {
	return includeThreadContext;
	}

	public boolean isIncludeNullDelimiter() { return includeNullDelimiter; }

	public KeyValuePair[] getAdditionalFields() {
	return additionalFields;
	}

	/**
	* The value of the <code>host</code> property (optional, defaults to local host name).
	*
	* @return this builder
	*/
	public B setHost(final String host) {
	this.host = host;
	return asBuilder();
	}

	/**
	* Compression to use (optional, defaults to GZIP).
	*
	* @return this builder
	*/
	public B setCompressionType(final CompressionType compressionType) {
	this.compressionType = compressionType;
	return asBuilder();
	}

	/**
	* Compress if data is larger than this number of bytes (optional, defaults to 1024).
	*
	* @return this builder
	*/
	public B setCompressionThreshold(final int compressionThreshold) {
	this.compressionThreshold = compressionThreshold;
	return asBuilder();
	}

	/**
	* Whether to include full stacktrace of logged Throwables (optional, default to true).
	* If set to false, only the class name and message of the Throwable will be included.
	*
	* @return this builder
	*/
	public B setIncludeStacktrace(final boolean includeStacktrace) {
	this.includeStacktrace = includeStacktrace;
	return asBuilder();
	}

	/**
	* Whether to include thread context as additional fields (optional, default to true).
	*
	* @return this builder
	*/
	public B setIncludeThreadContext(final boolean includeThreadContext) {
	this.includeThreadContext = includeThreadContext;
	return asBuilder();
	}

	/**
	* Whether to include NULL byte as delimiter after each event (optional, default to false).
	* Useful for Graylog GELF TCP input.
	*
	* @return this builder
	*/
	public B setIncludeNullDelimiter(final boolean includeNullDelimiter) {
	this.includeNullDelimiter = includeNullDelimiter;
	return asBuilder();
	}

	/**
	* Additional fields to set on each log event.
	*
	* @return this builder
	*/
	public B setAdditionalFields(final KeyValuePair[] additionalFields) {
	this.additionalFields = additionalFields;
	return asBuilder();
	}

	/**
	* The pattern to use to format the message.
	* @param pattern the pattern string.
	* @return this builder
	*/
	public B setMessagePattern(final String pattern) {
	this.messagePattern = pattern;
	return asBuilder();
	}

	/**
	* A comma separated list of thread context keys to include;
	* @param mdcIncludes the list of keys.
	* @return this builder
	*/
	public B setMdcIncludes(final String mdcIncludes) {
	this.threadContextIncludes = mdcIncludes;
	return asBuilder();
	}

	/**
	* A comma separated list of thread context keys to include;
	* @param mdcExcludes the list of keys.
	* @return this builder
	*/
	public B setMdcExcludes(final String mdcExcludes) {
	this.threadContextExcludes = mdcExcludes;
	return asBuilder();
	}
	}

	private GelfLayout(final Configuration config, final String host, final KeyValuePair[] additionalFields,
	final CompressionType compressionType, final int compressionThreshold, final boolean includeStacktrace,
	final boolean includeThreadContext, final boolean includeNullDelimiter, final ListChecker listChecker,
	final PatternLayout patternLayout) {
	super(config, StandardCharsets.UTF_8, null, null);
	this.host = host != null ? host : NetUtils.getLocalHostname();
	this.additionalFields = additionalFields != null ? additionalFields : new KeyValuePair[0];
	if (config == null) {
	for (final KeyValuePair additionalField : this.additionalFields) {
	if (valueNeedsLookup(additionalField.getValue())) {
	throw new IllegalArgumentException("configuration needs to be set when there are additional fields with variables");
	}
	}
	}
	this.compressionType = compressionType;
	this.compressionThreshold = compressionThreshold;
	this.includeStacktrace = includeStacktrace;
	this.includeThreadContext = includeThreadContext;
	this.includeNullDelimiter = includeNullDelimiter;
	if (includeNullDelimiter && compressionType != CompressionType.OFF) {
	throw new IllegalArgumentException("null delimiter cannot be used with compression");
	}
	this.fieldWriter = new FieldWriter(listChecker);
	this.layout = patternLayout;
	}

	@Override
	public String toString() {
	StringBuilder sb = new StringBuilder();
	sb.append("host=").append(host);
	sb.append(", compressionType=").append(compressionType.toString());
	sb.append(", compressionThreshold=").append(compressionThreshold);
	sb.append(", includeStackTrace=").append(includeStacktrace);
	sb.append(", includeThreadContext=").append(includeThreadContext);
	sb.append(", includeNullDelimiter=").append(includeNullDelimiter);
	String threadVars = fieldWriter.getChecker().toString();
	if (threadVars.length() > 0) {
	sb.append(", ").append(threadVars);
	}
	if (layout != null) {
	sb.append(", PatternLayout{").append(layout.toString()).append("}");
	}
	return sb.toString();
	}

	@PluginFactory
	public static <B extends Builder<B>> B newBuilder() {
	return new Builder<B>().asBuilder();
	}

	@Override
	public Map<String, String> getContentFormat() {
	return Collections.emptyMap();
	}

	@Override
	public String getContentType() {
	return "application/json; charset=" + this.getCharset();
	}

	@Override
	public byte[] toByteArray(final LogEvent event) {
	final StringBuilder text = toText(event, getStringBuilder(), false);
	final byte[] bytes = getBytes(text.toString());
	return compressionType != CompressionType.OFF && bytes.length > compressionThreshold ? compress(bytes) : bytes;
	}

	@Override
	public void encode(final LogEvent event, final ByteBufferDestination destination) {
	if (compressionType != CompressionType.OFF) {
	super.encode(event, destination);
	return;
	}
	final StringBuilder text = toText(event, getStringBuilder(), true);
	final Encoder<StringBuilder> helper = getStringBuilderEncoder();
	helper.encode(text, destination);
	}

	private byte[] compress(final byte[] bytes) {
	try {
	final ByteArrayOutputStream baos = new ByteArrayOutputStream(compressionThreshold / 8);
	try (final DeflaterOutputStream stream = compressionType.createDeflaterOutputStream(baos)) {
	if (stream == null) {
	return bytes;
	}
	stream.write(bytes);
	stream.finish();
	}
	return baos.toByteArray();
	} catch (final IOException e) {
	StatusLogger.getLogger().error(e);
	return bytes;
	}
	}

	@Override
	public String toSerializable(final LogEvent event) {
	final StringBuilder text = toText(event, getStringBuilder(), false);
	return text.toString();
	}

	private StringBuilder toText(final LogEvent event, final StringBuilder builder, final boolean gcFree) {
	builder.append('{');
	builder.append("\"version\":\"1.1\",");
	builder.append("\"host\":\"");
	JsonUtils.quoteAsString(toNullSafeString(host), builder);
	builder.append(QC);
	builder.append("\"timestamp\":").append(formatTimestamp(event.getTimeMillis())).append(C);
	builder.append("\"level\":").append(formatLevel(event.getLevel())).append(C);
	if (event.getThreadName() != null) {
	builder.append("\"_thread\":\"");
	JsonUtils.quoteAsString(event.getThreadName(), builder);
	builder.append(QC);
	}
	if (event.getLoggerName() != null) {
	builder.append("\"_logger\":\"");
	JsonUtils.quoteAsString(event.getLoggerName(), builder);
	builder.append(QC);
	}
	if (additionalFields.length > 0) {
	final StrSubstitutor strSubstitutor = getConfiguration().getStrSubstitutor();
	for (final KeyValuePair additionalField : additionalFields) {
	builder.append(QU);
	JsonUtils.quoteAsString(additionalField.getKey(), builder);
	builder.append("\":\"");
	final String value = valueNeedsLookup(additionalField.getValue())
	? strSubstitutor.replace(event, additionalField.getValue())
	: additionalField.getValue();
	JsonUtils.quoteAsString(toNullSafeString(value), builder);
	builder.append(QC);
	}
	}
	if (includeThreadContext) {
	event.getContextData().forEach(fieldWriter, builder);
	}

	if (event.getThrown() != null \|\| layout != null) {
	builder.append("\"full_message\":\"");
	if (layout != null) {
	final StringBuilder messageBuffer = getMessageStringBuilder();
	layout.serialize(event, messageBuffer);
	JsonUtils.quoteAsString(messageBuffer, builder);
	} else {
	if (includeStacktrace) {
	JsonUtils.quoteAsString(formatThrowable(event.getThrown()), builder);
	} else {
	JsonUtils.quoteAsString(event.getThrown().toString(), builder);
	}
	}
	builder.append(QC);
	}

	builder.append("\"short_message\":\"");
	final Message message = event.getMessage();
	if (message instanceof CharSequence) {
	JsonUtils.quoteAsString(((CharSequence) message), builder);
	} else if (gcFree && message instanceof StringBuilderFormattable) {
	final StringBuilder messageBuffer = getMessageStringBuilder();
	try {
	((StringBuilderFormattable) message).formatTo(messageBuffer);
	JsonUtils.quoteAsString(messageBuffer, builder);
	} finally {
	trimToMaxSize(messageBuffer);
	}
	} else {
	JsonUtils.quoteAsString(toNullSafeString(message.getFormattedMessage()), builder);
	}
	builder.append(Q);
	builder.append('}');
	if (includeNullDelimiter) {
	builder.append('\0');
	}
	return builder;
	}

	private static boolean valueNeedsLookup(final String value) {
	return value != null && value.contains("${");
	}

	private static class FieldWriter implements TriConsumer<String, Object, StringBuilder> {
	private final ListChecker checker;

	FieldWriter(ListChecker checker) {
	this.checker = checker;
	}

	@Override
	public void accept(final String key, final Object value, final StringBuilder stringBuilder) {
	if (checker.check(key)) {
	stringBuilder.append(QU);
	JsonUtils.quoteAsString(key, stringBuilder);
	stringBuilder.append("\":\"");
	JsonUtils.quoteAsString(toNullSafeString(String.valueOf(value)), stringBuilder);
	stringBuilder.append(QC);
	}
	}

	public ListChecker getChecker() {
	return checker;
	}
	};

	private static final ThreadLocal<StringBuilder> messageStringBuilder = new ThreadLocal<>();

	private static StringBuilder getMessageStringBuilder() {
	StringBuilder result = messageStringBuilder.get();
	if (result == null) {
	result = new StringBuilder(DEFAULT_STRING_BUILDER_SIZE);
	messageStringBuilder.set(result);
	}
	result.setLength(0);
	return result;
	}

	private static CharSequence toNullSafeString(final CharSequence s) {
	return s == null ? Strings.EMPTY : s;
	}

	/**
	* Non-private to make it accessible from unit test.
	*/
	static CharSequence formatTimestamp(final long timeMillis) {
	if (timeMillis < 1000) {
	return "0";
	}
	final StringBuilder builder = getTimestampStringBuilder();
	builder.append(timeMillis);
	builder.insert(builder.length() - 3, '.');
	return builder;
	}

	private static final ThreadLocal<StringBuilder> timestampStringBuilder = new ThreadLocal<>();

	private static StringBuilder getTimestampStringBuilder() {
	StringBuilder result = timestampStringBuilder.get();
	if (result == null) {
	result = new StringBuilder(20);
	timestampStringBuilder.set(result);
	}
	result.setLength(0);
	return result;
	}

	/**
	* http://en.wikipedia.org/wiki/Syslog#Severity_levels
	*/
	private int formatLevel(final Level level) {
	return Severity.getSeverity(level).getCode();
	}

	/**
	* Non-private to make it accessible from unit test.
	*/
	static CharSequence formatThrowable(final Throwable throwable) {
	// stack traces are big enough to provide a reasonably large initial capacity here
	final StringWriter sw = new StringWriter(2048);
	final PrintWriter pw = new PrintWriter(sw);
	throwable.printStackTrace(pw);
	pw.flush();
	return sw.getBuffer();
	}
	}