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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements. See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache license, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License. You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the license for the specific language governing permissions and
15   * limitations under the license.
16   */
17  package org.apache.logging.log4j.core.layout;
18  
19  import org.apache.logging.log4j.core.LogEvent;
20  import org.apache.logging.log4j.core.config.plugins.Plugin;
21  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
22  
23  import java.io.ByteArrayOutputStream;
24  import java.io.IOException;
25  import java.io.ObjectOutputStream;
26  import java.io.OutputStream;
27  
28  /**
29   * Format a LogEvent in its serialized form.
30   */
31  @Plugin(name = "SerializedLayout", type = "Core", elementType = "layout", printObject = true)
32  public final class SerializedLayout extends AbstractLayout<LogEvent> {
33  
34      private static byte[] header;
35  
36      static {
37          ByteArrayOutputStream baos = new ByteArrayOutputStream();
38          try {
39              ObjectOutputStream oos = new ObjectOutputStream(baos);
40              oos.close();
41              header = baos.toByteArray();
42          } catch (Exception ex) {
43              LOGGER.error("Unable to generate Object stream header", ex);
44          }
45      }
46  
47      private SerializedLayout() {
48      }
49  
50      /**
51       * Formats a {@link org.apache.logging.log4j.core.LogEvent} in conformance with the log4j.dtd.
52       *
53       * @param event The LogEvent.
54       * @return the formatted LogEvent.
55       */
56      public byte[] toByteArray(final LogEvent event) {
57          ByteArrayOutputStream baos = new ByteArrayOutputStream();
58          try {
59              ObjectOutputStream oos = new PrivateObjectOutputStream(baos);
60              try {
61                  oos.writeObject(event);
62              } finally {
63                  oos.close();
64              }
65          } catch (IOException ioe) {
66              LOGGER.error("Serialization of LogEvent failed.", ioe);
67          }
68          return baos.toByteArray();
69      }
70  
71      /**
72       * Returns the LogEvent.
73       *
74       * @param event The Logging Event.
75       * @return The LogEvent.
76       */
77      public LogEvent toSerializable(final LogEvent event) {
78          return event;
79      }
80  
81      /**
82       * Create a SerializedLayout.
83       * @return A SerializedLayout.
84       */
85      @PluginFactory
86      public static SerializedLayout createLayout() {
87  
88          return new SerializedLayout();
89      }
90  
91      @Override
92      public byte[] getHeader() {
93          return header;
94      }
95  
96      /**
97       * The stream header will be written in the Manager so skip it here.
98       */
99      private class PrivateObjectOutputStream extends ObjectOutputStream {
100 
101         public PrivateObjectOutputStream(OutputStream os) throws IOException {
102             super(os);
103         }
104 
105         @Override
106         protected void writeStreamHeader() {
107         }
108     }
109 }