View Javadoc

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.appender.rewrite;
18  
19  import org.apache.logging.log4j.Logger;
20  import org.apache.logging.log4j.core.LogEvent;
21  import org.apache.logging.log4j.core.config.Configuration;
22  import org.apache.logging.log4j.core.config.Property;
23  import org.apache.logging.log4j.core.config.plugins.Plugin;
24  import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
25  import org.apache.logging.log4j.core.config.plugins.PluginElement;
26  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
27  import org.apache.logging.log4j.core.impl.Log4jLogEvent;
28  import org.apache.logging.log4j.status.StatusLogger;
29  
30  import java.util.Arrays;
31  import java.util.HashMap;
32  import java.util.List;
33  import java.util.Map;
34  
35  /**
36   * This policy modifies events by replacing or possibly adding keys and values to the MapMessage.
37   */
38  @Plugin(name = "PropertiesRewritePolicy", type = "Core", elementType = "rewritePolicy", printObject = true)
39  public final class PropertiesRewritePolicy implements RewritePolicy {
40      /**
41       * Allow subclasses access to the status logger without creating another instance.
42       */
43      protected static final Logger LOGGER = StatusLogger.getLogger();
44  
45      private final Map<Property, Boolean> properties;
46  
47      private final Configuration config;
48  
49      private PropertiesRewritePolicy(Configuration config, List<Property> props) {
50          this.config = config;
51          this.properties = new HashMap<Property, Boolean>(props.size());
52          for (Property prop : props) {
53              boolean interpolate = prop.getValue().contains("${");
54              properties.put(prop, interpolate);
55          }
56      }
57  
58      /**
59       * Rewrite the event.
60       * @param source a logging event that may be returned or
61       * used to create a new logging event.
62       * @return The LogEvent after rewriting.
63       */
64      public LogEvent rewrite(LogEvent source) {
65          Map<String, String> props = new HashMap<String, String>(source.getContextMap());
66          for (Map.Entry<Property, Boolean> entry : properties.entrySet()) {
67              Property prop = entry.getKey();
68              if (!props.containsKey(prop.getName())) {
69                  props.put(prop.getName(), entry.getValue() ?
70                      config.getSubst().replace(prop.getValue()) : prop.getValue());
71              }
72          }
73  
74          return new Log4jLogEvent(source.getLoggerName(), source.getMarker(), source.getFQCN(), source.getLevel(),
75              source.getMessage(), source.getThrown(), props, source.getContextStack(), source.getThreadName(),
76              source.getSource(), source.getMillis());
77      }
78  
79      @Override
80      public String toString() {
81          StringBuilder sb = new StringBuilder();
82          sb.append(" {");
83          boolean first = true;
84          for (Map.Entry<Property, Boolean> entry : properties.entrySet()) {
85              if (!first) {
86                  sb.append(", ");
87              }
88              Property prop = entry.getKey();
89              sb.append(prop.getName()).append("=").append(prop.getValue());
90              first = false;
91          }
92          sb.append("}");
93          return sb.toString();
94      }
95  
96      /**
97       * The factory method to create the PropertiesRewritePolicy.
98       * @param config The Configuration.
99       * @param props key/value pairs for the new keys and values.
100      * @return The PropertiesRewritePolicy.
101      */
102     @PluginFactory
103     public static PropertiesRewritePolicy createPolicy(@PluginConfiguration Configuration config,
104                                                 @PluginElement("properties") Property[] props) {
105         if (props == null || props.length == 0) {
106             LOGGER.error("Properties must be specified for the PropertiesRewritePolicy");
107             return null;
108         }
109         List<Property> properties = Arrays.asList(props);
110         return new PropertiesRewritePolicy(config, properties);
111     }
112 }