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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.status;
18  
19  import java.io.IOException;
20  import java.io.PrintStream;
21  
22  import org.apache.logging.log4j.Level;
23  
24  /**
25   * StatusListener that writes to the Console.
26   */
27  @SuppressWarnings("UseOfSystemOutOrSystemErr")
28  public class StatusConsoleListener implements StatusListener {
29  
30      private Level level = Level.FATAL;
31      private String[] filters = null;
32      private final PrintStream stream;
33  
34      /**
35       * Creates the StatusConsoleListener using the supplied Level.
36       * @param level The Level of status messages that should appear on the console.
37       */
38      public StatusConsoleListener(final Level level) {
39          this(level, System.out);
40      }
41  
42      /**
43       * Creates the StatusConsoleListener using the supplied Level. Make sure not to use a logger stream of some sort
44       * to avoid creating an infinite loop of indirection!
45       * @param level The Level of status messages that should appear on the console.
46       * @param stream The PrintStream to write to.
47       * @throws IllegalArgumentException if the PrintStream argument is {@code null}.
48       */
49      public StatusConsoleListener(final Level level, final PrintStream stream) {
50          if (stream == null) {
51              throw new IllegalArgumentException("You must provide a stream to use for this listener.");
52          }
53          this.level = level;
54          this.stream = stream;
55      }
56  
57      /**
58       * Sets the level to a new value.
59       * @param level The new Level.
60       */
61      public void setLevel(final Level level) {
62          this.level = level;
63      }
64  
65      /**
66       * Return the Log Level for which the Listener should receive events.
67       * @return the Log Level.
68       */
69      @Override
70      public Level getStatusLevel() {
71          return this.level;
72      }
73  
74      /**
75       * Writes status messages to the console.
76       * @param data The StatusData.
77       */
78      @Override
79      public void log(final StatusData data) {
80          if (!filtered(data)) {
81              stream.println(data.getFormattedStatus());
82          }
83      }
84  
85      /**
86       * Adds package name filters to exclude.
87       * @param filters An array of package names to exclude.
88       */
89      public void setFilters(final String... filters) {
90          this.filters = filters;
91      }
92  
93      private boolean filtered(final StatusData data) {
94          if (filters == null) {
95              return false;
96          }
97          final String caller = data.getStackTraceElement().getClassName();
98          for (final String filter : filters) {
99              if (caller.startsWith(filter)) {
100                 return true;
101             }
102         }
103         return false;
104     }
105 
106     @Override
107     public void close() throws IOException {
108         // only want to close non-system streams
109         if (this.stream != System.out && this.stream != System.err) {
110             this.stream.close();
111         }
112     }
113 }