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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  
18  package org.apache.log4j.chainsaw.layout;
19  
20  import java.io.BufferedReader;
21  import java.io.InputStreamReader;
22  import java.net.URL;
23  
24  import org.apache.log4j.LogManager;
25  import org.apache.log4j.PatternLayout;
26  
27  
28  /**
29   * Factory class to load and cache Layout information from resources.
30   * 
31   * @author Paul Smith <psmith@apache.org>
32   */
33  public class DefaultLayoutFactory {
34    private volatile static String defaultPatternLayout = null;
35  
36    private DefaultLayoutFactory() {
37    }
38  
39    public static String getDefaultPatternLayout() {
40        return getPatternLayout("org/apache/log4j/chainsaw/layout/DefaultDetailLayout.html");
41    }
42    public static String getFullPatternLayout() {
43        return getPatternLayout("org/apache/log4j/chainsaw/layout/FullDetailLayout.html");
44    }
45  
46    private static String getPatternLayout(String fileNamePath) {
47        StringBuffer content = new StringBuffer();
48        URL defaultLayoutURL =
49          DefaultLayoutFactory.class.getClassLoader().getResource(fileNamePath);
50  
51        if (defaultLayoutURL == null) {
52          LogManager.getLogger(DefaultLayoutFactory.class).warn(
53            "Could not locate the default Layout for Event Details and Tooltips");
54        } else {
55          try {
56            BufferedReader reader = null;
57  
58            try {
59              reader =
60                new BufferedReader(
61                  new InputStreamReader(defaultLayoutURL.openStream()));
62  
63              String line = "";
64  
65              while ((line = reader.readLine()) != null) {
66                content.append(line).append("\n");
67              }
68            } finally {
69              if (reader != null) {
70                reader.close();
71              }
72            }
73          } catch (Exception e) {
74            content = new StringBuffer(PatternLayout.TTCC_CONVERSION_PATTERN);
75          }
76          String trimmedContent = content.toString().trim();
77          //the default docs contain the apache license header, strip that out before displaying
78          String startComment = "<!--";
79          String endComment = "-->";
80          if (trimmedContent.startsWith(startComment)) {
81              int endIndex = trimmedContent.indexOf(endComment);
82              if (endIndex > -1) {
83                  trimmedContent = trimmedContent.substring(endIndex + endComment.length()).trim();
84              }
85          }
86          defaultPatternLayout = trimmedContent;
87        }
88  
89      return defaultPatternLayout;
90    }
91  }