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.taglib;
18  
19  import java.util.HashSet;
20  import java.util.Set;
21  
22  import javax.servlet.jsp.JspException;
23  import javax.servlet.jsp.PageContext;
24  
25  import org.apache.logging.log4j.Level;
26  import org.apache.logging.log4j.Logger;
27  import org.apache.logging.log4j.LoggingException;
28  import org.apache.logging.log4j.Marker;
29  import org.apache.logging.log4j.message.MessageFactory;
30  import org.apache.logging.log4j.spi.AbstractLogger;
31  import org.apache.logging.log4j.status.StatusLogger;
32  
33  /**
34   * Provides support for logging tags.
35   *
36   * @since 2.0
37   */
38  final class TagUtils {
39      private static final StatusLogger LOGGER = StatusLogger.getLogger();
40  
41      private static final Set<Object> WARNED_FOR = new HashSet<Object>();
42  
43      private static final String LOGGER_SCOPE_ATTRIBUTE = "org.apache.logging.log4j.taglib.LOGGER_SCOPE_ATTRIBUTE";
44  
45      private TagUtils() {
46          throw new RuntimeException("TagUtils cannot be instantiated.");
47      }
48  
49      static int getScope(final String scope) {
50          if ("request".equalsIgnoreCase(scope)) {
51              return PageContext.REQUEST_SCOPE;
52          }
53          if ("session".equalsIgnoreCase(scope)) {
54              return PageContext.SESSION_SCOPE;
55          }
56          if ("application".equalsIgnoreCase(scope)) {
57              return PageContext.APPLICATION_SCOPE;
58          }
59          return PageContext.PAGE_SCOPE;
60      }
61  
62      static Level resolveLevel(final Object level) {
63          if (level instanceof Level) {
64              return (Level) level;
65          }
66          if (level instanceof String) {
67              return Level.toLevel((String) level);
68          }
69          return null;
70      }
71  
72      static Log4jTaglibLogger resolveLogger(final Log4jTaglibLoggerContext context, final Object logger,
73                                             final MessageFactory factory) throws JspException {
74          if (logger instanceof Logger) {
75              if (logger instanceof Log4jTaglibLogger) {
76                  return (Log4jTaglibLogger) logger;
77              }
78              if (logger instanceof AbstractLogger) {
79                  if (LOGGER.isInfoEnabled() && !WARNED_FOR.contains(logger)) {
80                      LOGGER.info("Constructing new Log4jTaglibLogger from AbstractLogger {} name and message factory.",
81                              logger.getClass().getName());
82                      WARNED_FOR.add(logger);
83                  }
84                  final AbstractLogger original = (AbstractLogger) logger;
85                  return getLogger(context, original.getName(), original.getMessageFactory());
86              }
87              throw new JspException(
88                      "Log4j Tag Library requires base logging system to extend Log4j AbstractLogger.");
89          }
90          if (logger instanceof String) {
91              return getLogger(context, (String) logger, factory);
92          }
93          throw new JspException("Logger must be of type String or org.apache.logging.log4j.Logger.");
94      }
95  
96      private static Log4jTaglibLogger getLogger(final Log4jTaglibLoggerContext context, final String name,
97                                                 final MessageFactory factory)
98              throws JspException {
99          try {
100             return context.getLogger(name, factory);
101         } catch (final LoggingException e) {
102             throw new JspException(e.getMessage(), e);
103         }
104     }
105 
106     static void setDefaultLogger(final PageContext pageContext, final Log4jTaglibLogger logger) {
107         pageContext.setAttribute(TagUtils.LOGGER_SCOPE_ATTRIBUTE, logger, PageContext.PAGE_SCOPE);
108     }
109 
110     static Log4jTaglibLogger getDefaultLogger(final PageContext pageContext) {
111         return (Log4jTaglibLogger) pageContext.getAttribute(TagUtils.LOGGER_SCOPE_ATTRIBUTE, PageContext.PAGE_SCOPE);
112     }
113 
114     static boolean isEnabled(final Log4jTaglibLogger logger, final Level level, final Marker marker) {
115         if (marker == null) {
116             return logger.isEnabled(level);
117         }
118         return logger.isEnabled(level, marker, (Object) null, null);
119     }
120 }