1 /*
2 * Copyright 2006-2012 smartics, Kronseder & Reiner GmbH
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package de.smartics.maven.util;
17
18 import java.lang.reflect.Method;
19 import java.util.logging.Level;
20
21 import org.apache.maven.plugin.logging.Log;
22
23 /**
24 * Utility class for configuring loggers in Maven.
25 *
26 * @author <a href="mailto:robert.reiner@smartics.de">Robert Reiner</a>
27 * @version $Revision:591 $
28 */
29 public final class LoggingUtils
30 {
31 // ********************************* Fields *********************************
32
33 // --- constants ------------------------------------------------------------
34
35 // --- members --------------------------------------------------------------
36
37 // ****************************** Initializer *******************************
38
39 // ****************************** Constructors ******************************
40
41 /**
42 * Utility class pattern.
43 */
44 private LoggingUtils()
45 {
46 }
47
48 // ****************************** Inner Classes *****************************
49
50 // ********************************* Methods ********************************
51
52 // --- init -----------------------------------------------------------------
53
54 // --- get&set --------------------------------------------------------------
55
56 // --- business -------------------------------------------------------------
57
58 /**
59 * Configures the Java logging system.
60 *
61 * @param log the Maven logger.
62 * @throws NullPointerException if <code>log</code> is <code>null</code>.
63 */
64 public static void configureLogger(final Log log, final String logLevel)
65 {
66 final String newLevel;
67 if (!isBlank(logLevel))
68 {
69 newLevel = logLevel;
70 if (log.isDebugEnabled())
71 {
72 log.debug("Using configured level " + newLevel);
73 }
74 }
75 else
76 {
77 newLevel = determineLevel(log);
78 if (log.isDebugEnabled())
79 {
80 log.debug("Using Maven level " + newLevel);
81 }
82 }
83 configure(log, newLevel);
84 }
85
86 private static void configure(final Log log, final String newLevel)
87 {
88 if (isAvailable("org.apache.log4j.Logger"))
89 {
90 runLog4jConfigure(log, newLevel);
91 }
92
93 new SunLoggerConfigurator().configure(log, newLevel);
94 }
95
96 private static void runLog4jConfigure(final Log log, final String newLevel)
97 {
98 try
99 {
100 final Class<?> clazz =
101 Class.forName("de.smartics.maven.util.log4j.Log4jConfigurator");
102 final Object instance = clazz.newInstance();
103 final Method method =
104 clazz.getMethod("configure", Log.class, String.class);
105 method.invoke(instance, log, newLevel);
106 }
107 catch (final Exception e)
108 {
109 if (log.isWarnEnabled())
110 {
111 log.warn("Cannot configure log4j logger.", e);
112 }
113 }
114 }
115
116 private static boolean isAvailable(final String className)
117 {
118 try
119 {
120 Class.forName(className);
121 return true;
122 }
123 catch (final Exception e)
124 {
125 return false;
126 }
127 }
128
129 /**
130 * Checks if the given string is blank or not.
131 * <p>
132 * Implemented to not require to include commons-lang.
133 * </p>
134 *
135 * @param value the value to check.
136 * @return <code>true</code> if the <code>value</code> is <code>null</code>,
137 * empty or contains only whitespaces.
138 */
139 private static boolean isBlank(final String logLevel)
140 {
141 return (logLevel == null || "".equals(logLevel.trim()));
142 }
143
144 /**
145 * Determines the level of the Maven logger.
146 *
147 * @param log the Maven logger to request the log level from.
148 * @return the log level for Java logging as {@link String}.
149 */
150 private static String determineLevel(final Log log)
151 {
152 if (log.isDebugEnabled())
153 {
154 return Level.FINEST.toString();
155 }
156 else if (log.isInfoEnabled())
157 {
158 return Level.INFO.toString();
159 }
160 else if (log.isWarnEnabled())
161 {
162 return Level.WARNING.toString();
163 }
164 else
165 {
166 return Level.SEVERE.toString();
167 }
168 }
169
170 // --- object basics --------------------------------------------------------
171
172 }