1 package org.apache.velocity.runtime.log;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import org.apache.velocity.runtime.RuntimeServices;
23
24 /**
25 * Logger used when no other is configured. By default, all messages
26 * will be printed to the System.err output stream.
27 *
28 * @author <a href="mailto:nbubna@apache.org">Nathan Bubna</a>
29 * @version $Id: SystemLogChute.java 463298 2006-10-12 16:10:32Z henning $
30 */
31 public class SystemLogChute implements LogChute
32 {
33 public static final String RUNTIME_LOG_LEVEL_KEY =
34 "runtime.log.logsystem.system.level";
35 public static final String RUNTIME_LOG_SYSTEM_ERR_LEVEL_KEY =
36 "runtime.log.logsystem.system.err.level";
37
38 private int enabled = TRACE_ID;
39 private int errLevel = TRACE_ID;
40
41 public void init(RuntimeServices rs) throws Exception
42 {
43 // look for a level config property
44 String level = (String)rs.getProperty(RUNTIME_LOG_LEVEL_KEY);
45 if (level != null)
46 {
47 // and set it accordingly
48 setEnabledLevel(toLevel(level));
49 }
50
51 // look for an errLevel config property
52 String errLevel = (String)rs.getProperty(RUNTIME_LOG_SYSTEM_ERR_LEVEL_KEY);
53 if (errLevel != null)
54 {
55 setSystemErrLevel(toLevel(errLevel));
56 }
57 }
58
59 protected int toLevel(String level) {
60 if (level.equalsIgnoreCase("debug"))
61 {
62 return DEBUG_ID;
63 }
64 else if (level.equalsIgnoreCase("info"))
65 {
66 return INFO_ID;
67 }
68 else if (level.equalsIgnoreCase("warn"))
69 {
70 return WARN_ID;
71 }
72 else if (level.equalsIgnoreCase("error"))
73 {
74 return ERROR_ID;
75 }
76 else
77 {
78 return TRACE_ID;
79 }
80 }
81
82 protected String getPrefix(int level)
83 {
84 switch (level)
85 {
86 case WARN_ID:
87 return WARN_PREFIX;
88 case INFO_ID:
89 return INFO_PREFIX ;
90 case DEBUG_ID:
91 return DEBUG_PREFIX;
92 case TRACE_ID:
93 return TRACE_PREFIX;
94 case ERROR_ID:
95 return ERROR_PREFIX;
96 default:
97 return INFO_PREFIX;
98 }
99 }
100
101 /**
102 * Logs messages to either std.out or std.err
103 * depending on their severity.
104 *
105 * @param level severity level
106 * @param message complete error message
107 */
108 public void log(int level, String message)
109 {
110 // pass it off
111 log(level, message, null);
112 }
113
114 /**
115 * Logs messages to the system console so long as the specified level
116 * is equal to or greater than the level this LogChute is enabled for.
117 * If the level is equal to or greater than LogChute.ERROR_ID,
118 * messages will be printed to System.err. Otherwise, they will be
119 * printed to System.out. If a java.lang.Throwable accompanies the
120 * message, it's stack trace will be printed to the same stream
121 * as the message.
122 *
123 * @param level severity level
124 * @param message complete error message
125 * @param t the java.lang.Throwable
126 */
127 public void log(int level, String message, Throwable t)
128 {
129 if (!isLevelEnabled(level))
130 {
131 return;
132 }
133
134 String prefix = getPrefix(level);
135 if (level >= this.errLevel)
136 {
137 System.err.print(prefix);
138 System.err.println(message);
139 if (t != null)
140 {
141 System.err.println(t.getMessage());
142 t.printStackTrace();
143 }
144 }
145 else
146 {
147 System.out.print(prefix);
148 System.out.println(message);
149 if (t != null)
150 {
151 System.out.println(t.getMessage());
152 t.printStackTrace(System.out);
153 }
154 }
155 }
156
157 /**
158 * Set the minimum level at which messages will be printed.
159 */
160 public void setEnabledLevel(int level)
161 {
162 this.enabled = level;
163 }
164
165 /**
166 * Returns the current minimum level at which messages will be printed.
167 */
168 public int getEnabledLevel()
169 {
170 return this.enabled;
171 }
172
173 /**
174 * Set the minimum level at which messages will be printed to System.err
175 * instead of System.out.
176 */
177 public void setSystemErrLevel(int level)
178 {
179 this.errLevel = level;
180 }
181
182 /**
183 * Returns the current minimum level at which messages will be printed
184 * to System.err instead of System.out.
185 */
186 public int getSystemErrLevel()
187 {
188 return this.errLevel;
189 }
190
191 /**
192 * This will return true if the specified level
193 * is equal to or higher than the level this
194 * LogChute is enabled for.
195 */
196 public boolean isLevelEnabled(int level)
197 {
198 return (level >= this.enabled);
199 }
200
201 }