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 java.io.PrintStream;
23 import org.apache.velocity.runtime.RuntimeServices;
24
25 /**
26 * Logger used when no other is configured. By default, all messages
27 * will be printed to the System.err output stream.
28 *
29 * @author <a href="mailto:nbubna@apache.org">Nathan Bubna</a>
30 * @version $Id: SystemLogChute.java 730039 2008-12-30 03:53:19Z byron $
31 * @since 1.5
32 */
33 public class SystemLogChute implements LogChute
34 {
35 public static final String RUNTIME_LOG_LEVEL_KEY =
36 "runtime.log.logsystem.system.level";
37 public static final String RUNTIME_LOG_SYSTEM_ERR_LEVEL_KEY =
38 "runtime.log.logsystem.system.err.level";
39
40 private int enabled = WARN_ID;
41 private int errLevel = TRACE_ID;
42
43 public void init(RuntimeServices rs) throws Exception
44 {
45 // look for a level config property
46 String level = (String)rs.getProperty(RUNTIME_LOG_LEVEL_KEY);
47 if (level != null)
48 {
49 // and set it accordingly
50 setEnabledLevel(toLevel(level));
51 }
52
53 // look for an errLevel config property
54 String errLevel = (String)rs.getProperty(RUNTIME_LOG_SYSTEM_ERR_LEVEL_KEY);
55 if (errLevel != null)
56 {
57 setSystemErrLevel(toLevel(errLevel));
58 }
59 }
60
61 protected int toLevel(String level) {
62 if (level.equalsIgnoreCase("debug"))
63 {
64 return DEBUG_ID;
65 }
66 else if (level.equalsIgnoreCase("info"))
67 {
68 return INFO_ID;
69 }
70 else if (level.equalsIgnoreCase("warn"))
71 {
72 return WARN_ID;
73 }
74 else if (level.equalsIgnoreCase("error"))
75 {
76 return ERROR_ID;
77 }
78 else
79 {
80 return TRACE_ID;
81 }
82 }
83
84 protected String getPrefix(int level)
85 {
86 switch (level)
87 {
88 case WARN_ID:
89 return WARN_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 case INFO_ID:
97 default:
98 return INFO_PREFIX;
99 }
100 }
101
102 /**
103 * Logs messages to either std.out or std.err
104 * depending on their severity.
105 *
106 * @param level severity level
107 * @param message complete error message
108 */
109 public void log(int level, String message)
110 {
111 // pass it off
112 log(level, message, null);
113 }
114
115 /**
116 * Logs messages to the system console so long as the specified level
117 * is equal to or greater than the level this LogChute is enabled for.
118 * If the level is equal to or greater than LogChute.ERROR_ID,
119 * messages will be printed to System.err. Otherwise, they will be
120 * printed to System.out. If a java.lang.Throwable accompanies the
121 * message, it's stack trace will be printed to the same stream
122 * as the message.
123 *
124 * @param level severity level
125 * @param message complete error message
126 * @param t the java.lang.Throwable
127 */
128 public void log(int level, String message, Throwable t)
129 {
130 if (!isLevelEnabled(level))
131 {
132 return;
133 }
134
135 String prefix = getPrefix(level);
136 if (level >= this.errLevel)
137 {
138 write(System.err, prefix, message, t);
139 }
140 else
141 {
142 write(System.out, prefix, message, t);
143 }
144 }
145
146 protected void write(PrintStream stream, String prefix, String message, Throwable t)
147 {
148 stream.print(prefix);
149 stream.println(message);
150 if (t != null)
151 {
152 stream.println(t.getMessage());
153 t.printStackTrace(stream);
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 }