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 * Base interface that logging systems need to implement. This
26 * is the blessed descendant of the old LogSystem interface.
27 *
28 * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
29 * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
30 * @author <a href="mailto:nbubna@apache.org">Nathan Bubna</a>
31 * @version $Id: LogChute.java 685685 2008-08-13 21:43:27Z nbubna $
32 * @since 1.5
33 */
34 public interface LogChute
35 {
36 /** Prefix string for trace messages. */
37 String TRACE_PREFIX = " [trace] ";
38
39 /** Prefix string for debug messages. */
40 String DEBUG_PREFIX = " [debug] ";
41
42 /** Prefix string for info messages. */
43 String INFO_PREFIX = " [info] ";
44
45 /** Prefix string for warn messages. */
46 String WARN_PREFIX = " [warn] ";
47
48 /** Prefix string for error messages. */
49 String ERROR_PREFIX = " [error] ";
50
51 /** ID for trace messages. */
52 int TRACE_ID = -1;
53
54 /** ID for debug messages. */
55 int DEBUG_ID = 0;
56
57 /** ID for info messages. */
58 int INFO_ID = 1;
59
60 /** ID for warning messages. */
61 int WARN_ID = 2;
62
63 /** ID for error messages. */
64 int ERROR_ID = 3;
65
66 /**
67 * Initializes this LogChute.
68 * @param rs
69 * @throws Exception
70 */
71 void init(RuntimeServices rs) throws Exception;
72
73 /**
74 * Send a log message from Velocity.
75 * @param level
76 * @param message
77 */
78 void log(int level, String message);
79
80 /**
81 * Send a log message from Velocity along with an exception or error
82 * @param level
83 * @param message
84 * @param t
85 */
86 void log(int level, String message, Throwable t);
87
88 /**
89 * Tell whether or not a log level is enabled.
90 * @param level
91 * @return True if a level is enabled.
92 */
93 boolean isLevelEnabled(int level);
94
95 }