1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one *
3 * or more contributor license agreements. See the NOTICE file *
4 * distributed with this work for additional information *
5 * regarding copyright ownership. The ASF licenses this file *
6 * to you under the Apache License, Version 2.0 (the *
7 * "License"); you may not use this file except in compliance *
8 * with the License. You may obtain a copy of the License at *
9 * *
10 * http://www.apache.org/licenses/LICENSE-2.0 *
11 * *
12 * Unless required by applicable law or agreed to in writing, *
13 * software distributed under the License is distributed on an *
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
15 * KIND, either express or implied. See the License for the *
16 * specific language governing permissions and limitations *
17 * under the License. *
18 */
19 package org.apache.rat.utils;
20
21 import org.apache.commons.lang3.StringUtils;
22
23 /**
24 * A default implementation of Log that writes to System.out and System.err
25 */
26 public final class DefaultLog implements Log {
27 /**
28 * The environment variable to set the default log level that Rat should log at.
29 * If not specified INFO is used.
30 * @see #setLevel(Level)
31 */
32 public static final String ENV_VAR = DefaultLog.class.getName();
33
34 /**
35 * The instance of the default log.
36 */
37 private static Log instance = new DefaultLog();
38
39 /**
40 * Retrieves teh DefaultLog instance.
41 * @return the Default log instance.
42 */
43 public static Log getInstance() {
44 return instance;
45 }
46
47 /**
48 * Sets the default log instance.
49 * If not set an instance of DefaultLog will be returned
50 * @param newInstance a Log to use as the default.
51 * @return the old instance.
52 */
53 public static Log setInstance(final Log newInstance) {
54 Log result = instance;
55 instance = newInstance == null ? new DefaultLog() : newInstance;
56 return result;
57 }
58
59 /** The level at which we will write messages */
60 private Level level;
61
62 private DefaultLog() {
63 try {
64 level = StringUtils.isNotEmpty(System.getenv(ENV_VAR)) ?
65 Level.valueOf(System.getenv(ENV_VAR).toUpperCase()) : Level.INFO;
66 } catch (IllegalArgumentException e) {
67 level = Level.INFO;
68 log(Level.WARN, "Invalid log level set in environment", e);
69 }
70 }
71
72 /**
73 * Sets the level. Log messages below the specified level will
74 * not be written to the log.
75 * @param level the level to use when writing messages.
76 */
77 public void setLevel(final Level level) {
78 this.level = level;
79 }
80
81 /**
82 * Gets the level we are writing at.
83 * @return the level we are writing at.
84 */
85 public Level getLevel() {
86 return level;
87 }
88
89 @Override
90 public void log(final Level level, final String msg) {
91 if (isEnabled(level)) {
92 switch (level) {
93 case DEBUG:
94 case INFO:
95 case WARN:
96 System.out.format("%s: %s%n", level, msg);
97 break;
98 case ERROR:
99 System.err.format("%s: %s%n", level, msg);
100 break;
101 case OFF:
102 default:
103 break;
104 }
105 }
106 }
107 }