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 {@code System.out} and {@code 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 /**
60 * Creates a new instance of the default log.
61 * @return A new instance of the default log.
62 */
63 public static Log createDefault() {
64 return new DefaultLog();
65 }
66
67 /** The level at which we will write messages */
68 private Level level;
69
70 private DefaultLog() {
71 try {
72 level = StringUtils.isNotEmpty(System.getenv(ENV_VAR)) ?
73 Level.valueOf(System.getenv(ENV_VAR).toUpperCase()) : Level.INFO;
74 } catch (IllegalArgumentException e) {
75 level = Level.INFO;
76 log(Level.WARN, "Invalid log level set in environment", e);
77 }
78 }
79
80 /**
81 * Sets the level. Log messages below the specified level will
82 * not be written to the log.
83 * @param level the level to use when writing messages.
84 */
85 public void setLevel(final Level level) {
86 this.level = level;
87 }
88
89 /**
90 * Gets the level we are writing at.
91 * @return the level we are writing at.
92 */
93 public Level getLevel() {
94 return level;
95 }
96
97 @Override
98 public void log(final Level level, final String msg) {
99 if (isEnabled(level)) {
100 switch (level) {
101 case DEBUG:
102 case INFO:
103 case WARN:
104 System.out.format("%s: %s%n", level, msg);
105 break;
106 case ERROR:
107 System.err.format("%s: %s%n", level, msg);
108 break;
109 case OFF:
110 default:
111 break;
112 }
113 }
114 }
115 }