1 /*
2 * Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24 */
25
26
27 package java.util.logging;
28
29 import java.io.*;
30 import java.time.ZoneId;
31 import java.time.ZonedDateTime;
32 import jdk.internal.logger.SurrogateLogger;
33
34 /**
35 * Print a brief summary of the {@code LogRecord} in a human readable
36 * format. The summary will typically be 1 or 2 lines.
37 *
38 * <p>
39 * <a id="formatting">
40 * <b>Configuration:</b></a>
41 * The {@code SimpleFormatter} is initialized with the format string
42 * specified in the {@systemProperty java.util.logging.SimpleFormatter.format}
43 * property to {@linkplain #format(LogRecord) format} the log messages.
44 * This property can be defined
45 * in the {@linkplain LogManager#getProperty logging properties}
46 * configuration file
47 * or as a system property. If this property is set in both
48 * the logging properties and system properties,
49 * the format string specified in the system property will be used.
50 * If this property is not defined or the given format string
51 * is {@linkplain java.util.IllegalFormatException illegal},
52 * the default format is implementation-specific.
53 *
54 * @since 1.4
55 * @see java.util.Formatter
56 */
57
58 public class SimpleFormatter extends Formatter {
59
60 // format string for printing the log record
61 static String getLoggingProperty(String name) {
62 return LogManager.getLogManager().getProperty(name);
63 }
64
65 private final String format =
66 SurrogateLogger.getSimpleFormat(SimpleFormatter::getLoggingProperty);
67
68 /**
69 * Create a {@code SimpleFormatter}.
70 */
71 public SimpleFormatter() {}
72
73 /**
74 * Format the given LogRecord.
75 * <p>
76 * The formatting can be customized by specifying the format string
77 * in the <a href="#formatting">
78 * {@code java.util.logging.SimpleFormatter.format}</a> property.
79 * The given {@code LogRecord} will be formatted as if by calling:
80 * <pre>
81 * {@link String#format String.format}(format, date, source, logger, level, message, thrown);
82 * </pre>
83 * where the arguments are:<br>
84 * <ol>
85 * <li>{@code format} - the {@link java.util.Formatter
86 * java.util.Formatter} format string specified in the
87 * {@code java.util.logging.SimpleFormatter.format} property
88 * or the default format.</li>
89 * <li>{@code date} - a {@link ZonedDateTime} object representing
90 * {@linkplain LogRecord#getInstant() event time} of the log record
91 * in the {@link ZoneId#systemDefault()} system time zone.</li>
92 * <li>{@code source} - a string representing the caller, if available;
93 * otherwise, the logger's name.</li>
94 * <li>{@code logger} - the logger's name.</li>
95 * <li>{@code level} - the {@linkplain Level#getLocalizedName
96 * log level}.</li>
97 * <li>{@code message} - the formatted log message
98 * returned from the {@link Formatter#formatMessage(LogRecord)}
99 * method. It uses {@link java.text.MessageFormat java.text}
100 * formatting and does not use the {@code java.util.Formatter
101 * format} argument.</li>
102 * <li>{@code thrown} - a string representing
103 * the {@linkplain LogRecord#getThrown throwable}
104 * associated with the log record and its backtrace
105 * beginning with a newline character, if any;
106 * otherwise, an empty string.</li>
107 * </ol>
108 *
109 * <p>Some example formats:<br>
110 * <ul>
111 * <li> {@code java.util.logging.SimpleFormatter.format="%4$s: %5$s [%1$tc]%n"}
112 * <p>This prints 1 line with the log level ({@code 4$}),
113 * the log message ({@code 5$}) and the timestamp ({@code 1$}) in
114 * a square bracket.
115 * <pre>
116 * WARNING: warning message [Tue Mar 22 13:11:31 PDT 2011]
117 * </pre></li>
118 * <li> {@code java.util.logging.SimpleFormatter.format="%1$tc %2$s%n%4$s: %5$s%6$s%n"}
119 * <p>This prints 2 lines where the first line includes
120 * the timestamp ({@code 1$}) and the source ({@code 2$});
121 * the second line includes the log level ({@code 4$}) and
122 * the log message ({@code 5$}) followed by the throwable
123 * and its backtrace ({@code 6$}), if any:
124 * <pre>
125 * Tue Mar 22 13:11:31 PDT 2011 MyClass fatal
126 * SEVERE: several message with an exception
127 * java.lang.IllegalArgumentException: invalid argument
128 * at MyClass.mash(MyClass.java:9)
129 * at MyClass.crunch(MyClass.java:6)
130 * at MyClass.main(MyClass.java:3)
131 * </pre></li>
132 * <li> {@code java.util.logging.SimpleFormatter.format="%1$tb %1$td, %1$tY %1$tl:%1$tM:%1$tS %1$Tp %2$s%n%4$s: %5$s%n"}
133 * <p>This prints 2 lines similar to the example above
134 * with a different date/time formatting and does not print
135 * the throwable and its backtrace:
136 * <pre>
137 * Mar 22, 2011 1:11:31 PM MyClass fatal
138 * SEVERE: several message with an exception
139 * </pre></li>
140 * <li> {@code java.util.logging.SimpleFormatter.format="%1$tb %1$td, %1$tY %1$tl:%1$tM:%1$tS.%1$tN %1$Tp %2$s%n%4$s: %5$s%6$s%n"}
141 * <p>Since JDK 9, {@code java.util.logging} uses {@link
142 * java.time.Clock#systemUTC() java.time} to create more precise time
143 * stamps.
144 * The format above can be used to add a {@code .%1$tN} to the
145 * date/time formatting so that nanoseconds will also be printed:
146 * <pre>
147 * Feb 06, 2015 5:33:10.279216000 PM example.Main main
148 * INFO: This is a test
149 * </pre></li>
150 * </ul>
151 * <p>This method can also be overridden in a subclass.
152 * It is recommended to use the {@link Formatter#formatMessage}
153 * convenience method to localize and format the message field.
154 *
155 * @param record the log record to be formatted.
156 * @return a formatted log record
157 */
158 @Override
159 public String format(LogRecord record) {
160 ZonedDateTime zdt = ZonedDateTime.ofInstant(
161 record.getInstant(), ZoneId.systemDefault());
162 String source;
163 if (record.getSourceClassName() != null) {
164 source = record.getSourceClassName();
165 if (record.getSourceMethodName() != null) {
166 source += " " + record.getSourceMethodName();
167 }
168 } else {
169 source = record.getLoggerName();
170 }
171 String message = formatMessage(record);
172 String throwable = "";
173 if (record.getThrown() != null) {
174 StringWriter sw = new StringWriter();
175 PrintWriter pw = new PrintWriter(sw);
176 pw.println();
177 record.getThrown().printStackTrace(pw);
178 pw.close();
179 throwable = sw.toString();
180 }
181 return String.format(format,
182 zdt,
183 source,
184 record.getLoggerName(),
185 record.getLevel().getLocalizedLevelName(),
186 message,
187 throwable);
188 }
189 }