发表于|更新于|java
|总字数:847|阅读时长:4分钟|浏览量:|
java调试代码不再用system.out.println();，用完再删除，想用了再添加。
用日志直接打印。
两对好基友：Commons Logging加Log4j，SLF4J加Logback。
两对好基友看不起java内置的JDK Logging
JDK Logging
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
| package _22javacoreclass;
import java.util.logging.Logger;
public class Main5{
public static void main(String[] args) {
Logger logger = Logger.getGlobal();
/**JDK Logging */
//默认info，info以下不打印信息
//不常用
//严重
logger.severe("process will be terminated...");
//警告
logger.warning("memory is running out...");
//信息
logger.info("start process...");
//config
logger.config("ignored.");
//fine
logger.fine("ignored.");
//finer
logger.finer("ignored.");
//finest
logger.finest("ignored.");
}
}
|
Commons Logging加Log4j，需要增加log4j2.xml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
| package _22javacoreclass;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
public class Main5{
public static void main(String[] args) {
/**Commons Logging */
Log log = LogFactory.getLog(Main5.class);
log.fatal("fatal...");
log.error("error.");
log.warn("warn...");
log.info("info.");
log.debug("debug...");
log.trace("trace.");
/**Log4j */
// Commons Logging自动发现并调用|好基友
}
}
|
log4j2.xml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
| <?xml version="1.0" encoding="UTF-8"?>
<Configuration>
<Properties>
<!-- 定义日志格式 -->
<Property name="log.pattern">%d{MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36}%n%msg%n%n</Property>
<!-- 定义文件名变量 -->
<Property name="file.err.filename">log/err.log</Property>
<Property name="file.err.pattern">log/err.%i.log.gz</Property>
</Properties>
<!-- 定义Appender，即目的地 -->
<Appenders>
<!-- 定义输出到屏幕 -->
<Console name="console" target="SYSTEM_OUT">
<!-- 日志格式引用上面定义的log.pattern -->
<PatternLayout pattern="${log.pattern}" />
</Console>
<!-- 定义输出到文件,文件名引用上面定义的file.err.filename -->
<RollingFile name="err" bufferedIO="true" fileName="${file.err.filename}" filePattern="${file.err.pattern}">
<PatternLayout pattern="${log.pattern}" />
<Policies>
<!-- 根据文件大小自动切割日志 -->
<SizeBasedTriggeringPolicy size="1 MB" />
</Policies>
<!-- 保留最近10份 -->
<DefaultRolloverStrategy max="10" />
</RollingFile>
</Appenders>
<Loggers>
<Root level="info">
<!-- 对info级别的日志，输出到console -->
<AppenderRef ref="console" level="info" />
<!-- 对error级别的日志，输出到err，即上面定义的RollingFile -->
<AppenderRef ref="err" level="error" />
</Root>
</Loggers>
</Configuration>
|
SLF4J加Logback，需要增加logback.xml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
| package _22javacoreclass;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
//SLF4J和Logback好基友
public class Main51 {
public static void main(String[] args) {
Logger logger = LoggerFactory.getLogger(Main51.class);
logger.error("error.");
logger.warn("warn...");
logger.info("info.");
logger.debug("debug...");
logger.trace("trace.");
}
}
|
logback.xml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
| <?xml version="1.0" encoding="UTF-8"?>
<configuration>
<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
<charset>utf-8</charset>
</encoder>
<file>log/output.log</file>
<rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
<fileNamePattern>log/output.log.%i</fileNamePattern>
</rollingPolicy>
<triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
<MaxFileSize>1MB</MaxFileSize>
</triggeringPolicy>
</appender>
<root level="INFO">
<appender-ref ref="CONSOLE" />
<appender-ref ref="FILE" />
</root>
</configuration>
|
