Akka系列之Logging

在akka中如何使用log

akka中显示日志不需要第三方jar, 直接使用akka的Logging即可, Logging默认是输出到STDOUT, 当然你也可以使用第三方插件如SLF4J来记录日志, Logging使用的异步方式以此来达到最小的性能损耗.

代码中使用Logging

1import akka.actor.*;
2import akka.event.Logging;
3import akka.event.LoggingAdapter;
4
5
6class MyActor extends UntypedActor {
7  LoggingAdapter log = Logging.getLogger(getContext().system(), this);
8  @Override
9  public void preStart() {
10    log.debug("Starting");
11  }
12  @Override
13  public void preRestart(Throwable reason, Option<Object> message) {
14    log.error(reason, "Restarting due to [{}] when processing [{}]",
15      reason.getMessage(), message.isDefined() ? message.get() : "");
16}
17  public void onReceive(Object message) {
18    if (message.equals("test")) {
19      log.info("Received test");
20    } else {
21      log.warning("Received unknown message: {}", message);
22    }
23} }

Dead letters的log

akka中默认dead letters会以info的形式输出.你可以调整显示多少dead letter, 并在之后就不再显示这些log. 另外在程序shutdown时显示相应的dead letters.

1akka {
2  log-dead-letters = 10
3  log-dead-letters-during-shutdown = on
4}

调整logging的级别

1 akka {
2  loglevel = "DEBUG"
3}

启动时显示相应的config

1akka {
2  # Log the complete configuration at INFO level when the actor system is started.
3  # This is useful when you are uncertain of what configuration is used.
4  log-config-on-start = on
5}

如果希望非常详细的显示所有接受到的消息

1akka { 
2    actor {
3        debug {
4             # enable DEBUG logging of all AutoReceiveMessages (Kill, PoisonPill et.c.)
5            autoreceive = on
6        }
7    } 
8    
9}

使用SLF4J

• maven中新增配置

  <!-- https://mvnrepository.com/artifact/com.typesafe.akka/akka-slf4j_2.11 -->

  1<dependency>
  2    <groupId>com.typesafe.akka</groupId>
  3    <artifactId>akka-slf4j_2.11</artifactId>
  4    <version>2.4.17</version>
  5</dependency>
  6<!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-core -->
  

  <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-core</artifactId> <version>1.1.7</version> </dependency> <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic --> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> <version>1.1.7</version> </dependency>

• resources/目录下新增logback.xml

  <?xml version="1.0" encoding="UTF-8"?> <configuration> <!-- 文件输出 --> <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender"> <encoder> <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern> </encoder>

  1    <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
  2        <fileNamePattern>logs\akka.%d{yyyy-MM-dd}.%i.log</fileNamePattern>
  3        <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
  4            <maxFileSize>50MB</maxFileSize>
  5        </timeBasedFileNamingAndTriggeringPolicy>
  6    </rollingPolicy>
  7</appender>
  8<!-- 控制台输出 -->   
  9<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
  10   <!-- 日志输出编码 -->  
  11   <Encoding>UTF-8</Encoding>   
  12    <layout class="ch.qos.logback.classic.PatternLayout">   
  13         <!--格式化输出：%d表示日期，%thread表示线程名，%-5level：级别从左显示5个字符宽度%msg：日志消息，%n是换行符--> 
  14        <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>   
  15    </layout>
  16</appender>
  17
  18<root level="DEBUG">
  19    <appender-ref ref="FILE" />
  20    <appender-ref ref="STDOUT"/>
  21</root>
  

  </configuration>

• 程序中使用

  private Logger log = LoggerFactory.getLogger(XXX.class);