爪哇七月至SLF4J大桥

Question

我目前观察到第三方库（即restfb）正在使用java。util。记录日志，我看到这些日志最终会出现在STDOUT中，即使我的日志中没有配置SLF4J控制台追加器。xml。我的类路径中还有jul-to-slf4j桥。安装网桥时，jul-to-slf4j网桥是否只记录到logback配置的Appender，还是也记录到stdout

Answer 1

我的解决方案：

SLF4JBridgeHandler.install();
java.util.logging.LogManager.getLogManager().getLogger("").setLevel( Level.INFO);

将jul-to-slf4j放在您的应用程序库或glassfish库中，这些库会将jul重定向到slf4j（在我的例子中是LOG4J）

然后，对于泽西岛，您可以执行以下操作：

<logger name="com.sun.jersey" additivity="false">
    <level value="WARN" />
    <appender-ref ref="JVM" />
    <appender-ref ref="CONSOLE" />
</logger>   

<logger name="com.sun.common.util.logging" additivity="false">
    <level value="ERROR" />
    <appender-ref ref="JVM" />
    <appender-ref ref="CONSOLE" />
</logger>

最后一个配置是避免被其他记录器污染

Answer 2

这个解决方案看起来不错（考虑到七月桥接的情况），对我来说很有效，因为我只需要在日志中写下所有内容。groovy文件

1. （如果您根本没有使用logback.groovy配置或logback，当然您必须将逻辑部分放入某个类中（例如class MyApp { static { /* log init code here */ } ... }））

2. src/logback。groovy：

    import org.slf4j.bridge.SLF4JBridgeHandler
    import ch.qos.logback.classic.jul.LevelChangePropagator
   
    // for debug: just to see it in case something is logging/initialized before
    System.out.println( 'my myapp logback.groovy is loading' )
   
    // see also: http://logback.qos.ch/manual/configuration.html#LevelChangePropagator
    // performance speedup for redirected JUL loggers
    def lcp = new LevelChangePropagator()
    lcp.context = context
    lcp.resetJUL = true
    context.addListener(lcp)
   
    // needed only for the JUL bridge: http://stackoverflow.com/a/9117188/1915920
    java.util.logging.LogManager.getLogManager().reset()
    SLF4JBridgeHandler.removeHandlersForRootLogger()
    SLF4JBridgeHandler.install()
    java.util.logging.Logger.getLogger( "global" ).setLevel( java.util.logging.Level.FINEST )
   
    def logPattern = "%date |%.-1level| [%thread] %20.20logger{10}|  %msg%n"
   
    appender("STDOUT", ConsoleAppender) {
        encoder(PatternLayoutEncoder) {
            pattern = logPattern
        }
    }
   
    /*// outcommenting in dev will not create dummy empty file
    appender("ROLLING", RollingFileAppender) {  // prod
        encoder(PatternLayoutEncoder) {
            Pattern = "%date %.-1level [%thread] %20.20logger{10}  %msg%n"
        }
        rollingPolicy(TimeBasedRollingPolicy) {
            FileNamePattern = "${WEBAPP_DIR}/log/orgv-fst-gwt-%d{yyyy-MM-dd}.zip"
        }
    }
    */
   
    appender("FILE", FileAppender) {  // dev
   
        // log to myapp/tmp (independent of running in dev/prod or junit mode:
   
        //System.out.println( 'DEBUG: WEBAPP_DIR env prop:  "."='+new File('.').absolutePath+',  \${WEBAPP_DIR}=${WEBAPP_DIR},  env=' + System.getProperty( "WEBAPP_DIR" ))
        String webappDirName = "war"
        if ( new File( "./../"+webappDirName ).exists() )  // we are not running within a junit test
            file = "../tmp/myapp.log"
        else  // junit test
            file = "tmp/myapp-junit-tests.log"
   
        encoder(PatternLayoutEncoder) { pattern = logPattern }
    }
   
    // without JUL bridge:
    //root(WARN, ["STDOUT", "ROLLING"])  // prod
    //root(DEBUG, ["STDOUT", "FILE"])  // dev
   
    // with JUL bridge: (workaround: see links above)
    def rootLvl = WARN
    root(TRACE, [/*"STDOUT",*/ "FILE"])
    // I manually added all "root package dirs" I know my libs are based on to apply
    // the root level to the second "package dir level" at least
    // depending on your libs used you could remove entries, but I would recommend
    // to add common entries instead (feel free to edit this post if you like to
    // enhance it anywhere)
    logger( "antlr", rootLvl )
    logger( "de", rootLvl )
    logger( "ch", rootLvl )
    logger( "com", rootLvl )
    logger( "java", rootLvl )
    logger( "javassist", rootLvl )
    logger( "javax", rootLvl )
    logger( "junit", rootLvl )
    logger( "groovy", rootLvl )
    logger( "net", rootLvl )
    logger( "org", rootLvl )
    logger( "sun", rootLvl )
   
   
    // my logger setup
   
    logger( "myapp", DEBUG )
   
   
    //logger( "org.hibernate.SQL", DEBUG )  // debug: log SQL statements in DEBUG mode
    //logger( "org.hibernate.type", TRACE )  // debug: log JDBC parameters in TRACE mode
    logger( "org.hibernate.type.BasicTypeRegistry", WARN )  // uninteresting
   
    scan("30 seconds")  // reload/apply-on-change config every x sec
   

（建议我使用，因为您可以使用Java代码变量/函数，如您在这里看到的，例如，SLF4JBridgeHandler或关于webappDirName的log dir）

（使文件保持完整，因为它给人一个更好的印象，即如何设置所有内容或将其作为起始模板）

（可能与某人有关-我的环境：slf4j 1.7.5、logback 1.1.2、groovy 2.1.9）

Answer 3

如SLF4JBridgeHandler的javadocs中所述，您可以通过调用以下命令以编程方式安装SLF4JBridgeHandler：

 // Optionally remove existing handlers attached to j.u.l root logger
 SLF4JBridgeHandler.removeHandlersForRootLogger();  // (since SLF4J 1.6.5)

 // add SLF4JBridgeHandler to j.u.l's root logger, should be done once during
 // the initialization phase of your application
 SLF4JBridgeHandler.install();

或者通过日志记录。性质

 // register SLF4JBridgeHandler as handler for the j.u.l. root logger
 handlers = org.slf4j.bridge.SLF4JBridgeHandler

至于性能，关于jul-to-slf4j桥的一节讨论了这个问题。本质上，因为您已经在使用logback，所以启用LevelChangePropagator应该会产生良好的性能，而不管负载如何

Answer 4

我使用SLF4J和new Postgres driver 42.0.0

根据changelog它使用java。util。伐木

有驱动程序日志就足够了：

1. 添加jul-to-slf4j bridge：

   <dependency>
       <groupId>org.slf4j</groupId>
       <artifactId>jul-to-slf4j</artifactId>
       <version>${slf4j.version}</version>
       <scope>runtime</scope>
   </dependency>
   

2. 添加logback。xml（logbacktest.xml）

   <contextListener class="ch.qos.logback.classic.jul.LevelChangePropagator">
       <resetJUL>true</resetJUL>
   </contextListener>
   
   <appender ...
   
   <logger name="org.postgresql" level="trace"/>
   

3. 外接程序代码

   static {
       SLF4JBridgeHandler.install();
   }
   

Answer 5

你需要打电话给^{}。您还需要在java中启用根记录器的所有日志级别（原因见下面的摘录）。util。记录并删除默认控制台追加器

This handler will redirect jul logging to SLF4J. However, only logs enabled in j.u.l. will be redirected. For example, if a log statement invoking a j.u.l. logger disabled that statement, by definition, will not reach any SLF4JBridgeHandler instance and cannot be redirected.

整个过程可以这样完成

import java.util.logging.Logger;
import org.slf4j.bridge.SLF4JBridgeHandler;

SLF4JBridgeHandler.removeHandlersForRootLogger();
SLF4JBridgeHandler.install();
Logger.getLogger("").setLevel(Level.FINEST); // Root logger, for example.

出于性能原因，您可以将级别设置为高于finest的级别，但是如果不首先在java.util.logging中启用这些日志，您将无法打开这些日志（出于上述摘录中提到的原因）