java 日志处理

import org.apache.commons.logging.Log;  
import org.apache.commons.logging.LogFactory;  
public class A {  
    private static Log logger = LogFactory.getLog(A.class);  
} 

import org.slf4j.Logger;  
import org.slf4j.LoggerFactory;  
public class A {  
      private static Logger logger = LoggerFactory.getLogger(Test.class); 
}  

jcl -- jcl-over-slf4j.jar --- (redirect) ---> SLF4j ---> slf4j-log4j12-version.jar ---> log4j.jar ---> 输出日志

import javax.servlet.ServletContextEvent;

import org.slf4j.bridge.SLF4JBridgeHandler;
import org.springframework.web.context.ContextLoaderListener;

public class SystemListener extends ContextLoaderListener {

    @Override
    public void contextInitialized(ServletContextEvent event) {
        super.contextInitialized(event);
        /******** jul to slf4j *********/
        SLF4JBridgeHandler.install();
    }

    @Override
    public void contextDestroyed(ServletContextEvent event) {
        super.contextDestroyed(event);
        /******** jul to slf4j *********/
        SLF4JBridgeHandler.uninstall();
    }

}

public final class Logger implements org.slf4j.Logger, LocationAwareLogger,
AppenderAttachable<ILoggingEvent>, Serializable {
}

<?xml version="1.0" encoding="UTF-8" ?>
<configuration>
    <!-- 控制台输出日志 -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <layout class="ch.qos.logback.classic.PatternLayout">
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{60} - %msg%n</pattern>
        </layout>
    </appender>
    <!-- 文件输出日志 (文件大小策略进行文件输出，超过指定大小对文件备份) -->
    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <File>${logCatolog}</File>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <FileNamePattern>${logCatolog}.%d{yyMMdd}</FileNamePattern>
            <!-- keep 60 days worth of history -->
            <MaxHistory>60</MaxHistory>
        </rollingPolicy>
        <layout class="ch.qos.logback.classic.PatternLayout">
            <Pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</Pattern>
        </layout>
    </appender>
     
    <root level="ERROR">
        <appender-ref ref="STDOUT" />
        <appender-ref ref="FILE" />
    </root>
    <!--这里指定logger name 是为jmx设置日志级别做铺垫 -->
    <logger name="com.pptv">
        <level value="DEBUG" />
    </logger>
 
    <!--mybatis -->
    <logger name="jdbc.sqltiming" level="INFO" />
</configuration>

import java.util.UUID;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;  

public class Test {

    private static Logger logger = LoggerFactory.getLogger(Test.class);
    
    private static ThreadPoolExecutor pool;
    static{
        pool =  new ThreadPoolExecutor(5, 10,
                60L, TimeUnit.SECONDS,
                new ArrayBlockingQueue<Runnable>(100));
    }

    public static void main(String[] args) {
        for(int i=0; i<20; i++){
            pool.submit(new Runnable(){

                public void run() {
                    MDC.put("REQUEST_ID", UUID.randomUUID().toString().replace("-", ""));
                    logger.info("this is test message");
                    MDC.remove("REQUEST_ID");
                }
                
            });
        }
        

    }
}

    <appender name="FILE"
        class="ch.qos.logback.core.rolling.RollingFileAppender">
        <File>D:\\logs\\sports\\log.log</File>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <FileNamePattern>D:\\logs\\sports\\log.log.%d{yyMMdd}</FileNamePattern>
            <!-- keep 60 days worth of history -->
            <MaxHistory>60</MaxHistory>
        </rollingPolicy>
        <layout class="ch.qos.logback.classic.PatternLayout">
            <Pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} %X{REQUEST_ID} - %msg%n</Pattern>
        </layout>
    </appender>

package ch.qos.logback.classic.util;

public final class LogbackMDCAdapter implements MDCAdapter {
final InheritableThreadLocal<Map<String, String>> copyOnInheritThreadLocal = new InheritableThreadLocal<Map<String, String>>();

//往copyOnInheritThreadLocal里的map放值
  public void put(String key, String val) throws IllegalArgumentException {
//key不能为空
    if (key == null) {
      throw new IllegalArgumentException("key cannot be null");
    }
//通过copyOnInheritThreadLocal 得到map对象
    Map<String, String> oldMap = copyOnInheritThreadLocal.get();
//将标识为设置为写
    Integer lastOp = getAndSetLastOperation(WRITE_OPERATION);
//第一次读或者在写之前有读操作，都会新创建一个新的map对象，重复创建是为了避免当前线程创建的子线程的值受当前线程的影响。
    if (wasLastOpReadOrNull(lastOp) || oldMap == null) {
      Map<String, String> newMap = duplicateAndInsertNewMap(oldMap);
      newMap.put(key, val);
    } else {
      oldMap.put(key, val);
    }
  }

//会新创建一个新的map对象
  private Map<String, String> duplicateAndInsertNewMap(Map<String, String> oldMap) {
    Map<String, String> newMap = Collections.synchronizedMap(new HashMap<String, String>());
    if (oldMap != null) {
        // we don't want the parent thread modifying oldMap while we are
        // iterating over it
        synchronized (oldMap) {
          newMap.putAll(oldMap);
        }
    }
//新建的值会设置到copyOnInheritThreadLocal里
    copyOnInheritThreadLocal.set(newMap);
    return newMap;
  }

}