log4j2 RollingRandomAccessFile配置过程

<? xml version = "1.0" encoding = "UTF-8" ?>

< Configuration status = "INFO" monitorInterval = "120" >

     < properties > 

         < property name = "MSG_LOG_HOME" >/data/gpslog</ property >

     </ properties >

     < Appenders >

         < Console name = "Console" target = "SYSTEM_OUT" >

             < PatternLayout pattern = "%d [%t] %-5p [%c] - %m%n" />

         </ Console >

         < RollingRandomAccessFile name = "msgAppender" immediateFlush = "true"

             fileName = "${MSG_LOG_HOME}/msg.log"

             filePattern = "${MSG_LOG_HOME}/backup/msg.%d{yyyyMMddHH}.zip" >

             < Filters >

                 < ThresholdFilter level = "INFO" onMatch = "ACCEPT" onMismatch = "DENY" />

             </ Filters >

             < PatternLayout pattern = "%m%n" />

             < Policies >

                 < TimeBasedTriggeringPolicy interval = "1" modulate = "true" />

             </ Policies > 

             < DefaultRolloverStrategy max = "24" >

                 < Delete basePath = "${MSG_LOG_HOME}" maxDepth = "2" >

                   < IfFileName glob = "*/msg.*.zip" />

                   < IfLastModified age = "24H" />

                 </ Delete >

             </ DefaultRolloverStrategy >

         </ RollingRandomAccessFile >

     </ Appenders >

     < Loggers >

         < AsyncLogger name = "com.roadway.DebugUtils" additivity = "FALSE" level = "INFO" >

             < appender-ref ref = "msgAppender" />

         </ AsyncLogger >

     </ Loggers >

</ Configuration >

< DefaultRolloverStrategy max = "24" >

     < Delete basePath = "${MSG_LOG_HOME}" maxDepth = "2" >

         < IfFileName glob = "*/msg.*.zip" />

         < IfLastModified age = "24H" />

     </ Delete >

</ DefaultRolloverStrategy >

< RollingRandomAccessFile name = "msgAppender"

    immediateFlush = "false"

    bufferSize = "512"

    fileName = "${MSG_LOG_HOME}/msg.log"

    filePattern = "${MSG_LOG_HOME}/backup/msg.%d{yyyyMMddHH}.zip" >

    ......

......

< AsyncLogger name = "com.roadway.DebugUtils" additivity = "FALSE" level = "INFO" >

     < appender-ref ref = "msgAppender" />

</ AsyncLogger >

......

public class DownLoadThread extends Thread {​

     private long start;

     private File src;

     private long total;

     private File desc;

​

     /**

      *

      * @param start

      *            开始下载的位置

      * @param src

      *            要下载的文件

      * @param desc

      *            要下载的目的地

      * @param total

      *            要下载的总量

      */

     public DownLoadThread( long start, File src, File desc, long total) {

         this .start = start;

         this .src = src;

         this .desc = desc;

         this .total = total;

     }

​

     @Override

     public void run() {

         try {

             // 创建输入流关联源,因为要指定位置读和写,所以我们需要用随机访问流

             RandomAccessFile src = new RandomAccessFile( this .src, "rw" );

             RandomAccessFile desc = new RandomAccessFile( this .desc, "rw" );

​

             // 源和目的都要从start开始

             src.seek(start);

             desc.seek(start);

             // 开始读写

             byte [] arr = new byte [ 1024 ];

             int len;

             long count = 0 ;

             while ((len = src.read(arr)) != - 1 ) {

                 //分三种情况

                 if (len + count > total) {

                      //1.当读取的时候操作自己该线程的下载总量的时候,需要改变len

                     len = ( int ) (total - count);

                     desc.write(arr, 0 , len);

                     //证明该线程下载任务已经完毕,结束读写操作

                     break ;

                 } else if (len + count < total) {

                     //2.证明还没有到下载总量,直接将内容写入

                     desc.write(arr, 0 , len);

                     //并且使计数器任务累加

                     count += arr.length;

                 } else {

                     //3.证明改好到下载总量

                     desc.write(arr, 0 , len);

                     //结束读写

                     break ;

                 }

             }

             src.close();

             desc.close();

​

         } catch (Exception e) {

             e.printStackTrace();

         }

     }

}

public class TestRandomAccess {​

     public static void main(String[] args) {

         //关联源

         File src = new File( "a.txt" );

         //关联目的

         File desc = new File( "b.txt" );

​

         //获取源的总大小

         long length = src.length();

         // 开两条线程,并分配下载任务

         new DownLoadThread( 0 , src, desc, length / 2 ).start();

         new DownLoadThread(length / 2 , src, desc, length - (length / 2 )).start();

     }​

}