用Log4J 1.2.x的框架时，我们需要三个jar包：log4j-1.2.3.jar slf4j-api-1.6.2jar slf4j-log4j12-1.6.2jar 从名字上可以看出第三个是主要的jar包，提供了前两者的增强功能。
下面我们以一个例子来说明日志过滤器的配置方法：
首先我们创建一个log4j的配置文件并设置日志输出级别为debug：
log4j.appender.MINA=org.apache.log4j.ConsoleAppenderlog4j.appender.MINA.layout=org.apache.log4j.PatternLayout
log4j.appender.MINA.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %m%n
#to console#
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %m%n
#to file#
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=./log/minademos.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %l %m%n
#error/warn/info/debug#
log4j.rootLogger=debug, stdout,MINA,file
接下来我们写一个服务器端的代码，在8080端口启动一个服务：
package com.yushh.test.logging;import java.io.IOException;
import java.net.InetSocketAddress;
import org.apache.mina.core.filterchain.DefaultIoFilterChainBuilder;
import org.apache.mina.core.service.IoAcceptor;
import org.apache.mina.filter.logging.LogLevel;
import org.apache.mina.filter.logging.LoggingFilter;
import org.apache.mina.transport.socket.nio.NioSocketAcceptor;
public class EchoServer {
private static final int PORT = 8080;
public static void main(String[] args) throws IOException {
IoAcceptor acceptor = new NioSocketAcceptor();
DefaultIoFilterChainBuilder chain = acceptor.getFilterChain();
LoggingFilter loggingFilter = new LoggingFilter();
chain.addLast("logging", loggingFilter);
acceptor.setDefaultLocalAddress(new InetSocketAddress(PORT));
acceptor.setHandler(new EchoProtocolHandler());
acceptor.bind();
System.out.println("Listening on port " + PORT);
}
}
注意此处没有具体配置loggingFilter，下面我们用dos telnet本机的8080端口得到如下的日志信息：
Listening on port 80802012-03-15 14:34:56 CREATED
2012-03-15 14:34:56 CREATED
2012-03-15 14:34:56 OPENED
2012-03-15 14:34:56 OPENED
2012-03-15 14:34:58 RECEIVED: HeapBuffer[pos=0 lim=1 cap=2048: 61]
2012-03-15 14:34:58 RECEIVED: HeapBuffer[pos=0 lim=1 cap=2048: 61]
2012-03-15 14:35:00 RECEIVED: HeapBuffer[pos=0 lim=1 cap=2048: 62]
2012-03-15 14:35:00 RECEIVED: HeapBuffer[pos=0 lim=1 cap=2048: 62]
2012-03-15 14:35:01 RECEIVED: HeapBuffer[pos=0 lim=1 cap=1024: 63]
2012-03-15 14:35:01 RECEIVED: HeapBuffer[pos=0 lim=1 cap=1024: 63]
2012-03-15 14:35:02 RECEIVED: HeapBuffer[pos=0 lim=1 cap=1024: 41]
2012-03-15 14:35:02 RECEIVED: HeapBuffer[pos=0 lim=1 cap=1024: 41]
2012-03-15 14:35:05 CLOSED
2012-03-15 14:35:05 CLOSED
可见session的几种生命周期都被答应出来，从输出的RECEIVED信息中可以看见我在客户端输入的字符为‘abcA’，呵呵这个以后再讨论。
下面我们修改一下服务器代码：
package com.yushh.test.logging;import java.io.IOException;
import java.net.InetSocketAddress;
import org.apache.mina.core.filterchain.DefaultIoFilterChainBuilder;
import org.apache.mina.core.service.IoAcceptor;
import org.apache.mina.filter.logging.LogLevel;
import org.apache.mina.filter.logging.LoggingFilter;
import org.apache.mina.transport.socket.nio.NioSocketAcceptor;
public class EchoServer {
private static final int PORT = 8080;
public static void main(String[] args) throws IOException {
IoAcceptor acceptor = new NioSocketAcceptor();
DefaultIoFilterChainBuilder chain = acceptor.getFilterChain();
LoggingFilter loggingFilter = new LoggingFilter();
loggingFilter.setSessionClosedLogLevel(LogLevel.NONE);
loggingFilter.setSessionCreatedLogLevel(LogLevel.DEBUG);
loggingFilter.setSessionOpenedLogLevel(LogLevel.INFO);
chain.addLast("logging", loggingFilter);
acceptor.setDefaultLocalAddress(new InetSocketAddress(PORT));
acceptor.setHandler(new EchoProtocolHandler());
acceptor.bind();
System.out.println("Listening on port " + PORT);
}
}
我们在LoggingFilter 增加了日志输出级别，设置当session关闭时不打印任何日志，当session建立时日志为debug级别，当session打开的时候日志为info级别，同样的客户端测试结果如下：
Listening on port 80802012-03-15 14:38:03 CREATED
2012-03-15 14:38:03 CREATED
2012-03-15 14:38:03 OPENED
2012-03-15 14:38:03 OPENED
2012-03-15 14:38:05 RECEIVED: HeapBuffer[pos=0 lim=1 cap=2048: 61]
2012-03-15 14:38:05 RECEIVED: HeapBuffer[pos=0 lim=1 cap=2048: 61]
2012-03-15 14:38:05 RECEIVED: HeapBuffer[pos=0 lim=1 cap=2048: 62]
2012-03-15 14:38:05 RECEIVED: HeapBuffer[pos=0 lim=1 cap=2048: 62]
2012-03-15 14:38:08 RECEIVED: HeapBuffer[pos=0 lim=1 cap=1024: 63]
2012-03-15 14:38:08 RECEIVED: HeapBuffer[pos=0 lim=1 cap=1024: 63]
2012-03-15 14:38:09 RECEIVED: HeapBuffer[pos=0 lim=1 cap=1024: 41]
2012-03-15 14:38:09 RECEIVED: HeapBuffer[pos=0 lim=1 cap=1024: 41]
可见mina优先使用代码中的 日志输出级别。