mina 使用手記3

在上一篇中，通過一個簡單的例子，得以管中窺豹，瞭解了Mina的基本編寫方法。在MinaTimeServer演示程序中，我們添加了兩個過濾 器，一個是日誌過濾器LoggingFilter，一個是文本編解碼過濾器。前者實現日誌信息的自動處理，後者實現對按行讀寫的文本數據的編碼和解碼。

其中LoggingFilter默認的是slf4j，它是一個日誌Facade，實際並不實現真正的日誌處理功能，它在程序運行時自動判斷 classpath中加載的日誌組件，比如：log4j/Logback/JUL等，確定之後調用真正的日誌組件實現真正的日誌處理操作。這一點對於組件 式的程序，很明顯是非常靈活的，因爲你並不知道用戶的實際環境中使用的是log4j還是JUL，或者是Logback等，但是爲了實現自動識 別，slf4j默認了log配置文件的加載位置，讓我覺得十分不便。

我自己的所有系統中，都使用是log4j（他的替代產品Logback已經出來了，據說性能更強），我一般喜歡把所有配置文件包括 log4j.properties都放在conf目錄下，以便管理。因此，對於slf4j中需要把log4j.properties放在src文件夾下非 常不習慣，對於以後管理也容易引起混亂。所以，我希望能直接實現自己的log4j過濾器，按以前的方式使用。我們觀察一下LoggingFilter過濾 器的源代碼，如下所示：

public
 
class
 LoggingFilter 
extends
 IoFilterAdapter{...}

public class LoggingFilter extends IoFilterAdapter{...}

LoggingFilter繼承自IoFilterAdapter，它是java模型中的適配器模式，是對接口IoFilter的包裝。我們可以模仿LoggingFilter，實現自己的Log4jFilter類：

import
 org.apache.log4j.Level;
import
 org.apache.log4j.Logger;
import
 org.apache.mina.core.filterchain.IoFilterAdapter;
import
 org.apache.mina.core.session.IdleStatus;
import
 org.apache.mina.core.session.IoSession;
import
 org.apache.mina.core.write.WriteRequest;
import
 org.apache.mina.filter.logging.LogLevel;
import
 org.slf4j.helpers.MessageFormatter;
public
 
class
 Log4jFilter 
extends
 IoFilterAdapter {
    /** The logger name */
    private
 
final
 String name;

    /** The logger */
    private
 
final
 Logger logger;

    /** The log level for the exceptionCaught event. Default to WARN. */
    private
 LogLevel exceptionCaughtLevel = LogLevel.WARN;

    /** The log level for the messageSent event. Default to INFO. */
    private
 LogLevel messageSentLevel = LogLevel.INFO;

    /** The log level for the messageReceived event. Default to INFO. */
    private
 LogLevel messageReceivedLevel = LogLevel.INFO;

    /** The log level for the sessionCreated event. Default to INFO. */
    private
 LogLevel sessionCreatedLevel = LogLevel.INFO;

    /** The log level for the sessionOpened event. Default to INFO. */
    private
 LogLevel sessionOpenedLevel = LogLevel.INFO;

    /** The log level for the sessionIdle event. Default to INFO. */
    private
 LogLevel sessionIdleLevel = LogLevel.INFO;

    /** The log level for the sessionClosed event. Default to INFO. */
    private
 LogLevel sessionClosedLevel = LogLevel.INFO;

    /**
     * Default Constructor.
     */
    public
 Log4jFilter(Logger logger) {
        this
.logger=logger;
        this
.name=logger.getName();
    }



    /**
     * @return The logger's name
     */
    public
 String getName() {
        return
 name;
    }

    /**
     * Log if the logger and the current event log level are compatible. We log
     * a message and an exception.
     *
     * @param eventLevel the event log level as requested by the user
     * @param message the message to log
     * @param cause the exception cause to log
     */
    private
 
void
 log(LogLevel eventLevel, String message, Throwable cause) {
        if
 (eventLevel == LogLevel.TRACE) {
            logger.trace(message, cause);
        } else
 
if
 (eventLevel.getLevel() > LogLevel.INFO.getLevel()) {
            logger.info(message, cause);
        } else
 
if
 (eventLevel.getLevel() > LogLevel.WARN.getLevel()) {
            logger.warn(message, cause);
        } else
 
if
 (eventLevel.getLevel() > LogLevel.ERROR.getLevel()) {
            logger.error(message, cause);
        }
    }
    /**
     * Log if the logger and the current event log level are compatible. We log
     * a formated message and its parameters.
     *
     * @param eventLevel the event log level as requested by the user
     * @param message the formated message to log
     * @param param the parameter injected into the message
     */
    private
 
void
 log(LogLevel eventLevel, String message, Object param) {
        String msgStr = MessageFormatter.format(message, param);
        if
 (eventLevel == LogLevel.TRACE) {
            logger.log(name, Level.TRACE, msgStr, null
);

        } else
 
if
 (eventLevel.getLevel() > LogLevel.INFO.getLevel()) {
            logger.log(name, Level.INFO, msgStr, null
);
        } else
 
if
 (eventLevel.getLevel() > LogLevel.WARN.getLevel()) {
            logger.log(name, Level.WARN, msgStr, null
);
        } else
 
if
 (eventLevel.getLevel() > LogLevel.ERROR.getLevel()) {
            logger.log(name, Level.ERROR, msgStr, null
);
        }
    }
    /**
     * Log if the logger and the current event log level are compatible. We log
     * a simple message.
     *
     * @param eventLevel the event log level as requested by the user
     * @param message the message to log
     */
    private
 
void
 log(LogLevel eventLevel, String message) {
        if
 (eventLevel == LogLevel.TRACE) {
            logger.trace(message);
        } else
 
if
 (eventLevel.getLevel() > LogLevel.INFO.getLevel()) {
            logger.info(message);
        } else
 
if
 (eventLevel.getLevel() > LogLevel.WARN.getLevel()) {
            logger.warn(message);
        } else
 
if
 (eventLevel.getLevel() > LogLevel.ERROR.getLevel()) {
            logger.error(message);
        }
    }
    @Override
    public
 
void
 exceptionCaught(NextFilter nextFilter, IoSession session,
            Throwable cause) throws
 Exception {
        log(exceptionCaughtLevel, "EXCEPTION :"
, cause);
        nextFilter.exceptionCaught(session, cause);
    }
    @Override
    public
 
void
 messageReceived(NextFilter nextFilter, IoSession session,
            Object message) throws
 Exception {
        log(messageReceivedLevel, "RECEIVED: {}"
, message );
        nextFilter.messageReceived(session, message);
    }
    @Override
    public
 
void
 messageSent(NextFilter nextFilter, IoSession session,
            WriteRequest writeRequest) throws
 Exception {
        log(messageSentLevel, "SENT: {}"
, writeRequest.getMessage() );
        nextFilter.messageSent(session, writeRequest);
    }
    @Override
    public
 
void
 sessionCreated(NextFilter nextFilter, IoSession session)
            throws
 Exception {
        log(sessionCreatedLevel, "CREATED"
);
        nextFilter.sessionCreated(session);
    }
    @Override
    public
 
void
 sessionOpened(NextFilter nextFilter, IoSession session)
    throws
 Exception {
        log(sessionOpenedLevel, "OPENED"
);
        nextFilter.sessionOpened(session);
    }
    @Override
    public
 
void
 sessionIdle(NextFilter nextFilter, IoSession session,
            IdleStatus status) throws
 Exception {
        log(sessionIdleLevel, "IDLE"
);
        nextFilter.sessionIdle(session, status);
    }
    @Override
    public
 
void
 sessionClosed(NextFilter nextFilter, IoSession session) 
throws
 Exception {
        log(sessionClosedLevel, "CLOSED"
);
        nextFilter.sessionClosed(session);
    }

    /**
     * Set the LogLevel for the ExceptionCaught event.
     *
     * @param level The LogLevel to set
     */
    public
 
void
 setExceptionCaughtLoglevel(LogLevel level) {
        exceptionCaughtLevel = level;
    }

    /**
     * Get the LogLevel for the ExceptionCaught event.
     *
     * @return The LogLevel for the ExceptionCaught eventType
     */
    public
 LogLevel getExceptionCaughtLoglevel() {
        return
 exceptionCaughtLevel;
    }

    /**
     * Set the LogLevel for the MessageReceived event.
     *
     * @param level The LogLevel to set
     */
    public
 
void
 setMessageReceivedLoglevel(LogLevel level) {
        messageReceivedLevel = level;
    }

    /**
     * Get the LogLevel for the MessageReceived event.
     *
     * @return The LogLevel for the MessageReceived eventType
     */
    public
 LogLevel getMessageReceivedLoglevel() {
        return
 messageReceivedLevel;
    }

    /**
     * Set the LogLevel for the MessageSent event.
     *
     * @param level The LogLevel to set
     */
    public
 
void
 setMessageSentLoglevel(LogLevel level) {
        messageSentLevel = level;
    }

    /**
     * Get the LogLevel for the MessageSent event.
     *
     * @return The LogLevel for the MessageSent eventType
     */
    public
 LogLevel getMessageSentLoglevel() {
        return
 messageSentLevel;
    }

    /**
     * Set the LogLevel for the SessionCreated event.
     *
     * @param level The LogLevel to set
     */
    public
 
void
 setSessionCreatedLoglevel(LogLevel level) {
        sessionCreatedLevel = level;
    }

    /**
     * Get the LogLevel for the SessionCreated event.
     *
     * @return The LogLevel for the SessionCreated eventType
     */
    public
 LogLevel getSessionCreatedLoglevel() {
        return
 sessionCreatedLevel;
    }

    /**
     * Set the LogLevel for the SessionOpened event.
     *
     * @param level The LogLevel to set
     */
    public
 
void
 setSessionOpenedLoglevel(LogLevel level) {
        sessionOpenedLevel = level;
    }

    /**
     * Get the LogLevel for the SessionOpened event.
     *
     * @return The LogLevel for the SessionOpened eventType
     */
    public
 LogLevel getSessionOpenedLoglevel() {
        return
 sessionOpenedLevel;
    }

    /**
     * Set the LogLevel for the SessionIdle event.
     *
     * @param level The LogLevel to set
     */
    public
 
void
 setSessionIdleLoglevel(LogLevel level) {
        sessionIdleLevel = level;
    }

    /**
     * Get the LogLevel for the SessionIdle event.
     *
     * @return The LogLevel for the SessionIdle eventType
     */
    public
 LogLevel getSessionIdleLoglevel() {
        return
 sessionIdleLevel;
    }

    /**
     * Set the LogLevel for the SessionClosed event.
     *
     * @param level The LogLevel to set
     */
    public
 
void
 setSessionClosedLoglevel(LogLevel level) {
        sessionClosedLevel = level;
    }
    /**
     * Get the LogLevel for the SessionClosed event.
     *
     * @return The LogLevel for the SessionClosed eventType
     */
    public
 LogLevel getSessionClosedLoglevel() {
        return
 sessionClosedLevel;
    }
}

import org.apache.log4j.Level; import org.apache.log4j.Logger; import org.apache.mina.core.filterchain.IoFilterAdapter; import org.apache.mina.core.session.IdleStatus; import org.apache.mina.core.session.IoSession; import org.apache.mina.core.write.WriteRequest; import org.apache.mina.filter.logging.LogLevel; import org.slf4j.helpers.MessageFormatter; public class Log4jFilter extends IoFilterAdapter { /** The logger name */ private final String name; /** The logger */ private final Logger logger; /** The log level for the exceptionCaught event. Default to WARN. */ private LogLevel exceptionCaughtLevel = LogLevel.WARN; /** The log level for the messageSent event. Default to INFO. */ private LogLevel messageSentLevel = LogLevel.INFO; /** The log level for the messageReceived event. Default to INFO. */ private LogLevel messageReceivedLevel = LogLevel.INFO; /** The log level for the sessionCreated event. Default to INFO. */ private LogLevel sessionCreatedLevel = LogLevel.INFO; /** The log level for the sessionOpened event. Default to INFO. */ private LogLevel sessionOpenedLevel = LogLevel.INFO; /** The log level for the sessionIdle event. Default to INFO. */ private LogLevel sessionIdleLevel = LogLevel.INFO; /** The log level for the sessionClosed event. Default to INFO. */ private LogLevel sessionClosedLevel = LogLevel.INFO; /** * Default Constructor. */ public Log4jFilter(Logger logger) { this.logger=logger; this.name=logger.getName(); } /** * @return The logger's name */ public String getName() { return name; } /** * Log if the logger and the current event log level are compatible. We log * a message and an exception. * * @param eventLevel the event log level as requested by the user * @param message the message to log * @param cause the exception cause to log */ private void log(LogLevel eventLevel, String message, Throwable cause) { if (eventLevel == LogLevel.TRACE) { logger.trace(message, cause); } else if (eventLevel.getLevel() > LogLevel.INFO.getLevel()) { logger.info(message, cause); } else if (eventLevel.getLevel() > LogLevel.WARN.getLevel()) { logger.warn(message, cause); } else if (eventLevel.getLevel() > LogLevel.ERROR.getLevel()) { logger.error(message, cause); } } /** * Log if the logger and the current event log level are compatible. We log * a formated message and its parameters. * * @param eventLevel the event log level as requested by the user * @param message the formated message to log * @param param the parameter injected into the message */ private void log(LogLevel eventLevel, String message, Object param) { String msgStr = MessageFormatter.format(message, param); if (eventLevel == LogLevel.TRACE) { logger.log(name, Level.TRACE, msgStr, null); } else if (eventLevel.getLevel() > LogLevel.INFO.getLevel()) { logger.log(name, Level.INFO, msgStr, null); } else if (eventLevel.getLevel() > LogLevel.WARN.getLevel()) { logger.log(name, Level.WARN, msgStr, null); } else if (eventLevel.getLevel() > LogLevel.ERROR.getLevel()) { logger.log(name, Level.ERROR, msgStr, null); } } /** * Log if the logger and the current event log level are compatible. We log * a simple message. * * @param eventLevel the event log level as requested by the user * @param message the message to log */ private void log(LogLevel eventLevel, String message) { if (eventLevel == LogLevel.TRACE) { logger.trace(message); } else if (eventLevel.getLevel() > LogLevel.INFO.getLevel()) { logger.info(message); } else if (eventLevel.getLevel() > LogLevel.WARN.getLevel()) { logger.warn(message); } else if (eventLevel.getLevel() > LogLevel.ERROR.getLevel()) { logger.error(message); } } @Override public void exceptionCaught(NextFilter nextFilter, IoSession session, Throwable cause) throws Exception { log(exceptionCaughtLevel, "EXCEPTION :", cause); nextFilter.exceptionCaught(session, cause); } @Override public void messageReceived(NextFilter nextFilter, IoSession session, Object message) throws Exception { log(messageReceivedLevel, "RECEIVED: {}", message ); nextFilter.messageReceived(session, message); } @Override public void messageSent(NextFilter nextFilter, IoSession session, WriteRequest writeRequest) throws Exception { log(messageSentLevel, "SENT: {}", writeRequest.getMessage() ); nextFilter.messageSent(session, writeRequest); } @Override public void sessionCreated(NextFilter nextFilter, IoSession session) throws Exception { log(sessionCreatedLevel, "CREATED"); nextFilter.sessionCreated(session); } @Override public void sessionOpened(NextFilter nextFilter, IoSession session) throws Exception { log(sessionOpenedLevel, "OPENED"); nextFilter.sessionOpened(session); } @Override public void sessionIdle(NextFilter nextFilter, IoSession session, IdleStatus status) throws Exception { log(sessionIdleLevel, "IDLE"); nextFilter.sessionIdle(session, status); } @Override public void sessionClosed(NextFilter nextFilter, IoSession session) throws Exception { log(sessionClosedLevel, "CLOSED"); nextFilter.sessionClosed(session); } /** * Set the LogLevel for the ExceptionCaught event. * * @param level The LogLevel to set */ public void setExceptionCaughtLoglevel(LogLevel level) { exceptionCaughtLevel = level; } /** * Get the LogLevel for the ExceptionCaught event. * * @return The LogLevel for the ExceptionCaught eventType */ public LogLevel getExceptionCaughtLoglevel() { return exceptionCaughtLevel; } /** * Set the LogLevel for the MessageReceived event. * * @param level The LogLevel to set */ public void setMessageReceivedLoglevel(LogLevel level) { messageReceivedLevel = level; } /** * Get the LogLevel for the MessageReceived event. * * @return The LogLevel for the MessageReceived eventType */ public LogLevel getMessageReceivedLoglevel() { return messageReceivedLevel; } /** * Set the LogLevel for the MessageSent event. * * @param level The LogLevel to set */ public void setMessageSentLoglevel(LogLevel level) { messageSentLevel = level; } /** * Get the LogLevel for the MessageSent event. * * @return The LogLevel for the MessageSent eventType */ public LogLevel getMessageSentLoglevel() { return messageSentLevel; } /** * Set the LogLevel for the SessionCreated event. * * @param level The LogLevel to set */ public void setSessionCreatedLoglevel(LogLevel level) { sessionCreatedLevel = level; } /** * Get the LogLevel for the SessionCreated event. * * @return The LogLevel for the SessionCreated eventType */ public LogLevel getSessionCreatedLoglevel() { return sessionCreatedLevel; } /** * Set the LogLevel for the SessionOpened event. * * @param level The LogLevel to set */ public void setSessionOpenedLoglevel(LogLevel level) { sessionOpenedLevel = level; } /** * Get the LogLevel for the SessionOpened event. * * @return The LogLevel for the SessionOpened eventType */ public LogLevel getSessionOpenedLoglevel() { return sessionOpenedLevel; } /** * Set the LogLevel for the SessionIdle event. * * @param level The LogLevel to set */ public void setSessionIdleLoglevel(LogLevel level) { sessionIdleLevel = level; } /** * Get the LogLevel for the SessionIdle event. * * @return The LogLevel for the SessionIdle eventType */ public LogLevel getSessionIdleLoglevel() { return sessionIdleLevel; } /** * Set the LogLevel for the SessionClosed event. * * @param level The LogLevel to set */ public void setSessionClosedLoglevel(LogLevel level) { sessionClosedLevel = level; } /** * Get the LogLevel for the SessionClosed event. * * @return The LogLevel for the SessionClosed eventType */ public LogLevel getSessionClosedLoglevel() { return sessionClosedLevel; } }

其實代碼很類似，在MinaTimeServer中使用Log4jFilter使使看：

package
 com.gftech.mytool.mina;
import
 java.io.IOException;
import
 java.net.InetSocketAddress;
import
 java.nio.charset.Charset;
import
 java.util.Date;
import
 org.apache.log4j.Logger;
import
 org.apache.log4j.PropertyConfigurator;
import
 org.apache.mina.core.service.IoAcceptor;
import
 org.apache.mina.core.service.IoHandlerAdapter;
import
 org.apache.mina.core.session.IdleStatus;
import
 org.apache.mina.core.session.IoSession;
import
 org.apache.mina.filter.codec.ProtocolCodecFilter;
import
 org.apache.mina.filter.codec.textline.TextLineCodecFactory;
import
 org.apache.mina.transport.socket.nio.NioSocketAcceptor;
public
 
class
 MinaTimeServer {
    private
 
static
 
final
 
int
 PORT = 
2500
;
    // static Logger logger = LoggerFactory.getLogger(MinaTimeServer.class);
    static
 Logger logger = Logger.getLogger(MinaTimeServer.
class
);
    public
 
static
 
void
 main(String[] args) 
throws
 IOException {
        PropertyConfigurator.configure("conf//log4j.properties"
);
        IoAcceptor acceptor = new
 NioSocketAcceptor();
        // LoggingFilter lf = new LoggingFilter("testLog");
        Log4jFilter lf = new
 Log4jFilter(logger);
        acceptor.getFilterChain().addLast("logger"
, lf);
        acceptor.getFilterChain().addLast("codec"
, 
new
 ProtocolCodecFilter(
new
 TextLineCodecFactory(Charset.forName(
"GBK"
))));
        acceptor.setHandler(new
 TimeServerHandler());
        acceptor.getSessionConfig().setReadBufferSize(10
);
        acceptor.getSessionConfig().setIdleTime(IdleStatus.BOTH_IDLE, 10
);
        acceptor.bind(new
 InetSocketAddress(PORT));
        System.out.println("start server ..."
);
    }
}
class
 TimeServerHandler 
extends
 IoHandlerAdapter {
    // static Logger logger = LoggerFactory.getLogger(TimeServerHandler.class);
    static
 Logger logger = Logger.getLogger(TimeServerHandler.
class
);
    @Override
    public
 
void
 exceptionCaught(IoSession session, Throwable cause) 
throws
 Exception {
        cause.printStackTrace();
    }
    @Override
    public
 
void
 messageReceived(IoSession session, Object message) 
throws
 Exception {
        String str = message.toString();
        if
 (str.trim().equalsIgnoreCase(
"quit"
)) {
            session.close(true
);
            return
;
        }
        logger.debug("Rec:"
 + str);
        Date date = new
 Date();
        session.write(date.toString());
        logger.debug("Message written..."
);
    }
    @Override
    public
 
void
 sessionIdle(IoSession session, IdleStatus status) 
throws
 Exception {
        logger.debug("IDLE "
 + session.getIdleCount(status));
    }
}

package com.gftech.mytool.mina; import java.io.IOException; import java.net.InetSocketAddress; import java.nio.charset.Charset; import java.util.Date; import org.apache.log4j.Logger; import org.apache.log4j.PropertyConfigurator; import org.apache.mina.core.service.IoAcceptor; import org.apache.mina.core.service.IoHandlerAdapter; import org.apache.mina.core.session.IdleStatus; import org.apache.mina.core.session.IoSession; import org.apache.mina.filter.codec.ProtocolCodecFilter; import org.apache.mina.filter.codec.textline.TextLineCodecFactory; import org.apache.mina.transport.socket.nio.NioSocketAcceptor; public class MinaTimeServer { private static final int PORT = 2500; // static Logger logger = LoggerFactory.getLogger(MinaTimeServer.class); static Logger logger = Logger.getLogger(MinaTimeServer.class); public static void main(String[] args) throws IOException { PropertyConfigurator.configure("conf//log4j.properties"); IoAcceptor acceptor = new NioSocketAcceptor(); // LoggingFilter lf = new LoggingFilter("testLog"); Log4jFilter lf = new Log4jFilter(logger); acceptor.getFilterChain().addLast("logger", lf); acceptor.getFilterChain().addLast("codec", new ProtocolCodecFilter(new TextLineCodecFactory(Charset.forName("GBK")))); acceptor.setHandler(new TimeServerHandler()); acceptor.getSessionConfig().setReadBufferSize(10); acceptor.getSessionConfig().setIdleTime(IdleStatus.BOTH_IDLE, 10); acceptor.bind(new InetSocketAddress(PORT)); System.out.println("start server ..."); } } class TimeServerHandler extends IoHandlerAdapter { // static Logger logger = LoggerFactory.getLogger(TimeServerHandler.class); static Logger logger = Logger.getLogger(TimeServerHandler.class); @Override public void exceptionCaught(IoSession session, Throwable cause) throws Exception { cause.printStackTrace(); } @Override public void messageReceived(IoSession session, Object message) throws Exception { String str = message.toString(); if (str.trim().equalsIgnoreCase("quit")) { session.close(true); return; } logger.debug("Rec:" + str); Date date = new Date(); session.write(date.toString()); logger.debug("Message written..."); } @Override public void sessionIdle(IoSession session, IdleStatus status) throws Exception { logger.debug("IDLE " + session.getIdleCount(status)); } }

把配置文件按照自己的習慣放到conf目錄下，就可以正常使用了。

需要注意的是，增加了自己的Log4jFilter之後，只能在您自己的代碼中實現logger.debug()之類的調用時產生的日誌記錄纔是正 常的，即按配置文件中的要求老老實實進行日誌記錄。對於Mina代碼中用到的logger調用，因爲還是用的默認的slf4j，找不到src目錄下的 log4j.properties，所以產生的日誌將無法正確顯示和記錄。除非您自己的將mina源代碼中的logger全部改成log4j的 logger，這是個小小的遺憾，魚和熊掌不能兼得呀。

下一篇中，我們將介紹，如何編寫自己的編解碼過濾器。