serverwithlog4j.java

log4j的基本功能的实现包括属性文件的配置

package log4j;
import java.util.* ;
import java.io.* ;
import java.net.* ;

// add for log4j: import some package
import org.apache.log4j.PropertyConfigurator ;
import org.apache.log4j.Logger ;
import org.apache.log4j.Level ;

/**
*
* <p> Server With Log4j </p>
* <p> Description: a sample with log4j</p>
* @version 1.0
*/
public class ServerWithLog4j {

final static int SERVER_PORT = 8001 ; // this server's port

/*
add for log4j: class Logger is the central class in the log4j package.
we can do most logging operations by Logger except configuration.
getLogger(...): retrieve a logger by name, if not then create for it.
*/
static Logger logger = Logger.getLogger 
( ServerWithLog4j.class.getName () ) ;

/**
   *
   * @param args
   */
public static void main ( String args[]) {
      String clientRequest = null ;
      BufferedReader reader = null ;
      PrintWriter writer = null ;
      ServerSocket server = null ;
      Socket socket = null ;

      InputStream in = null ;
      OutputStream out = null ;

      /*
      add for log4j: class BasicConfigurator can quickly configure the package.
      print the information to console.
      */
     //PropertyConfigurator.configure ( "D:\\Documents and Settings\\Administrator\\workspace\\Testlog4j\\src\\log4j\\ServerWithLog4j.properties" ) ;
     //PropertyConfigurator.configure ( "D:/Documents and Settings/Administrator/workspace/Testlog4j/bin/log4j/ServerWithLog4j.properties" ) ;
    // URL str=ServerWithLog4j.class.getResource("");
    // System.out.println("aaaa:"+str+"ServerWithLog4j.properties" );
     PropertyConfigurator.configure ( "Log4jProperty/ServerWithLog4j.properties" ) ;   
      // add for log4j: set the level
//        logger.setLevel ( ( Level ) Level.DEBUG ) ;

      try{
          server = new ServerSocket ( SERVER_PORT ) ;

          // add for log4j: log a message with the info level
          logger.info ( "ServerSocket before accept: " + server ) ;

          // add for log4j: log a message with the info level
          logger.info ( "Java server with log4j, on-line!" ) ;

          // wait for client's connection
          socket = server.accept() ;

          // add for log4j: log a message with the info level
          logger.info ( "ServerSocket after accept: " + server ) ;

          in = socket.getInputStream() ;
          out = socket.getOutputStream() ;

      } catch ( IOException e ) {

          // add for log4j: log a message with the error level
          logger.error ( "Server constructor IOException: " + e ) ;
          System.exit ( 0 ) ;
      }
      reader = new BufferedReader ( new InputStreamReader ( in ) ) ;
      writer = new PrintWriter ( new OutputStreamWriter ( out ), true ) ;

      // send welcome string to client
      writer.println ( "Java server with log4j, " + new Date () ) ;

      while ( true ) {
          try {
              // read from client
              clientRequest = reader.readLine () ;

              // add for log4j: log a message with the debug level
              logger.debug ( "Client says: " + clientRequest ) ;

              if ( clientRequest.startsWith ( "HELP" ) ) {

                  // add for log4j: log a message with the debug level
                  logger.debug ( "OK!" ) ;

                  writer.println ( "Vocabulary: HELP QUIT" ) ;
              }
              else {
                  if ( clientRequest.startsWith ( "QUIT" ) ) {

                      // add for log4j: log a message with the debug level
                      logger.debug ( "OK!" ) ;

                      System.exit ( 0 ) ;
                  }
                  else {

                      // add for log4j: log a message with the warn level
                      logger.warn ( "Command '" 
+ clientRequest + "' not understood." ) ;

                      writer.println ( "Command '"
+ clientRequest + "' not understood." ) ;
                  }
              }
          } catch ( IOException e ) {

              // add for log4j: log a message with the error level
              logger.error( "IOException in Server " + e ) ;

              System.exit ( 0 ) ;
          }
      }
}
}