clientwithlog4j.java

log4j的基本功能的实现包括属性文件的配置

package log4j;
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> Client With Log4j </p>
* <p> Description: a sample with log4j</p>
* @version 1.0
*/
public class ClientWithLog4j {

/*
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 
( ClientWithLog4j.class.getName () ) ;

/**
   *
   * @param args : configuration file name
   */
public static void main ( String args [] ) {

      String welcome = null ;
      String response = null ;
      BufferedReader reader = null ;
      PrintWriter writer = null ;
      InputStream in = null ;
      OutputStream out = null ;
      Socket client = null ;

      /*
      add for log4j: class BasicConfigurator can quickly configure the package.
      print the information to console.
      */
      PropertyConfigurator.configure ( "Log4jProperty/ClientWithLog4j.properties" ) ;

      // add for log4j: set the level
//        logger.setLevel ( ( Level ) Level.DEBUG ) ;

      try{
          client = new Socket( "localhost" , 8001 ) ;

          // add for log4j: log a message with the info level
          logger.info ( "Client socket: " + client ) ;

          in = client.getInputStream () ;
          out = client.getOutputStream () ;
      } catch ( IOException e ) {

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

          System.exit ( 0 ) ;
      }

      try{
          reader = new BufferedReader ( new InputStreamReader ( in ) ) ;
          writer = new PrintWriter ( new OutputStreamWriter ( out ), true ) ;

          welcome = reader.readLine () ;

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

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

          writer.println ( "HELLO" ) ;
          response = reader.readLine () ;

          // add for log4j: log a message with the debug level
          logger.debug ( "Server responds: '" + response + "'" ) ;

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

          writer.println ( "HELP" ) ;
          response = reader.readLine () ;

          // add for log4j: log a message with the debug level
          logger.debug ( "Server responds: '" + response + "'") ;

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

          writer.println ( "QUIT" ) ;
      } catch ( IOException e ) {

          // add for log4j: log a message with the warn level
          logger.warn ( "IOException in client.in.readln()" ) ;

          System.out.println ( e ) ;
      }
      try {
          Thread.sleep ( 2000 ) ;
      } catch ( Exception ignored ) {}
}
}