genericrequestwrapper.java

icsamples目录中有icsamples网络程序。 这个程序包括J2EE网络层的范例程序

package jwadbook.filter;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.ServletInputStream;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;

public class GenericRequestWrapper extends HttpServletRequestWrapper
{ 
    private ByteArrayInputStream instream;
    private int contentLength;
    private String contentType;
    private Hashtable pratable = new Hashtable();
    private boolean logToFile = true;
    private String logFileName = "../logs/filterwapper.out";
    private FileOutputStream logFileOut=null;
    
    public GenericRequestWrapper(HttpServletRequest request)
    { 
	super(request);
	//instream=new ByteArrayInputStream();
    } 
    
    public String getParameter(String name) 
    {
	return (String)pratable.get(name);
    }
    
    public Map getParameterMap() 
    {
	return pratable;
    }
               
    public Enumeration getParameterNames()
    {
	return pratable.keys();
    }

    public String[] getParameterValues(String name)
    {
	log("Get ParameterValue:"+ name);
	String[] value = new String[1];
	value[0]= (String)pratable.get(name);
	log("Value Got: "+ value[0]);

	return value;
    }

    public void setParameterValue(String parameter, String value)
    {
	log("Set Parameter:"+parameter+" Value:"+ value);

	if (pratable.containsKey(parameter))
	    {
		pratable.remove(parameter);
	    }
	pratable.put(parameter, value);
    }

  /***********************************************************
     * Log a message to the servlet context application log.
     *
     * @param message Message to be logged
     **********************************************************/

    protected void log(String message) {

	try
	    {
		if ( logToFile==true )
		    {
			if ( logFileOut == null )
			    {
				logFileOut = new FileOutputStream( logFileName );
			    }
			  
			logFileOut.write( ("Request Wrapper: " + message).getBytes());
			logFileOut.write ( "\n".getBytes());
		    }

		System.out.println("Request Wrapper: " + message);

	    }
		catch (Exception e )
		{
			System.out.println("Exception occured : " + e );
		}
    }


    /*******************************************************************
     * Log a message and associated exception to the servlet context
     * application log.
     *
     * @param message Message to be logged
     * @param throwable Exception to be logged
     ******************************************************************/

    protected void log(String message, Throwable throwable) {
		
	try
	    {
		if ( logToFile==true )
		    {
			if ( logFileOut == null )
			      {
				  logFileOut = new FileOutputStream( logFileName, true );
			      }
			  
			logFileOut.write( ("Request Wrapper: " + message).getBytes() );
			logFileOut.write ( "\n".getBytes() );
		    }
		System.out.println("Request Wrapper: " + message);
		throwable.printStackTrace(System.out);
	    }
	catch (Exception e )
	    {
		System.out.println("Exception occured : " + e );
	    }

    }    
   
}