genericresponsewrapper.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.ServletOutputStream;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.http.*;
import java.io.*;

public class GenericResponseWrapper extends HttpServletResponseWrapper
{ 
    private ByteArrayOutputStream outstream;

    //this outputstream seperates the response outputstream
    

    private int contentLength;
    private String contentType;
    
    public GenericResponseWrapper(HttpServletResponse response)
    { 
	super(response);
	outstream=new ByteArrayOutputStream();
    } 

    public byte[] output()
    {
	return outstream.toByteArray();
    }

    public ServletOutputStream getOutputStream()
    {
	//instead of returning getOutputStream() on the wrapped response object.
	return new FilterServletOutputStream(outstream);
    }

    public PrintWriter getWriter()
    {
	return new PrintWriter(getOutputStream(), true);
    }
    
    public void setContentLength(int length)
    {
	this.contentLength = length;
	super.setContentLength(length);
    }
    
    public int getContentLength()
    {
	return contentLength;
    }

    public void setContentType(String type)
    {
	this.contentType = type;
	super.setContentType(type);
    }

    public String getContentType()
    {
	return contentType;
    }
    
}