RequestReader.java

package com.buglabs.osgi.sewing.pub.util;

import java.io.IOException;
import java.io.InputStream;
import javax.servlet.http.HttpServletRequest;
import org.osgi.service.log.LogService;
import com.buglabs.osgi.sewing.LogManager;

/**
 * A static class to abstract the reading of the body of a request object
 * @author bballantine
 * 
 * UPDATES: 
 * AK 2010-08-17: added a check if content length header is null 
 */
public class RequestReader {

	private static final int MAX_BYTES = 3 * 1024 * 1024; // megabytes
	private static final int MAX_TRIES = 10;
	private static final int MILLISECONDS_WAIT = 10;
	private static final String CONTENT_LENGTH = "Content-Length";

	public static String read(HttpServletRequest req) throws IOException {
		StringBuffer sbuf = new StringBuffer();
		
		int contentLength = MAX_BYTES;
		String contentLengthHeader = req.getHeader(CONTENT_LENGTH); 
		if (contentLengthHeader != null) {
			try {			
				contentLength = Integer.parseInt(contentLengthHeader);
			} catch (NumberFormatException e) {
				LogManager.log(LogService.LOG_DEBUG, "Unable to get content length of multipart body.", e);
			}
		}
		
		InputStream istream = req.getInputStream();
		int r, tries =0, numread = 0;
		while (tries < MAX_TRIES && numread<contentLength) {
			if ((r = istream.read()) >= 0) {
				sbuf.append((char) r);
				++numread;
				tries = 0;
			} else {
				try { Thread.sleep(MILLISECONDS_WAIT); } 
				catch (InterruptedException e) {}
				++tries;
			}
		}
		
		return sbuf.toString();
	}

}