I'm trying to find the simplest way to parse an RFC-822 document in Java. Assume that I have a message-queue on which HTTP messages are stored. Both requests and responses. So they are not retrieved in the "normal" way by making a socket-connection to - say - port 80 and sending/retrieving the message from there.
In the code below, I deliberately mixed "mail" headers with a HTTP message. It's meant as a demonstration that the two are not very different. But that's beside the point. Here's the code:
package httpexample;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import org.apache.http.Header;
import org.apache.http.HttpException;
import org.apache.http.HttpRequest;
import org.apache.http.impl.io.DefaultHttpRequestParser;
import org.apache.http.impl.io.HttpTransportMetricsImpl;
import org.apache.http.impl.io.SessionInputBufferImpl;
import org.apache.http.io.HttpMessageParser;
import org.apache.http.message.BasicHttpEntityEnclosingRequest;
public class HttpExample {
// RFC 822
public static void main(String[] args) throws IOException, HttpException {
String str = "POST http://localhost:8080/foobar/1234567 HTTP/1.1\n" +
"Message-ID: <19815303.1075861029555.JavaMail.ss@kk>\n" +
"Date: Wed, 6 Mar 2010 12:32:20 -0800 (PST)\n" +
"From: [email protected]\n" +
"To: [email protected]\n" +
"Subject: some subject\n" +
"Mime-Version: 1.0\n" +
"Content-Type: text/plain; charset=us-ascii\n" +
"Content-Transfer-Encoding: 7bit\n" +
"X-From: one, some <[email protected]>\n" +
"X-To: one\n" +
"X-cc: \n" +
"X-bcc: \n" +
"X-Origin: Bob-R\n" +
"X-FileName: rbob (Non-Privileged).pst\n" +
"\n" +
"some message\n";
ByteArrayInputStream fakeStream = new ByteArrayInputStream(
str.getBytes());
HttpTransportMetricsImpl metrics = new HttpTransportMetricsImpl();
SessionInputBufferImpl inbuffer = new SessionInputBufferImpl(metrics, 1024);
inbuffer.bind(fakeStream);
HttpMessageParser<HttpRequest> requestParser =
new DefaultHttpRequestParser(inbuffer);
BasicHttpEntityEnclosingRequest request = (BasicHttpEntityEnclosingRequest)requestParser.parse();
for (Header hdr : request.getAllHeaders()) {
System.out.println(String.format("%-30s = %s", hdr.getName(), hdr.getValue()));
}
System.out.println(String.format("Request Line: %s", request.getRequestLine()));
System.out.println(String.format("Body\n------------------\n%s",
request.getEntity()));
}
}
The output looks like this:
Message-ID = <19815303.1075861029555.JavaMail.ss@kk>
Date = Wed, 6 Mar 2010 12:32:20 -0800 (PST)
From = [email protected]
To = [email protected]
Subject = some subject
Mime-Version = 1.0
Content-Type = text/plain; charset=us-ascii
Content-Transfer-Encoding = 7bit
X-From = one, some <[email protected]>
X-To = one
X-cc =
X-bcc =
X-Origin = Bob-R
X-FileName = rbob (Non-Privileged).pst
Request Line: POST http://localhost:8080/foobar/1234567 HTTP/1.1
Body
------------------
null
What I can't figure out, is how to access the body of the message.
I would expect it to have the content some message\n
I can't find any method in BasicHttpEntityEnclosingRequest that would give me this value. In an earlier version I used
HttpRequest request = requestParser.parse();
instead of
BasicHttpEntityEnclosingRequest request =
(BasicHttpEntityEnclosingRequest) requestParser.parse();
I changed it to BasicHttpEntityEnclosingRequest because that has the getEntity method. But that returns null.
So I'm a bit lost.
Where do I find the body?
I have added Content-Length header, otherwise the parser simply ignores the POST body. I have modified your code, now it parses the body just fine:
package org.apache.http.examples;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import org.apache.http.Header;
import org.apache.http.HttpException;
import org.apache.http.message.BasicHttpEntityEnclosingRequest;
import org.apache.http.util.EntityUtils;
public class HttpExample {
// RFC 822
public static void main(String[] args) throws IOException, HttpException {
String str = "POST http://localhost:8080/foobar/1234567 HTTP/1.1\n" +
"Message-ID: <19815303.1075861029555.JavaMail.ss@kk>\n" +
"Date: Wed, 6 Mar 2010 12:32:20 -0800 (PST)\n" +
"From: [email protected]\n" +
"To: [email protected]\n" +
"Subject: some subject\n" +
"Mime-Version: 1.0\n" +
"Content-Type: text/plain; charset=us-ascii\n" +
"Content-Transfer-Encoding: 7bit\n" +
"X-From: one, some <[email protected]>\n" +
"X-To: one\n" +
"X-cc: \n" +
"X-bcc: \n" +
"X-Origin: Bob-R\n" +
"X-FileName: rbob (Non-Privileged).pst\n" +
"Content-Length: 13\n" +
"\n" +
"some message\n";
ByteArrayInputStream fakeStream = new ByteArrayInputStream(
str.getBytes());
BHttpConnectionBaseImpl b = new BHttpConnectionBaseImpl(fakeStream);
BasicHttpEntityEnclosingRequest request1 = (BasicHttpEntityEnclosingRequest) b.receiveRequestHeader();
b.receiveRequestEntity(request1);
for (Header hdr : request1.getAllHeaders()) {
System.out.println(String.format("%-30s = %s", hdr.getName(), hdr.getValue()));
}
System.out.println(String.format("Request Line: %s", request1.getRequestLine()));
System.out.println(String.format("Body\n------------------\n%s",
EntityUtils.toString( request1.getEntity() ) ));
}
}
class BHttpConnectionBaseImpl extends org.apache.http.impl.DefaultBHttpServerConnection{
private InputStream inputStream;
public BHttpConnectionBaseImpl(final InputStream inputStream) {
super(4048);
this.inputStream = inputStream;
try {
super.bind(new Socket());
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
protected InputStream getSocketInputStream(final Socket socket) throws IOException {
return inputStream;
}
@Override
protected OutputStream getSocketOutputStream(final Socket socket) throws IOException {
return new ByteArrayOutputStream();
}
}
The parsing of POST body happens in org.apache.http.impl.BHttpConnectionBase.prepareInput(HttpMessage), whoever its only constructor is protected and requires a lot of parameters. The child org.apache.http.impl.DefaultBHttpServerConnection has a convenient public constructor and does the header parsing in receiveRequestHeader(). The methods I'm overloading are need to bypass some error checks, e.g. if the Socket == null and to be able to read the request from the fakeStream
Another approach that might working, although I have not tested it, is to override Socket particularly its getInputStream() and getOutputStream(). Then create an instance of DefaultBHttpServerConnection and call its bind method. The rest should be the same.