httpurlconnection.java

来自「很棒的web服务器源代码」· Java 代码 · 共 277 行

// HttpURLConnection.java
// $Id: HttpURLConnection.java,v 1.20 2002/07/25 17:45:29 ylafon Exp $
// (c) COPYRIGHT MIT and INRIA, 1996.
// Please first read the full copyright statement in file COPYRIGHT.html

package org.w3c.www.protocol.http ;

import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import java.util.Enumeration;

import org.w3c.www.mime.MimeType;

import org.w3c.www.http.HeaderDescription;
import org.w3c.www.http.HttpEntityMessage;
import org.w3c.www.http.HttpMessage;
import org.w3c.www.http.HttpReplyMessage;
import org.w3c.www.http.HttpRequestMessage;

public class HttpURLConnection extends java.net.HttpURLConnection 
{
    protected Request               request = null;
    protected Reply                 reply   = null;
    protected ByteArrayOutputStream output  = null;

    protected final synchronized void checkRequest() {
	if ( request == null ) {
	    request = HttpManager.getManager().createRequest();
	    request.setMethod(method);
	    if ( ifModifiedSince > 0 )
		request.setIfModifiedSince(ifModifiedSince*1000);
	    if ( ! useCaches ) {
		request.addPragma("no-cache");
		request.setNoCache();
	    }
	    request.setURL(url);
	}
    }

    protected final void checkReply() {
	if ((reply == null) && connected) {
	    error("Was connected but didn't get any reply !");
	} else if ( ! connected ) {
	    try {
		connect();
	    } catch (IOException ex) {
		ex.printStackTrace();
		error("Error while silently connecting.");
	    }
	}
    }

    protected void error(String msg) {
	debug("ERROR \""+msg+"\"");
	throw new RuntimeException(msg);
    }

    protected final void debug(String m) {
	//	System.out.println("[http]: "
	//		   + ((request != null)
	//	           ? ":"+request.getURL().toExternalForm()+"]: "
	//  	           : "]: ")
	//		   + m);
    }

    public boolean usingProxy() {
	return HttpManager.getManager().usingProxy();
    }

    public synchronized void disconnect() {
	if ( request != null )
	    request.interruptRequest();
    }

    public void connect() 
	throws IOException
    {
	// Check if we have already connected ourself:
	debug("connect");
	if ( connected )
	    return;
	// Check for a valid request, and update stream if needed:
	checkRequest();
	if ( doOutput ) {
	    byte                 data[] = output.toByteArray();
	    ByteArrayInputStream in     = new ByteArrayInputStream(data);
	    request.setOutputStream(in);
	    if ( ! request.hasHeader(Request.H_CONTENT_LENGTH) )
		request.setContentLength(data.length);
	    if ( ! request.hasHeader(Request.H_CONTENT_TYPE) ) {
		MimeType t = (request.getMethod().equals("POST")
			      ? MimeType.APPLICATION_X_WWW_FORM_URLENCODED
			      : MimeType.TEXT_PLAIN);
		request.setContentType(t);
	    }
	}
	try {
	    // Run the reply, handling redirection:
	    int redirects = 0;
	  redir:
	    while ( redirects < 5 ) {
		if ( redirects == 1 ) {
		    // Reinit the request, cope with URLConnnection brokeness
		    request.setOutputStream(null);
		    request.setContentLength(-1);
		    request.setMethod("GET");
		}
		reply = request.getManager().runRequest(request);
		// Take care of redirects:
		if ((reply.getStatus() / 100) == 3) {
		    String reloc = reply.getLocation();
		    if ( reloc == null )
			break redir;
		    reply.getInputStream().close();
		    URL orig = request.getURL();
		    try {
			url = new URL(orig, reloc);
			request.setURL(url);
		    } catch (MalformedURLException ex) {
			break redir;
		    }
		} else {
		    break redir;
		}
		if ( ! getFollowRedirects() )
		    break redir;
		redirects++;
	    }
	} catch (HttpException ex) {
	    ex.printStackTrace();
	    throw new IOException(ex.getMessage());
	}
	connected = true;
    }

    public int getResponseCode() 
	throws IOException
    {
	checkReply();
	return reply.getStatus();
    }

    public int getContentLength() {
	checkReply();
	return reply.getContentLength();
    }

    public String getContentType() {
	checkReply();
	MimeType t = reply.getContentType();
	if (t == null) {
	    return null;
	}
	return t.toString();
    }
    
    public long getExpiration() {
	checkReply();
	return reply.getExpires();
    }

    public long getDate() {
	checkReply();
	return reply.getDate();
    }

    public long getLastModified() {
	checkReply();
	return reply.getLastModified();
    }

    public String getHeaderField(String name) {
	checkReply();
	return reply.getValue(name);
    }

    public String getHeaderFieldKey(int n) {
	Enumeration       e = reply.enumerateHeaderDescriptions(true);
	HeaderDescription d = null;
	while ( --n >= 0 ) {
	    if ( e.hasMoreElements() )
		d = (HeaderDescription) e.nextElement();
	    return null;
	}
	if ( d != null ) 
	    return d.getName();
	return null; 
    }

    public String getHeaderField(int n) {
	String key = getHeaderFieldKey(n);
	if ( key != null )
	    return reply.getValue(key);
	return null;
    }

    public InputStream getInputStream() 
	throws IOException
    {
	debug("getInputStream");
	checkReply();
	return reply.getInputStream();
    }

    public OutputStream getOutputStream() 
	throws IOException
    {
	debug("getOutputStream");
	// We can still catch some of the deficiencies here:
	if ((! connected) && (! doOutput)) {
	    setDoOutput(true);
	} else if ( connected ) {
	    error("Already connected, too late for getOutputStream.");
	}
	// Now return a fake output stream:
	// I am really ashame of this (having to buffer the data before 
	// emiting it), but I cannot see any better way of using this
	// broken API (?)
	output = new ByteArrayOutputStream();
	return output;
    }

    public InputStream getErrorStream() {
	debug("getErrorStream");
	try {
	    int errorCat = reply.getStatus()/100 ;
	    if (connected && (errorCat == 4 || errorCat == 5)) {
		return reply.getInputStream() ;
	    }
	    // the next catch the case where there is no reply
	    // as well as errors while handling the reply (no useful info...)
	} catch (Exception ex) {
	    return null;
	}
	return null;
    }

    public void setRequestProperty(String key, String value) {
	checkRequest();
	request.setValue(key, value);
    }

    public String getRequestProperty(String key) {
	checkRequest();
	return request.getValue(key);
    }
	
    public static void setGlobalRequestProperty(String key, String value) {
	HttpManager.getManager().setGlobalHeader(key, value);
    }

    public static String getDefaultRequestProperty(String key) {
	return HttpManager.getManager().getGlobalHeader(key);
    }

    public void setDoOutput(boolean doinput) {
	debug("DoOutput !!");
	super.setDoOutput(doinput);
	checkRequest();
	if ( request.getContentType() == null )
	    request.setContentType(MimeType.APPLICATION_X_WWW_FORM_URLENCODED);
    }

    HttpURLConnection(URL u) {
	super(u) ;
    }

}