httpframe.java

很棒的web服务器源代码

    }

    /**
     * Get the optional index name array for this directory listing.
     * @return The index name array (including the main index)
     * @see #getIndex
     */
    public String[] getIndexes() {
	String mainIndex = getIndex();
	if (mainIndex != null) {
	    String indexes[] = (String[]) getValue(ATTR_INDEXES, null);
	    if (indexes != null) {
		int    len          = indexes.length + 1;
		String mergeIndex[] = new String[len];
		mergeIndex[0] = mainIndex;
		System.arraycopy(indexes, 0, mergeIndex, 1, len-1);
		return mergeIndex;
	    } else {
		indexes = new String[1];
		indexes[0] = mainIndex;
		return indexes;
	    }
	} else {
	    return (String[]) getValue(ATTR_INDEXES, null) ;
	}
    }

    /**
     * Add our own Style Sheet to the HtmlGenerator.
     * @param g The HtmlGenerator.
     */
    public void addStyleSheet(HtmlGenerator g) {
	// Add style link
	String css_url = getStyleSheetURL();
	if (css_url != null) {
	    g.addLink( new HtmlLink("STYLESHEET", css_url));
	}
    }

    /**
     * Get ContainerResource listing
     * @param refresh should we refresh the listing?
     * @return a boolean (true if refreshed)
     */ 
    public boolean computeContainerListing(boolean refresh) {
	ContainerResource cresource = (ContainerResource)resource;
	synchronized (cresource) {
	    if ((refresh) ||
	        (listing == null) || 
		(cresource.getLastModified() > listing_stamp) || 
		(getLastModified() > listing_stamp)) {
	    
		Class http_class = null;
		try {
		    http_class = 
			    Class.forName("org.w3c.jigsaw.frames.HTTPFrame");
		} catch (ClassNotFoundException ex) {
			http_class = null;
		}

		Enumeration   enum  = cresource.enumerateResourceIdentifiers();
		Vector    resources = Sorter.sortStringEnumeration(enum) ;
		HtmlGenerator g     = 
		      new HtmlGenerator("Index of "+cresource.getIdentifier());
		// Add style link
		addStyleSheet(g);
		g.append("<h1>"+cresource.getIdentifier()+"</h1>");
		// Link to the parent, when possible:
		if ( cresource.getParent() != null ) {
		    g.append("<p><a href=\"..\">Parent</a><br>");
		}
	    // List the children:
		for (int i = 0 ; i < resources.size() ; i++) {
		    String            name = (String) resources.elementAt(i);
		    ResourceReference rr   = null;
		    long              size = -1;
		    rr = cresource.lookup(name);
		    FramedResource resource = null;
		    if (rr != null) {
			try {
			    resource = (FramedResource) rr.unsafeLock();
			    // remove manually deleted FileResources
			    if( resource instanceof FileResource ) {
			        FileResource fr = (FileResource)resource;
				if( !fr.getFile().exists() ) {
				    try {
					fr.delete();
				    } catch (MultipleLockException ex) {};
				    continue;
				} else {
					size = fr.getFile().length();
				}
			    }
			    HTTPFrame itsframe = null;
			    if (http_class != null)
				itsframe = 
				    (HTTPFrame) resource.getFrame(http_class);
			    if (itsframe != null) {
				// Icon first, if available
				String icon = itsframe.getIcon() ;
				if ( icon != null ) {
				    g.append("<img src=\""+
					     getIconDirectory() +"/"+ icon+
					     "\" alt=\"" + icon + "\">");
				}
				// Resource's name with link:
				if (resource instanceof ContainerInterface) {
				    g.append("<a href=\"" 
					     , URLEncoder.encode(name)
					     , "/\">"+name+"</a>");
				} else {
				    g.append("<a href=\"" 
					     , URLEncoder.encode(name)
					     , "\">"+name+"</a>");
				}
				// resource's title, if any:
				String title = itsframe.getTitle();
				if ( title != null ) {
				    g.append(" "+title);
				}
				//size (if any)
				if (size != -1) {
				    String s = null;
				    if (size > 1023) {
					s = " ["+(size/1024)+" Kb]";
				    } else {
					s = " ["+size+" bytes]";
				    }
				    g.append(s);
				}
				g.append("<br>\n");
			    } else {
				// Resource's name with link:
				g.append(name+
					 " (<i>Not available via HTTP.</i>)");
				g.append("<br>\n");
			    }
			} catch (InvalidResourceException ex) {
			    g.append(name+
				  " cannot be loaded (server misconfigured)");
			    g.append("<br>\n");
			    continue;
			} finally { 
			    rr.unlock();
			}
		    }
		}
		g.close() ;
		listing_stamp = getLastModified() ;
		listing       = g ;
		return true;
	    }
	}
	return false;
    }

    /**
     * Reply with an HTML doc listing the resources of this container.
     * This function takes special care not to regenerate a listing
     * when one is available. It also caches the date of the
     * listing, so that it can win big with NOT_MODIFIED.
     * <p>Using a modem, I know that each place I can reply with an 
     * NOT_MODIFIED, <strong>is</strong> a big win.
     * @param request The request to handle.
     * @exception ProtocolException If processsing the request failed.
     * @exception ResourceException If the resource got a fatal error.
     */

    public Reply getDirectoryListing(Request request)
	throws ProtocolException, ResourceException
    {
	if (! (resource instanceof ContainerResource)) {
	    throw new ResourceException("this frame is not attached to a "+
					"ContainerResource. ("+
					resource.getIdentifier()+")");
	}
	// delete us if the directory was deleted
	boolean refresh = false;
	if (dresource != null) {
	    synchronized (dresource) {
	        if (! dresource.getDirectory().exists()) {
	   	    //delete us and emit an error
		    String msg = dresource.getIdentifier()+
		        ": deleted, removing the DirectoryResource";
		    getServer().errlog(dresource, msg);
		    try {
		        dresource.delete();
		    } catch (MultipleLockException ex) {
		    }
		    // Emit an error back:
		    Reply error = request.makeReply(HTTP.NOT_FOUND) ;
		    error.setContent ("<h1>Document not found</h1>"+
			   	      "<p>The document "+
				      request.getURL()+
				      " is indexed but not available."+
				      "<p>The server is misconfigured.") ;
		    throw new HTTPException (error) ;
		}
		refresh = 
			(dresource.getDirectory().lastModified() > 
			                                       listing_stamp);
	    }
	}
	if ((! computeContainerListing(refresh)) && 
	    ( checkIfModifiedSince(request) == COND_FAILED )) {
	    // Is it an IMS request ?
	    Reply reply = createDefaultReply(request, HTTP.NOT_MODIFIED) ;
	    return reply;
	}
	// New content or need update:
	Reply reply = createDefaultReply(request, HTTP.OK) ;
	reply.setLastModified(listing_stamp) ;
	reply.setStream(listing) ;
	// check MD5
	return reply ;
    }

    //
    // Commom part.
    //

    /**
     * Update the cached headers value.
     * Each resource maintains a set of cached values for headers, this
     * allows for a nice sped-up in headers marshalling, which - as the 
     * complexity of the protocol increases - becomes a bottleneck.
     */

    protected void updateCachedHeaders() {
	// Precompute a set of header values to keep by:
	if ( contenttype == null ) {
	    String charset = getCharset();
	    if (charset == null)
		contenttype = HttpFactory.makeMimeType(getContentType());
	    else {
		MimeType ctype = getContentType().getClone();
		ctype.addParameter("charset", charset);
		contenttype = HttpFactory.makeMimeType(ctype);
	    }
	}
	if (contentlength == null) {
	    int cl = -1;
	    if (fresource != null) 
		cl = fresource.getFileLength();
	    if ( cl >= 0 ) {
		if (cl != getInt(ATTR_CONTENT_LENGTH, -1)) {
		    setValue(ATTR_CONTENT_LENGTH, new Integer(cl));
		}
		contentlength = HttpFactory.makeInteger(cl);
	    }
	}
	if ( lastmodified == null ) {
	    long lm = getLastModified();
	    if ( lm > 0 )
		lastmodified = HttpFactory.makeDate(getLastModified());
	}
	if (definesAttribute(ATTR_CONTENT_ENCODING) &&(contentencoding==null))
	    contentencoding = HttpFactory.makeStringList(getContentEncoding());
	if (definesAttribute(ATTR_CONTENT_LANGUAGE) &&(contentlanguage==null))
	    contentlanguage = HttpFactory.makeStringList(getContentLanguage());

	if (fresource != null) {
	    // We only take care of etag here:
	    if ( etag == null ) {
		getETag();
	    }
	    if (getMD5Flag() && (md5Digest == null)) {
		getMd5Digest();
	    }
	}
    }

    /**
     * Create a reply to answer to request on this file.
     * This method will create a suitable reply (matching the given request)
     * and will set all its default header values to the appropriate 
     * values.
     * @param request The request to make a reply for.
     * @return An instance of Reply, suited to answer this request.
     */

    public Reply createDefaultReply(Request request, int status) {
	Reply reply = request.makeReply(status);
	updateCachedHeaders();
	if ( status != HTTP.NOT_MODIFIED ) {
	    if ( contentlength != null )
		reply.setHeaderValue(Reply.H_CONTENT_LENGTH, contentlength);
	    if ( contenttype != null )
		reply.setHeaderValue(Reply.H_CONTENT_TYPE, contenttype);
	    if ( lastmodified != null )
		reply.setHeaderValue(Reply.H_LAST_MODIFIED, lastmodified);
	    if ( contentencoding != null ) {
		reply.setHeaderValue(Reply.H_CONTENT_ENCODING,contentencoding);
	    }
	    if ( contentlanguage != null )
		reply.setHeaderValue(Reply.H_CONTENT_LANGUAGE,contentlanguage);

	}
	long maxage = getMaxAge();
	if ( maxage >= 0 ) {
	    if (reply.getMajorVersion() >= 1 ) {
		if (reply.getMinorVersion() >= 1) {
		    reply.setMaxAge((int) (maxage / 1000));
		} 
		// If max-age is zero, say what you mean:
		long expires = (System.currentTimeMillis()
				+ ((maxage == 0) ? -1000 : maxage));
		reply.setExpires(expires);
	    }
	}
	// Set the date of the reply (round it to secs):
	reply.setDate((System.currentTimeMillis() / 1000L) * 1000L);

	if (fresource != null) {
	    // Set the entity tag:
	    if ( getETag() != null ) {
		reply.setETag(etag);
	    }
	    if ( status != HTTP.NOT_MODIFIED ) {
		if ( acceptRanges ) {
		    reply.setHeaderValue(reply.H_ACCEPT_RANGES,_accept_ranges);
		}
		if ( getMD5Flag()) {
		    reply.setHeaderValue(reply.H_CONTENT_MD5, getMd5Digest());
		}
	    }
	}
	return reply;
    }

    /**
     * Check the <code>If-Match</code> condition of that request.
     * @param request The request to check.
     * @return An integer, either <code>COND_FAILED</cond> if condition
     * was checked, but failed, <code>COND_OK</code> if condition was checked
     * and succeeded, or <strong>0</strong> if the condition was not checked
     * at all (eg because the resource or the request didn't support it).
     */

    public int checkIfMatch(Request request) {
	if (fresource != null) {
	    HttpEntityTag tags[] = request.getIfMatch();
	    if ( tags != null ) {
		// Good, real validators in use:
		if ( etag != null ) {
		    // Note: if etag is null this means that the resource has 
		    // changed and has not been even emited since then...
		    for (int i = 0 ; i < tags.length ; i++) {
			HttpEntityTag t = tags[i];
			if (t.getTag().equals(etag.getTag())) {
			    if (t.isWeak() || etag.isWeak()) {
				return COND_WEAK;
			    } else {
				return COND_OK;
			    }
			}
		    }
		}
		return COND_FAILED;
	    }
	}
	return 0;
    }

    /**
     * Check the <code>If-None-Match</code> condition of that request.
     * @param request The request to check.
     * @return An integer, either <code>COND_FAILED</cond> if condition
     * was checked, but failed, <code>COND_OK</code> if condition was checked
     * and succeeded, or <strong>0</strong> if the condition was not checked
     * at all (eg because the resource or the request didn't support it).
     */

    public int checkIfNoneMatch(Request request) {
	if (fresource != null) {
	    // Check for an If-None-Match conditional:
	    HttpEntityTag tags[] = request.getIfNoneMatch();
	    if ( tags != null ) {
		if ( etag == null ) {
		    return COND_OK;
		}
		int status = COND_OK;
		for (int i = 0 ; i < tags.length ; i++) {
		    HttpEntityTag t = tags[i];
		    if (t.getTag().equals(etag.getTag())) {
			if (t.isWeak() || etag.isWeak()) {
			    status = COND_WEAK;
			} else {
			    return COND_FAILED;
			}
		    }
		    if (t.getTag().equals("*")) {
			if (fresource != null) {
			    File f = fresource.getFile();
			    if (f.exists()) {
				return COND_FAILED;
			    }
			} else {
			    return COND_FAILED;
			}
		    }
		}
		return status;
	    }
	}
	return 0;
    }

    /**
     * Check the <code>If-Modified-Since</code> condition of that request.
     * @param request The request to check.
     * @return An integer, either <code>COND_FAILED</cond> if condition
     * was checked, but failed, <code>COND_OK</code> if condition was checked
     * and succeeded, or <strong>0</strong> if the condition was not checked
     * at all (eg because the resource or the request didn't support it).
     */

    public int checkIfModifiedSince(Request request) {
	// Check for an If-Modified-Since conditional:
	long ims = request.getIfModifiedSince();
	if (dresource != null) {
	    if (ims >= 0) {
		if (listing_stamp > 0) {
		    long s_listing_stamp = listing_stamp / 1000;
		    long s_ims = ims / 1000;
		    if (s_listing_stamp < s_ims) {
			return COND_FAILED;
		    } else if (s_listing_stamp == s_ims) {
			return COND_WEAK;