defaultservlet.java

业界著名的tomcat服务器的最新6.0的源代码。

    protected void doPut(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {

        if (readOnly) {
            resp.sendError(HttpServletResponse.SC_FORBIDDEN);
            return;
        }

        String path = getRelativePath(req);

        boolean exists = true;
        try {
            resources.lookup(path);
        } catch (NamingException e) {
            exists = false;
        }

        boolean result = true;

        // Temp. content file used to support partial PUT
        File contentFile = null;

        Range range = parseContentRange(req, resp);

        InputStream resourceInputStream = null;

        // Append data specified in ranges to existing content for this
        // resource - create a temp. file on the local filesystem to
        // perform this operation
        // Assume just one range is specified for now
        if (range != null) {
            contentFile = executePartialPut(req, range, path);
            resourceInputStream = new FileInputStream(contentFile);
        } else {
            resourceInputStream = req.getInputStream();
        }

        try {
            Resource newResource = new Resource(resourceInputStream);
            // FIXME: Add attributes
            if (exists) {
                resources.rebind(path, newResource);
            } else {
                resources.bind(path, newResource);
            }
        } catch(NamingException e) {
            result = false;
        }

        if (result) {
            if (exists) {
                resp.setStatus(HttpServletResponse.SC_NO_CONTENT);
            } else {
                resp.setStatus(HttpServletResponse.SC_CREATED);
            }
        } else {
            resp.sendError(HttpServletResponse.SC_CONFLICT);
        }

    }


    /**
     * Handle a partial PUT.  New content specified in request is appended to
     * existing content in oldRevisionContent (if present). This code does
     * not support simultaneous partial updates to the same resource.
     */
    protected File executePartialPut(HttpServletRequest req, Range range,
                                     String path)
        throws IOException {

        // Append data specified in ranges to existing content for this
        // resource - create a temp. file on the local filesystem to
        // perform this operation
        File tempDir = (File) getServletContext().getAttribute
            ("javax.servlet.context.tempdir");
        // Convert all '/' characters to '.' in resourcePath
        String convertedResourcePath = path.replace('/', '.');
        File contentFile = new File(tempDir, convertedResourcePath);
        if (contentFile.createNewFile()) {
            // Clean up contentFile when Tomcat is terminated
            contentFile.deleteOnExit();
        }

        RandomAccessFile randAccessContentFile =
            new RandomAccessFile(contentFile, "rw");

        Resource oldResource = null;
        try {
            Object obj = resources.lookup(path);
            if (obj instanceof Resource)
                oldResource = (Resource) obj;
        } catch (NamingException e) {
            ;
        }

        // Copy data in oldRevisionContent to contentFile
        if (oldResource != null) {
            BufferedInputStream bufOldRevStream =
                new BufferedInputStream(oldResource.streamContent(),
                                        BUFFER_SIZE);

            int numBytesRead;
            byte[] copyBuffer = new byte[BUFFER_SIZE];
            while ((numBytesRead = bufOldRevStream.read(copyBuffer)) != -1) {
                randAccessContentFile.write(copyBuffer, 0, numBytesRead);
            }

            bufOldRevStream.close();
        }

        randAccessContentFile.setLength(range.length);

        // Append data in request input stream to contentFile
        randAccessContentFile.seek(range.start);
        int numBytesRead;
        byte[] transferBuffer = new byte[BUFFER_SIZE];
        BufferedInputStream requestBufInStream =
            new BufferedInputStream(req.getInputStream(), BUFFER_SIZE);
        while ((numBytesRead = requestBufInStream.read(transferBuffer)) != -1) {
            randAccessContentFile.write(transferBuffer, 0, numBytesRead);
        }
        randAccessContentFile.close();
        requestBufInStream.close();

        return contentFile;

    }


    /**
     * Process a POST request for the specified resource.
     *
     * @param req The servlet request we are processing
     * @param resp The servlet response we are creating
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet-specified error occurs
     */
    protected void doDelete(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {

        if (readOnly) {
            resp.sendError(HttpServletResponse.SC_FORBIDDEN);
            return;
        }

        String path = getRelativePath(req);

        boolean exists = true;
        try {
            resources.lookup(path);
        } catch (NamingException e) {
            exists = false;
        }

        if (exists) {
            boolean result = true;
            try {
                resources.unbind(path);
            } catch (NamingException e) {
                result = false;
            }
            if (result) {
                resp.setStatus(HttpServletResponse.SC_NO_CONTENT);
            } else {
                resp.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
            }
        } else {
            resp.sendError(HttpServletResponse.SC_NOT_FOUND);
        }

    }


    /**
     * Check if the conditions specified in the optional If headers are
     * satisfied.
     *
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     * @param resourceAttributes The resource information
     * @return boolean true if the resource meets all the specified conditions,
     * and false if any of the conditions is not satisfied, in which case
     * request processing is stopped
     */
    protected boolean checkIfHeaders(HttpServletRequest request,
                                     HttpServletResponse response,
                                     ResourceAttributes resourceAttributes)
        throws IOException {

        return checkIfMatch(request, response, resourceAttributes)
            && checkIfModifiedSince(request, response, resourceAttributes)
            && checkIfNoneMatch(request, response, resourceAttributes)
            && checkIfUnmodifiedSince(request, response, resourceAttributes);

    }


    /**
     * Get the ETag associated with a file.
     *
     * @param resourceAttributes The resource information
     */
    protected String getETag(ResourceAttributes resourceAttributes) {
        String result = null;
        if ((result = resourceAttributes.getETag(true)) != null) {
            return result;
        } else if ((result = resourceAttributes.getETag()) != null) {
            return result;
        } else {
            return "W/\"" + resourceAttributes.getContentLength() + "-"
                + resourceAttributes.getLastModified() + "\"";
        }
    }


    /**
     * URL rewriter.
     *
     * @param path Path which has to be rewiten
     */
    protected String rewriteUrl(String path) {
        return urlEncoder.encode( path );
    }


    /**
     * Display the size of a file.
     */
    protected void displaySize(StringBuffer buf, int filesize) {

        int leftside = filesize / 1024;
        int rightside = (filesize % 1024) / 103;  // makes 1 digit
        // To avoid 0.0 for non-zero file, we bump to 0.1
        if (leftside == 0 && rightside == 0 && filesize != 0)
            rightside = 1;
        buf.append(leftside).append(".").append(rightside);
        buf.append(" KB");

    }


    /**
     * Serve the specified resource, optionally including the data content.
     *
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     * @param content Should the content be included?
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet-specified error occurs
     */
    protected void serveResource(HttpServletRequest request,
                                 HttpServletResponse response,
                                 boolean content)
        throws IOException, ServletException {

        // Identify the requested resource path
        String path = getRelativePath(request);
        if (debug > 0) {
            if (content)
                log("DefaultServlet.serveResource:  Serving resource '" +
                    path + "' headers and data");
            else
                log("DefaultServlet.serveResource:  Serving resource '" +
                    path + "' headers only");
        }

        CacheEntry cacheEntry = resources.lookupCache(path);

        if (!cacheEntry.exists) {
            // Check if we're included so we can return the appropriate 
            // missing resource name in the error
            String requestUri = (String) request.getAttribute(
                                            Globals.INCLUDE_REQUEST_URI_ATTR);
            if (requestUri == null) {
                requestUri = request.getRequestURI();
            } else {
                // We're included, and the response.sendError() below is going
                // to be ignored by the resource that is including us.
                // Therefore, the only way we can let the including resource
                // know is by including warning message in response
                response.getWriter().write(
                    sm.getString("defaultServlet.missingResource",
                    requestUri));
            }

            response.sendError(HttpServletResponse.SC_NOT_FOUND,
                               requestUri);
            return;
        }

        // If the resource is not a collection, and the resource path
        // ends with "/" or "\", return NOT FOUND
        if (cacheEntry.context == null) {
            if (path.endsWith("/") || (path.endsWith("\\"))) {
                // Check if we're included so we can return the appropriate 
                // missing resource name in the error
                String requestUri = (String) request.getAttribute(
                                            Globals.INCLUDE_REQUEST_URI_ATTR);
                if (requestUri == null) {
                    requestUri = request.getRequestURI();
                }
                response.sendError(HttpServletResponse.SC_NOT_FOUND,
                                   requestUri);
                return;
            }
        }

        // Check if the conditions specified in the optional If headers are
        // satisfied.
        if (cacheEntry.context == null) {

            // Checking If headers
            boolean included =
                (request.getAttribute(Globals.INCLUDE_CONTEXT_PATH_ATTR) != null);
            if (!included
                && !checkIfHeaders(request, response, cacheEntry.attributes)) {
                return;
            }

        }

        // Find content type.
        String contentType = cacheEntry.attributes.getMimeType();
        if (contentType == null) {
            contentType = getServletContext().getMimeType(cacheEntry.name);
            cacheEntry.attributes.setMimeType(contentType);
        }

        ArrayList ranges = null;
        long contentLength = -1L;

        if (cacheEntry.context != null) {

            // Skip directory listings if we have been configured to
            // suppress them
            if (!listings) {
                response.sendError(HttpServletResponse.SC_NOT_FOUND,
                                   request.getRequestURI());
                return;
            }
            contentType = "text/html;charset=UTF-8";

        } else {

            // Parse range specifier

            ranges = parseRange(request, response, cacheEntry.attributes);

            // ETag header
            response.setHeader("ETag", getETag(cacheEntry.attributes));

            // Last-Modified header
            response.setHeader("Last-Modified",
                    cacheEntry.attributes.getLastModifiedHttp());

            // Get content length
            contentLength = cacheEntry.attributes.getContentLength();
            // Special case for zero length files, which would cause a
            // (silent) ISE when setting the output buffer size
            if (contentLength == 0L) {
                content = false;
            }

        }

        ServletOutputStream ostream = null;
        PrintWriter writer = null;

        if (content) {