ssiservletexternalresolver.java

业界著名的tomcat服务器的最新6.0的源代码。

                // If this is an error page, get the original URI
                retVal = (String) req.getAttribute(
                        "javax.servlet.forward.request_uri");
                if (retVal == null) retVal=req.getRequestURI();
            }
        } else if (nameParts[0].equals("SCRIPT")) {
            String scriptName = req.getServletPath();
            if (nameParts[1].equals("FILENAME")) {
                retVal = context.getRealPath(scriptName);
            }
            else if (nameParts[1].equals("NAME")) {
                retVal = scriptName;
            }
        } else if (nameParts[0].equals("SERVER")) {
            if (nameParts[1].equals("ADDR")) {
                retVal = req.getLocalAddr();
            }
            if (nameParts[1].equals("NAME")) {
                retVal = req.getServerName();
            } else if (nameParts[1].equals("PORT")) {
                retVal = Integer.toString(req.getServerPort());
            } else if (nameParts[1].equals("PROTOCOL")) {
                retVal = req.getProtocol();
            } else if (nameParts[1].equals("SOFTWARE")) {
                StringBuffer rv = new StringBuffer(context.getServerInfo());
                rv.append(" ");
                rv.append(System.getProperty("java.vm.name"));
                rv.append("/");
                rv.append(System.getProperty("java.vm.version"));
                rv.append(" ");
                rv.append(System.getProperty("os.name"));
                retVal = rv.toString();
            }
        } else if (name.equalsIgnoreCase("UNIQUE_ID")) {
            retVal = req.getRequestedSessionId();
        }
        if (requiredParts != nameParts.length) return null;
            return retVal;
    }

    public Date getCurrentDate() {
        return new Date();
    }


    protected String nullToEmptyString(String string) {
        String retVal = string;
        if (retVal == null) {
            retVal = "";
        }
        return retVal;
    }


    protected String getPathWithoutFileName(String servletPath) {
        String retVal = null;
        int lastSlash = servletPath.lastIndexOf('/');
        if (lastSlash >= 0) {
            //cut off file namee
            retVal = servletPath.substring(0, lastSlash + 1);
        }
        return retVal;
    }


    protected String getPathWithoutContext(String servletPath) {
        String retVal = null;
        int secondSlash = servletPath.indexOf('/', 1);
        if (secondSlash >= 0) {
            //cut off context
            retVal = servletPath.substring(secondSlash);
        }
        return retVal;
    }


    protected String getAbsolutePath(String path) throws IOException {
        String pathWithoutContext = SSIServletRequestUtil.getRelativePath(req);
        String prefix = getPathWithoutFileName(pathWithoutContext);
        if (prefix == null) {
            throw new IOException("Couldn't remove filename from path: "
                    + pathWithoutContext);
        }
        String fullPath = prefix + path;
        String retVal = SSIServletRequestUtil.normalize(fullPath);
        if (retVal == null) {
            throw new IOException("Normalization yielded null on path: "
                    + fullPath);
        }
        return retVal;
    }


    protected ServletContextAndPath getServletContextAndPathFromNonVirtualPath(
            String nonVirtualPath) throws IOException {
        if (nonVirtualPath.startsWith("/") || nonVirtualPath.startsWith("\\")) {
            throw new IOException("A non-virtual path can't be absolute: "
                    + nonVirtualPath);
        }
        if (nonVirtualPath.indexOf("../") >= 0) {
            throw new IOException("A non-virtual path can't contain '../' : "
                    + nonVirtualPath);
        }
        String path = getAbsolutePath(nonVirtualPath);
        ServletContextAndPath csAndP = new ServletContextAndPath(
                context, path);
        return csAndP;
    }


    protected ServletContextAndPath getServletContextAndPathFromVirtualPath(
            String virtualPath) throws IOException {

        if (!virtualPath.startsWith("/") && !virtualPath.startsWith("\\")) {
            return new ServletContextAndPath(context,
                    getAbsolutePath(virtualPath));
        } else {
            String normalized = SSIServletRequestUtil.normalize(virtualPath);
            if (isVirtualWebappRelative) {
                return new ServletContextAndPath(context, normalized);
            } else {
                ServletContext normContext = context.getContext(normalized);
                if (normContext == null) {
                    throw new IOException("Couldn't get context for path: "
                            + normalized);
                }
                //If it's the root context, then there is no context element
                // to remove,
                // ie:
                // '/file1.shtml' vs '/appName1/file1.shtml'
                if (!isRootContext(normContext)) {
                    String noContext = getPathWithoutContext(normalized);
                    if (noContext == null) {
                        throw new IOException(
                                "Couldn't remove context from path: "
                                        + normalized);
                    }
                    return new ServletContextAndPath(normContext, noContext);
                } else {
                    return new ServletContextAndPath(normContext, normalized);
                }
            }
        }
    }


    //Assumes servletContext is not-null
    //Assumes that identity comparison will be true for the same context
    //Assuming the above, getContext("/") will be non-null as long as the root
    // context is
    // accessible.
    //If it isn't, then servletContext can't be the root context anyway, hence
    // they will
    // not match.
    protected boolean isRootContext(ServletContext servletContext) {
        return servletContext == servletContext.getContext("/");
    }


    protected ServletContextAndPath getServletContextAndPath(
            String originalPath, boolean virtual) throws IOException {
        ServletContextAndPath csAndP = null;
        if (debug > 0) {
            log("SSIServletExternalResolver.getServletContextAndPath( "
                    + originalPath + ", " + virtual + ")", null);
        }
        if (virtual) {
            csAndP = getServletContextAndPathFromVirtualPath(originalPath);
        } else {
            csAndP = getServletContextAndPathFromNonVirtualPath(originalPath);
        }
        return csAndP;
    }


    protected URLConnection getURLConnection(String originalPath,
            boolean virtual) throws IOException {
        ServletContextAndPath csAndP = getServletContextAndPath(originalPath,
                virtual);
        ServletContext context = csAndP.getServletContext();
        String path = csAndP.getPath();
        URL url = context.getResource(path);
        if (url == null) {
            throw new IOException("Context did not contain resource: " + path);
        }
        URLConnection urlConnection = url.openConnection();
        return urlConnection;
    }


    public long getFileLastModified(String path, boolean virtual)
            throws IOException {
        long lastModified = 0;
        try {
            URLConnection urlConnection = getURLConnection(path, virtual);
            lastModified = urlConnection.getLastModified();
        } catch (IOException e) {
            // Ignore this. It will always fail for non-file based includes
        }
        return lastModified;
    }


    public long getFileSize(String path, boolean virtual) throws IOException {
        long fileSize = -1;
        try {
            URLConnection urlConnection = getURLConnection(path, virtual);
            fileSize = urlConnection.getContentLength();
        } catch (IOException e) {
            // Ignore this. It will always fail for non-file based includes
        }
        return fileSize;
    }


    //We are making lots of unnecessary copies of the included data here. If
    //someone ever complains that this is slow, we should connect the included
    // stream to the print writer that SSICommand uses.
    public String getFileText(String originalPath, boolean virtual)
            throws IOException {
        try {
            ServletContextAndPath csAndP = getServletContextAndPath(
                    originalPath, virtual);
            ServletContext context = csAndP.getServletContext();
            String path = csAndP.getPath();
            RequestDispatcher rd = context.getRequestDispatcher(path);
            if (rd == null) {
                throw new IOException(
                        "Couldn't get request dispatcher for path: " + path);
            }
            ByteArrayServletOutputStream basos =
                new ByteArrayServletOutputStream();
            ResponseIncludeWrapper responseIncludeWrapper =
                new ResponseIncludeWrapper(context, req, res, basos);
            rd.include(req, responseIncludeWrapper);
            //We can't assume the included servlet flushed its output
            responseIncludeWrapper.flushOutputStreamOrWriter();
            byte[] bytes = basos.toByteArray();

            //Assume platform default encoding unless otherwise specified
            String retVal;
            if (inputEncoding == null) {
                retVal = new String( bytes );
            } else {
                retVal = new String (bytes, inputEncoding);
            }

            //make an assumption that an empty response is a failure. This is
            // a problem
            // if a truly empty file
            //were included, but not sure how else to tell.
            if (retVal.equals("") && !req.getMethod().equalsIgnoreCase(
                    org.apache.coyote.http11.Constants.HEAD)) {
                throw new IOException("Couldn't find file: " + path);
            }
            return retVal;
        } catch (ServletException e) {
            throw new IOException("Couldn't include file: " + originalPath
                    + " because of ServletException: " + e.getMessage());
        }
    }

    protected class ServletContextAndPath {
        protected ServletContext servletContext;
        protected String path;


        public ServletContextAndPath(ServletContext servletContext,
                                     String path) {
            this.servletContext = servletContext;
            this.path = path;
        }


        public ServletContext getServletContext() {
            return servletContext;
        }


        public String getPath() {
            return path;
        }
    }
}