cgiservlet.java

This temp directory is used by the JVM for temporary file storage. The JVM is configured to use thi

    } //class CGIEnvironment






    /**
     * Encapsulates the knowledge of how to run a CGI script, given the
     * script's desired environment and (optionally) input/output streams
     *
     * <p>
     *
     * Exposes a <code>run</code> method used to actually invoke the
     * CGI.
     *
     * </p>
     * <p>
     *
     * The CGI environment and settings are derived from the information
     * passed to the constuctor.
     *
     * </p>
     * <p>
     *
     * The input and output streams can be set by the <code>setInput</code>
     * and <code>setResponse</code> methods, respectively.
     * </p>
     *
     * @author    Martin Dengler [[e-mail]]
     * @version   $Revision: 1.14 $, $Date: 2004/01/26 19:47:39 $
     */

    protected class CGIRunner {

        /** script/command to be executed */
        private String command = null;

        /** environment used when invoking the cgi script */
        private Hashtable env = null;

        /** working directory used when invoking the cgi script */
        private File wd = null;

        /** query parameters to be passed to the invoked script */
        private Hashtable params = null;

        /** stdin to be passed to cgi script */
        private InputStream stdin = null;

        /** response object used to set headers & get output stream */
        private HttpServletResponse response = null;

        /** boolean tracking whether this object has enough info to run() */
        private boolean readyToRun = false;




        /**
         *  Creates a CGIRunner and initializes its environment, working
         *  directory, and query parameters.
         *  <BR>
         *  Input/output streams (optional) are set using the
         *  <code>setInput</code> and <code>setResponse</code> methods,
         *  respectively.
         *
         * @param  command  string full path to command to be executed
         * @param  env      Hashtable with the desired script environment
         * @param  wd       File with the script's desired working directory
         * @param  params   Hashtable with the script's query parameters
         *
         * @param  res       HttpServletResponse object for setting headers
         *                   based on CGI script output
         *
         */
        protected CGIRunner(String command, Hashtable env, File wd,
                            Hashtable params) {
            this.command = command;
            this.env = env;
            this.wd = wd;
            this.params = params;
            updateReadyStatus();
        }



        /**
         * Checks & sets ready status
         */
        protected void updateReadyStatus() {
            if (command != null
                && env != null
                && wd != null
                && params != null
                && response != null) {
                readyToRun = true;
            } else {
                readyToRun = false;
            }
        }



        /**
         * Gets ready status
         *
         * @return   false if not ready (<code>run</code> will throw
         *           an exception), true if ready
         */
        protected boolean isReady() {
            return readyToRun;
        }



        /**
         * Sets HttpServletResponse object used to set headers and send
         * output to
         *
         * @param  response   HttpServletResponse to be used
         *
         */
        protected void setResponse(HttpServletResponse response) {
            this.response = response;
            updateReadyStatus();
        }



        /**
         * Sets standard input to be passed on to the invoked cgi script
         *
         * @param  stdin   InputStream to be used
         *
         */
        protected void setInput(InputStream stdin) {
            this.stdin = stdin;
            updateReadyStatus();
        }



        /**
         * Converts a Hashtable to a String array by converting each
         * key/value pair in the Hashtable to a String in the form
         * "key=value" (hashkey + "=" + hash.get(hashkey).toString())
         *
         * @param  h   Hashtable to convert
         *
         * @return     converted string array
         *
         * @exception  NullPointerException   if a hash key has a null value
         *
         */
        protected String[] hashToStringArray(Hashtable h)
            throws NullPointerException {
            Vector v = new Vector();
            Enumeration e = h.keys();
            while (e.hasMoreElements()) {
                String k = e.nextElement().toString();
                v.add(k + "=" + h.get(k));
            }
            String[] strArr = new String[v.size()];
            v.copyInto(strArr);
            return strArr;
        }



        /**
         * Executes a CGI script with the desired environment, current working
         * directory, and input/output streams
         *
         * <p>
         * This implements the following CGI specification recommedations:
         * <UL>
         * <LI> Servers SHOULD provide the "<code>query</code>" component of
         *      the script-URI as command-line arguments to scripts if it
         *      does not contain any unencoded "=" characters and the
         *      command-line arguments can be generated in an unambiguous
         *      manner.
         * <LI> Servers SHOULD set the AUTH_TYPE metavariable to the value
         *      of the "<code>auth-scheme</code>" token of the
         *      "<code>Authorization</code>" if it was supplied as part of the
         *      request header.  See <code>getCGIEnvironment</code> method.
         * <LI> Where applicable, servers SHOULD set the current working
         *      directory to the directory in which the script is located
         *      before invoking it.
         * <LI> Server implementations SHOULD define their behavior for the
         *      following cases:
         *     <ul>
         *     <LI> <u>Allowed characters in pathInfo</u>:  This implementation
         *             does not allow ASCII NUL nor any character which cannot
         *             be URL-encoded according to internet standards;
         *     <LI> <u>Allowed characters in path segments</u>: This
         *             implementation does not allow non-terminal NULL
         *             segments in the the path -- IOExceptions may be thrown;
         *     <LI> <u>"<code>.</code>" and "<code>..</code>" path
         *             segments</u>:
         *             This implementation does not allow "<code>.</code>" and
         *             "<code>..</code>" in the the path, and such characters
         *             will result in an IOException being thrown;
         *     <LI> <u>Implementation limitations</u>: This implementation
         *             does not impose any limitations except as documented
         *             above.  This implementation may be limited by the
         *             servlet container used to house this implementation.
         *             In particular, all the primary CGI variable values
         *             are derived either directly or indirectly from the
         *             container's implementation of the Servlet API methods.
         *     </ul>
         * </UL>
         * </p>
         *
         * @exception IOException if problems during reading/writing occur
         *
         * @see    java.lang.Runtime#exec(String command, String[] envp,
         *                                File dir)
         */
        protected void run() throws IOException {

            /*
             * REMIND:  this method feels too big; should it be re-written?
             */

            if (!isReady()) {
                throw new IOException(this.getClass().getName()
                                      + ": not ready to run.");
            }

            if (debug >= 1 ) {
                log("runCGI(envp=[" + env + "], command=" + command + ")");
            }

            if ((command.indexOf(File.separator + "." + File.separator) >= 0)
                || (command.indexOf(File.separator + "..") >= 0)
                || (command.indexOf(".." + File.separator) >= 0)) {
                throw new IOException(this.getClass().getName()
                                      + "Illegal Character in CGI command "
                                      + "path ('.' or '..') detected.  Not "
                                      + "running CGI [" + command + "].");
            }

            /* original content/structure of this section taken from
             * http://developer.java.sun.com/developer/
             *                               bugParade/bugs/4216884.html
             * with major modifications by Martin Dengler
             */
            Runtime rt = null;
            BufferedReader commandsStdOut = null;
            BufferedReader commandsStdErr = null;
            BufferedOutputStream commandsStdIn = null;
            Process proc = null;
            int bufRead = -1;

            //create query arguments
            Enumeration paramNames = params.keys();
            StringBuffer cmdAndArgs = new StringBuffer();
            if (command.indexOf(" ") < 0) {
                cmdAndArgs.append(command);
            } else {
                // Spaces used as delimiter, so need to use quotes
                cmdAndArgs.append("\"");
                cmdAndArgs.append(command);
                cmdAndArgs.append("\"");
            }
            
            if (paramNames != null && paramNames.hasMoreElements()) {
                cmdAndArgs.append(" ");
                while (paramNames.hasMoreElements()) {
                    String k = (String) paramNames.nextElement();
                    String v = params.get(k).toString();
                    if ((k.indexOf("=") < 0) && (v.indexOf("=") < 0)) {
                        StringBuffer arg = new StringBuffer(k);
                        arg.append("=");
                        v = java.net.URLEncoder.encode(v);
                        arg.append(v);
                        if (arg.toString().indexOf(" ") < 0) {
                            cmdAndArgs.append(arg);
                        } else {
                            // Spaces used as delimiter, so need to use quotes
                            cmdAndArgs.append("\"");
                            cmdAndArgs.append(arg);
                            cmdAndArgs.append("\"");
                        }
                        cmdAndArgs.append(" ");
                    }
                }
            }

            /*String postIn = getPostInput(params);
            int contentLength = (postIn.length()
                    + System.getProperty("line.separator").length());
            if ("POST".equals(env.get("REQUEST_METHOD"))) {
                env.put("CONTENT_LENGTH", new Integer(contentLength));
            }*/

        //if (command.endsWith(".pl") || command.endsWith(".cgi")) {
            StringBuffer command = new StringBuffer(cgiExecutable);
            command.append(" ");
            command.append(cmdAndArgs.toString());
            cmdAndArgs = command;
        //}

            rt = Runtime.getRuntime();
            proc = rt.exec(cmdAndArgs.toString(), hashToStringArray(env), wd);

            /*
             * provide input to cgi
             * First  -- parameters
             * Second -- any remaining input
             */
            /*commandsStdIn = new BufferedOutputStream(proc.getOutputStream());
            if (debug >= 2 ) {
                log("runCGI stdin=[" + stdin + "], qs="
                    + env.get("QUERY_STRING"));
            }
            if ("POST".equals(env.get("REQUEST_METHOD"))) {
                if (debug >= 2) {
                    log("runCGI: writing ---------------\n");
                    log(postIn);
                    log("runCGI: new content_length=" + contentLength
                        + "---------------\n");
                }
                commandsStdIn.write(postIn.getBytes());
            }
            if (stdin != null) {
                //REMIND: document this
                /* assume if nothing is available after a time, that nothing is
                 * coming...
                 */
                /*if (stdin.available() <= 0) {
                    if (debug >= 2 ) {
                        log("runCGI stdin is NOT available ["
                            + stdin.available() + "]");
                    }
                    try {
                        Thread.currentThread().sleep(iClientInputTimeout);
                    } catch (InterruptedException ignored) {
                    }