webserverconnection.java

hsqldb是100％java实现的数据库,是一个开放源代码的JAVA数据库 l 具有标准的SQL语法和JAVA接口 l HSQLDB可以自由使用和分发 l 非常简洁和快速的

            // read and parse the Content-Length line
            int count  = InOutUtil.readLine(inStream, rowOut);
            int offset = rowOut.size() - count;

            // get buffer always after reading into rowOut, else old buffer may
            // be returned
            byte[] byteArray = rowOut.getBuffer();

            if (!ArrayUtil.containsAt(byteArray, offset, BYTES_CONTENT)) {
                throw new Exception();
            }

            count  -= BYTES_CONTENT.length;
            offset += BYTES_CONTENT.length;

            // omit the last two characters
            String lenStr = new String(byteArray, offset, count - 2);
            int    length = Integer.parseInt(lenStr);

            InOutUtil.readLine(inStream, rowOut);
        } catch (Exception e) {
            processError(HttpURLConnection.HTTP_BAD_REQUEST);

            return;
        }

        processQuery(inStream);
    }

    /**
     * Processes a database query in HSQL protocol that has been
     * tunneled over HTTP protocol.
     *
     * @param inStream the incoming byte stream representing the HSQL protocol
     *      database query
     */
    void processQuery(InputStream inStream) {

        try {
            Result resultIn = Result.read(rowIn,
                                          new DataInputStream(inStream));

            //
            Result resultOut;

            if (resultIn.mode == ResultConstants.SQLCONNECT) {
                try {
                    int dbID = server.getDBID(resultIn.subSubString);
                    Session session = DatabaseManager.newSession(dbID,
                        resultIn.getMainString(), resultIn.getSubString());

                    resultOut = new Result(ResultConstants.UPDATECOUNT);
                    resultOut.databaseID = dbID;
                    resultOut.sessionID  = session.getId();
                } catch (HsqlException e) {
                    resultOut = new Result(e, null);
                } catch (RuntimeException e) {
                    resultOut = new Result(e, null);
                }
            } else {
                int dbID = resultIn.databaseID;
                Session session = DatabaseManager.getSession(dbID,
                    resultIn.sessionID);

                resultOut =
                    session == null
                    ? new Result(Trace.error(Trace.DATABASE_NOT_EXISTS), null)
                    : session.execute(resultIn);
            }

//
            rowOut.reset();
            resultOut.write(rowOut);

            OutputStream outStream = socket.getOutputStream();
            String header = getHead(HEADER_OK, false,
                                    "application/octet-stream",
                                    rowOut.size());

            outStream.write(header.getBytes(ENCODING));
            outStream.write(rowOut.getOutputStream().getBuffer(), 0,
                            rowOut.getOutputStream().size());
            outStream.flush();
            outStream.close();
        } catch (Exception e) {
            server.printStackTrace(e);
        }
    }

    /**
     *  Processes an HTTP GET request
     *
     * @param  name the name of the content to get
     * @param  send whether to send the content as well, or just the header
     */
    private void processGet(String name, boolean send) {

        try {
            String       hdr;
            OutputStream os;
            InputStream  is;
            int          b;

            if (name.endsWith("/")) {
                name = name + server.getDefaultWebPage();
            }

            // traversing up the directory structure is forbidden.
            if (name.indexOf("..") != -1) {
                processError(HttpURLConnection.HTTP_FORBIDDEN);

                return;
            }

            name = server.getWebRoot() + name;

            if (File.separatorChar != '/') {
                name = name.replace('/', File.separatorChar);
            }

            is = null;

            server.printWithThread("GET " + name);

            try {
                File file = new File(name);

                is = new DataInputStream(new FileInputStream(file));
                hdr = getHead(HEADER_OK, true, getMimeTypeString(name),
                              (int) file.length());
            } catch (IOException e) {
                processError(HttpURLConnection.HTTP_NOT_FOUND);

                if (is != null) {
                    is.close();
                }

                return;
            }

            os = new BufferedOutputStream(socket.getOutputStream());

            os.write(hdr.getBytes(ENCODING));

            if (send) {
                while ((b = is.read()) != -1) {
                    os.write(b);
                }
            }

            os.flush();
            os.close();
            is.close();
        } catch (Exception e) {
            server.printError("processGet: " + e.toString());
            server.printStackTrace(e);
        }
    }

    /**
     * Retrieves an HTTP protocol header given the supplied arguments.
     *
     * @param responseCodeString the HTTP response code
     * @param addInfo true if additional header info is to be added
     * @param mimeType the Content-Type field value
     * @param length the Content-Length field value
     * @return an HTTP protocol header
     */
    String getHead(String responseCodeString, boolean addInfo,
                   String mimeType, int length) {

        StringBuffer sb = new StringBuffer(128);

        sb.append(responseCodeString).append("\r\n");

        if (addInfo) {
            sb.append("Allow: GET, HEAD, POST\nMIME-Version: 1.0\r\n");
            sb.append("Server: ").append(
                HsqlDatabaseProperties.PRODUCT_NAME).append("\r\n");
        }

        if (mimeType != null) {
            sb.append("Content-Type: ").append(mimeType).append("\r\n");
            sb.append("Content-Length: ").append(length).append("\r\n");
        }

        sb.append("\r\n");

        return sb.toString();
    }

    /**
     *  Processess an HTTP error condition, sending an error response to
     *  the client.
     *
     * @param code the error condition code
     */
    private void processError(int code) {

        String msg;

        server.printWithThread("processError " + code);

        switch (code) {

            case HttpURLConnection.HTTP_BAD_REQUEST :
                msg = getHead(HEADER_BAD_REQUEST, false, null, 0);
                msg += BundleHandler.getString(WebServer.webBundleHandle,
                                               "BAD_REQUEST");
                break;

            case HttpURLConnection.HTTP_FORBIDDEN :
                msg = getHead(HEADER_FORBIDDEN, false, null, 0);
                msg += BundleHandler.getString(WebServer.webBundleHandle,
                                               "FORBIDDEN");
                break;

            case HttpURLConnection.HTTP_NOT_FOUND :
            default :
                msg = getHead(HEADER_NOT_FOUND, false, null, 0);
                msg += BundleHandler.getString(WebServer.webBundleHandle,
                                               "NOT_FOUND");
                break;
        }

        try {
            OutputStream os =
                new BufferedOutputStream(socket.getOutputStream());

            os.write(msg.getBytes(ENCODING));
            os.flush();
            os.close();
        } catch (Exception e) {
            server.printError("processError: " + e.toString());
            server.printStackTrace(e);
        }
    }

    /**
     * Retrieves the thread name to be used  when
     * this object is the Runnable object of a Thread.
     *
     * @return the thread name to be used  when
     *      this object is the Runnable object of a Thread.
     */
    String getConnectionThreadName() {
        return "HSQLDB HTTP Connection @" + Integer.toString(hashCode(), 16);
    }
}