* The remote applet / application should * use the normal JDBC interfaces to connect to the URL of this servlet. An * example URL is: *
* jdbc:hsqldb:http://myhost.com:8080/servlet/org.hsqldb.server.Servlet ** The database path/name is taken from the servlet engine property: *
* hsqldb.server.database **
* If the database is deployed in the WEB-INF directory of the servlet container, * the property: *
* hsqldb.server.use_web-inf_path ** should be set "true" in the web.xml file of the servlet container. * In this case, the database path should begin with a "/". * * JDBC connections via the HTTP protocol are persistent * in the JDBC sense. The JDBC Connection that is established can support * transactions spanning several Statement calls and real PreparedStatement * calls are supported. This class has been rewritten to support the new * features.
* (fredt@users)
* * Extensively rewritten for HSQLDB. * * @author Thomas Mueller (Hypersonic SQL Group) * @author Fred Toussi (fredt@users dot sourceforge.net) * @version 2.2.9 * @since Hypersonic SQL */ public class Servlet extends javax.servlet.http.HttpServlet { private static final int BUFFER_SIZE = 256; private String dbType; private String dbPath; private String errorStr; private RowOutputBinary rowOut; private RowInputBinary rowIn; private int iQueries; public void init(ServletConfig config) { try { super.init(config); rowOut = new RowOutputBinary(BUFFER_SIZE, 1); rowIn = new RowInputBinary(rowOut); } catch (ServletException e) { log(e.toString()); } String dbStr = getInitParameter("hsqldb.server.database"); if (dbStr == null) { dbStr = "."; } // begin WEB-INF patch */ String useWebInfStr = getInitParameter("hsqldb.server.use_web-inf_path"); if (!dbStr.equals(".") && "true".equalsIgnoreCase(useWebInfStr)) { dbStr = getServletContext().getRealPath("/") + "WEB-INF/" + dbStr; } // end WEB-INF patch HsqlProperties dbURL = DatabaseURL.parseURL(dbStr, false, false); log("Database filename = " + dbStr); if (dbURL == null) { errorStr = "Bad Database name"; } else { dbPath = dbURL.getProperty("database"); dbType = dbURL.getProperty("connection_type"); try { DatabaseManager.getDatabase(dbType, dbPath, dbURL); } catch (HsqlException e) { errorStr = e.getMessage(); } } if (errorStr == null) { log("Initialization completed."); } else { log("Database could not be initialised."); log(errorStr); } } private static long lModified = 0; protected long getLastModified(HttpServletRequest req) { // this is made so that the cache of the http server is not used // maybe there is some other way return lModified++; } public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { String query = request.getQueryString(); if ((query == null) || (query.length() == 0)) { response.setContentType("text/html"); // fredt@users 20020130 - patch 1.7.0 by fredt // to avoid caching on the browser response.setHeader("Pragma", "no-cache"); PrintWriter out = response.getWriter(); out.println( "
"); if (errorStr == null) { out.println("The database is also running.
"); out.println("Database name: " + dbType + dbPath + "
"); out.println("Queries processed: " + iQueries + "
"); } else { out.println("
"); out.println(errorStr); } out.println(""); } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { synchronized (this) { DataInputStream inStream = null; DataOutputStream dataOut = null; try { // fredt@users - the servlet container, Resin does not return all // the bytes with one call to input.read(b,0,len) when len > 8192 // bytes, the loop in the Result.read() method handles this inStream = new DataInputStream(request.getInputStream()); int databaseID = inStream.readInt(); long sessionID = inStream.readLong(); int mode = inStream.readByte(); Session session = DatabaseManager.getSession(databaseID, sessionID); Result resultIn = Result.newResult(session, mode, inStream, rowIn); resultIn.setDatabaseId(databaseID); resultIn.setSessionId(sessionID); Result resultOut; int type = resultIn.getType(); if (type == ResultConstants.CONNECT) { try { session = DatabaseManager.newSession( dbType, dbPath, resultIn.getMainString(), resultIn.getSubString(), new HsqlProperties(), resultIn.getZoneString(), resultIn.getUpdateCount()); resultIn.readAdditionalResults(null, inStream, rowIn); resultOut = Result.newConnectionAcknowledgeResponse( session.getDatabase(), session.getId(), session.getDatabase().getDatabaseID()); } catch (HsqlException e) { resultOut = Result.newErrorResult(e); } } else if (type == ResultConstants.DISCONNECT || type == ResultConstants.RESETSESSION) { // Upon DISCONNECT 6 bytes are read by the ClientConnectionHTTP": mode (1 byte), a length (int), and an 'additional results (1 byte) response.setHeader("Cache-Control", "no-cache"); // DB-traffic should not be cached by proxy's response.setContentType("application/octet-stream"); response.setContentLength(6); // Only acquire output-stream after headers are set dataOut = new DataOutputStream(response.getOutputStream()); dataOut.writeByte(ResultConstants.DISCONNECT); // Mode dataOut.writeInt(4); //Length Int of first result is always read! Minvalue is 4: It is the number of bytes of the current result (it includes the length of this Int itself) dataOut.writeByte(ResultConstants.NONE); // No Additional results dataOut.close(); return; } else { int dbId = resultIn.getDatabaseId(); long sessionId = resultIn.getSessionId(); session = DatabaseManager.getSession(dbId, sessionId); resultIn.readLobResults(session, inStream, rowIn); resultOut = session.execute(resultIn); } HsqlByteArrayOutputStream memStream = new HsqlByteArrayOutputStream(); DataOutputStream tempOutput = new DataOutputStream(memStream); resultOut.write(session, tempOutput, rowOut); response.setHeader("Cache-Control", "no-cache"); // DB-traffic should not be cached by proxy's response.setContentType("application/octet-stream"); response.setContentLength(memStream.size()); // Only acquire output-stream after headers are set dataOut = new DataOutputStream(response.getOutputStream()); memStream.writeTo(dataOut); iQueries++; } catch (HsqlException e) {} finally { if (dataOut != null) { dataOut.close(); } if (inStream != null) { inStream.close(); } } } // Trace.printSystemOut("Queries processed: "+iQueries+" \n"); } }