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HSQLDB example source code file (HSQLClientConnection.java)

This example HSQLDB source code file (HSQLClientConnection.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - HSQLDB tags/keywords

datainputstream, exception, hsqlclientconnection, hsqlexception, hsqlexception, io, ioexception, net, network, object, object, result, result, rowoutputbinary, sessioninterface, string, string

The HSQLDB HSQLClientConnection.java source code

/* Copyright (c) 2001-2008, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


package org.hsqldb;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;

import org.hsqldb.lib.ArrayUtil;
import org.hsqldb.rowio.RowInputBinary;
import org.hsqldb.rowio.RowOutputBinary;
import org.hsqldb.store.ValuePool;

/**
 * Base remote session proxy implementation. Uses instances of Result to
 * transmit and recieve data. This implementation utilises the updated HSQL
 * protocol.
 *
 * @author fredt@users
 * @version 1.8.0
 * @since 1.7.2
 */
public class HSQLClientConnection implements SessionInterface {

    static final int          BUFFER_SIZE = 0x1000;
    final byte[]              mainBuffer  = new byte[BUFFER_SIZE];
    private boolean           isClosed;
    private Socket            socket;
    protected OutputStream    dataOutput;
    protected DataInputStream dataInput;
    protected RowOutputBinary rowOut;
    protected RowInputBinary  rowIn;
    private Result            resultOut;
    private int               sessionID;

    //
    private boolean isReadOnly   = false;
    private boolean isAutoCommit = true;

    //
    String  host;
    int     port;
    String  path;
    String  database;
    boolean isTLS;
    int     databaseID;

    public HSQLClientConnection(String host, int port, String path,
                                String database, boolean isTLS, String user,
                                String password) throws HsqlException {

        this.host     = host;
        this.port     = port;
        this.path     = path;
        this.database = database;
        this.isTLS    = isTLS;

        initStructures();

        Result login = new Result(ResultConstants.SQLCONNECT);

        login.mainString   = user;
        login.subString    = password;
        login.subSubString = database;

        initConnection(host, port, isTLS);

        Result resultIn = execute(login);

        if (resultIn.isError()) {

/** @todo fredt - review error message */
            throw Trace.error(resultIn);
        }

        sessionID  = resultIn.sessionID;
        databaseID = resultIn.databaseID;
    }

    /**
     * resultOut is reused to trasmit all remote calls for session management.
     * Here the structure is preset for sending attributes.
     */
    private void initStructures() {

        rowOut    = new RowOutputBinary(mainBuffer);
        rowIn     = new RowInputBinary(rowOut);
        resultOut = Result.newSessionAttributesResult();

        resultOut.add(new Object[7]);
    }

    protected void initConnection(String host, int port,
                                  boolean isTLS) throws HsqlException {
        openConnection(host, port, isTLS);
    }

    protected void openConnection(String host, int port,
                                  boolean isTLS) throws HsqlException {

        try {
            socket = HsqlSocketFactory.getInstance(isTLS).createSocket(host,
                                                   port);
            dataOutput = new BufferedOutputStream(socket.getOutputStream());
            dataInput = new DataInputStream(
                new BufferedInputStream(socket.getInputStream()));
        } catch (Exception e) {

/** @todo fredt - change error to no connetion established */
            throw Trace.error(Trace.SOCKET_ERROR);
        }
    }

    protected void closeConnection() {

        try {
            if (socket != null) {
                socket.close();
            }
        } catch (Exception e) {}

        socket = null;
    }

    public synchronized Result execute(Result r) throws HsqlException {

        try {
            r.sessionID  = sessionID;
            r.databaseID = databaseID;

            write(r);

            return read();
        } catch (Throwable e) {
            throw Trace.error(Trace.CONNECTION_IS_BROKEN, e.toString());
        }
    }

    public void close() {

        if (isClosed) {
            return;
        }

        isClosed = true;

        try {
            resultOut.setResultType(ResultConstants.SQLDISCONNECT);
            execute(resultOut);
        } catch (Exception e) {}

        try {
            closeConnection();
        } catch (Exception e) {}
    }

    private Object getAttribute(int id) throws HsqlException {

        resultOut.setResultType(ResultConstants.GETSESSIONATTR);

        Result in = execute(resultOut);

        if (in.isError()) {
            throw Trace.error(in);
        }

        return in.rRoot.data[id];
    }

    private void setAttribute(Object property, int id) throws HsqlException {

        resultOut.setResultType(ResultConstants.SETSESSIONATTR);
        ArrayUtil.fillArray(resultOut.rRoot.data, null);

        resultOut.rRoot.data[id] = property;

        Result resultIn = execute(resultOut);

        if (resultIn.isError()) {
            throw Trace.error(resultIn);
        }
    }

    public boolean isReadOnly() throws HsqlException {

        Object info = getAttribute(Session.INFO_CONNECTION_READONLY);

        isReadOnly = ((Boolean) info).booleanValue();

        return isReadOnly;
    }

    public void setReadOnly(boolean mode) throws HsqlException {

        if (mode != isReadOnly) {
            setAttribute(mode ? Boolean.TRUE
                              : Boolean.FALSE, Session
                                  .INFO_CONNECTION_READONLY);

            isReadOnly = mode;
        }
    }

    public boolean isAutoCommit() throws HsqlException {

        Object info = getAttribute(SessionInterface.INFO_AUTOCOMMIT);

        isAutoCommit = ((Boolean) info).booleanValue();

        return isAutoCommit;
    }

    public void setAutoCommit(boolean mode) throws HsqlException {

        if (mode != isAutoCommit) {
            setAttribute(mode ? Boolean.TRUE
                              : Boolean.FALSE, SessionInterface
                                  .INFO_AUTOCOMMIT);

            isAutoCommit = mode;
        }
    }

    public void setIsolation(int level) throws HsqlException {
        setAttribute(ValuePool.getInt(level),
                     SessionInterface.INFO_ISOLATION);
    }

    public int getIsolation() throws HsqlException {

        Object info = getAttribute(Session.INFO_ISOLATION);

        return ((Integer) info).intValue();
    }

    public boolean isClosed() {
        return isClosed;
    }

    public Session getSession() {
        return null;
    }

    public void startPhasedTransaction() throws HsqlException {}

    public void prepareCommit() throws HsqlException {

        resultOut.setResultType(ResultConstants.SQLENDTRAN);

        resultOut.updateCount = ResultConstants.HSQLPREPARECOMMIT;

        resultOut.setMainString("");
        execute(resultOut);
    }

    public void commit() throws HsqlException {

        resultOut.setResultType(ResultConstants.SQLENDTRAN);

        resultOut.updateCount = ResultConstants.COMMIT;

        resultOut.setMainString("");
        execute(resultOut);
    }

    public void rollback() throws HsqlException {

        resultOut.setResultType(ResultConstants.SQLENDTRAN);

        resultOut.updateCount = ResultConstants.ROLLBACK;

        resultOut.setMainString("");
        execute(resultOut);
    }

    public int getId() {
        return sessionID;
    }

    /**
     * Used by pooled connections to reset the server-side session to a new
     * one. In case of failure, the connection is closed.
     *
     * When the Connection.close() method is called, a pooled connection calls
     * this method instead of HSQLClientConnection.close(). It can then
     * reuse the HSQLClientConnection object with no further initialisation.
     *
     */
    public void resetSession() throws HsqlException {

        Result login    = new Result(ResultConstants.HSQLRESETSESSION);
        Result resultIn = execute(login);

        if (resultIn.isError()) {
            isClosed = true;

            closeConnection();

            throw Trace.error(resultIn);
        }

        sessionID  = resultIn.sessionID;
        databaseID = resultIn.databaseID;
    }

    protected void write(Result r) throws IOException, HsqlException {
        Result.write(r, rowOut, dataOutput);
    }

    protected Result read() throws IOException, HsqlException {

        Result r = Result.read(rowIn, dataInput);

        rowOut.setBuffer(mainBuffer);
        rowIn.resetRow(mainBuffer.length);

        return r;
    }
}

Other HSQLDB examples (source code examples)

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