dbpersistencemanager.java

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        Statement stat=null;
        try {
            conn=this.getConnection();
            stat=conn.createStatement();
            stat.executeQuery("delete from replhashmap");
        }
        catch(Throwable t) {
            //trace here
            throw new CannotRemoveException(t, " delete all query failed with existing database");
        }

        //finally
        try {
            stat.close();
            this.closeConnection(conn);
        }
        catch(Throwable t) {
            conn=null;
            stat=null;
        }
    }


    /**
     * Shutting down the database cleanly
     */
    public void shutDown() {
        // non-trivial problem, more research required
        // no-op for now..
    }



    /**
     * The private interfaces are used specifically to this manager
     */

    /**
     * Used to enter a completely new row in to the current table
     * @param Serializable; key
     * @param Serializable; value
     * @exception CannotPersistException;
     */
    private void addNewEntry(Serializable key, Serializable val) throws CannotPersistException, CannotConnectException {
        Connection conn=getConnection();
        try {
            PreparedStatement prepStat=conn.prepareStatement(insertStat);
            prepStat.setString(1, key.toString());
            byte[] keyBytes=getBytes(key);
            byte[] valBytes=getBytes(val);
            //InputStream keyStream = getBinaryInputStream(key);
            //InputStream valStream = getBinaryInputStream(val);
            prepStat.setBytes(2, keyBytes);
            prepStat.setBytes(3, valBytes);
            //prepStat.setBinaryStream(keyStream);
            //prepStat.setBinaryStream(valStream);
            prepStat.executeQuery();
            conn.commit();
            log.error(" executing insert " + insertStat);
        }
        catch(Throwable t) {
            //conn.rollback();
            t.printStackTrace();
            //trace here
            throw new CannotPersistException(t, "error adding new entry using creating Db connection and schema");
        }
    }// end of addentry..


    /**
     * Gets a binaryinputstream from a serialized object
     * @param Serializable;
     * @return BinaryInputStream;
     * @exception Exception;
     */
    private java.io.InputStream getBinaryInputStream(Serializable ser) throws Exception {
        ByteArrayOutputStream stream=new ByteArrayOutputStream();
        ObjectOutputStream keyoos=new ObjectOutputStream(stream);
        keyoos.writeObject(ser);
        ByteArrayInputStream pipe=new ByteArrayInputStream(stream.toByteArray());
        return pipe;
    }// end of stream conversion


    /**
     * Gets a serializable back from a InputStream
     * @param InputStream;
     * @return Serializable;
     * @exception Exception;
     */
    private Serializable getSerializable(java.io.InputStream stream) throws Exception {
        ObjectInputStream ooStr=new ObjectInputStream(stream);
        Serializable tmp=(Serializable) ooStr.readObject();
        return tmp;
    }


    /**
     * Used to enter a completely new row in to the current table
     * @param Serializable; key
     * @param Serializable; value
     * @exception CannotPersistException;
     */
    private void addNewEntryGen(Serializable key, Serializable val) throws CannotPersistException, CannotConnectException {
        Connection conn=getConnection();
        try {
            PreparedStatement prepStat=conn.prepareStatement(insertStat);
            prepStat.setString(1, key.toString());
            prepStat.setBytes(2, getBytes(key));
            prepStat.setBytes(3, getBytes(val));
            prepStat.executeUpdate();
        }
        catch(Throwable t) {
            //trace here
            throw new CannotPersistException(t, "error adding new entry using creating Db connection and schema");
        }
    }// end of entering new row gen

    /**
     * Used to enter a completely new row in to the current table
     * @param Serializable; key
     * @param Serializable; value
     * @exception CannotPersistException;
     */
    private void addNewEntryOra(Serializable key, Serializable val) throws CannotPersistException, CannotConnectException {
        Connection conn=getConnection();
        try {
            PreparedStatement prepStat=conn.prepareStatement(insertStat);
            prepStat.setString(1, key.toString());
            InputStream keyBin=getBinaryInputStream(key);
            InputStream keyVal=getBinaryInputStream(val);
            byte[] keyBytes=getBytes(key);
            byte[] valBytes=getBytes(val);
            prepStat.setBytes(2, keyBytes);
            prepStat.setBytes(3, valBytes);
            prepStat.executeBatch();
        }
        catch(Throwable t) {
            //trace here
            throw new CannotPersistException(t, "error adding new entry using creating Db connection and schema");
        }
    }// end of entering new row ora


    /**
     * Cache checking
     * @param java.io.Serializable
     * @return boolean;
     */
    private boolean entryExists(Serializable key) {
        return list.contains(key.toString());
    }


    /**
     * Conversion helper
     * @param Serializable;
     * @return byte[];
     */
    private byte[] getBytes(Serializable ser) throws Exception {
        ByteArrayOutputStream stream=new ByteArrayOutputStream();
        ObjectOutputStream keyoos=new ObjectOutputStream(stream);
        keyoos.writeObject(ser);
        byte[] keyBytes=stream.toByteArray();
        return keyBytes;
    }// end of getBytes




    /**
     * ALL IMPL below is for INIT purposes
     */

    /**
     * This method will be invoked by defauly by each persistence
     * manager to read from a default location or one provided by
     * the caller.
     * @return void;
     * @exception Exception;
     */
    private void readProps(String filePath) throws Exception {
        FileInputStream _stream=new FileInputStream(filePath);
        props=new Properties();
        props.load(_stream);

        // using properties to set most used variables
        driverName=props.getProperty("jdbc.Driver");
        connStr=props.getProperty("jdbc.Conn").trim();
        userName=props.getProperty("jdbc.User").trim();
        userPass=props.getProperty("jdbc.Pass").trim();
        createTable=props.getProperty("jdbc.table").trim();
    }


    /**
     * Duplicate reader using stream instead of dile
     * @param InputStream;
     * @exception Exception;
     */
    private void readProps(InputStream input) throws Exception {
        props=new Properties();
        props.load(input);

        // using properties to set most used variables
        driverName=props.getProperty("jdbc.Driver");
        connStr=props.getProperty("jdbc.Conn");
        userName=props.getProperty("jdbc.User");
        userPass=props.getProperty("jdbc.Pass");
        createTable=props.getProperty("jdbc.table");
    }


    /**
     * Loads the driver using the driver class name. Drivers can be simply
     * loaded by loading the class or by registering specifically using the
     * JDBC DriverManager
     * @return void;
     * @exception Exception;
     */
    private void loadDriver() throws Exception {
        // driver classes when loaded load the driver into VM
        Class.forName(driverName);
    }


    /**
     * Once the driver is loaded, the DB is ready to be connected. This
     * method provides a handle to connect to the DB.
     * @return Connection;
     * @exception CannotConnectException;
     */
    private Connection getConnection() throws CannotConnectException {
        try {
            connStr=connStr.trim();
            Connection conn=DriverManager.getConnection(connStr, userName, userPass);
            if(log.isInfoEnabled()) log.info("userName=" + userName +
                                             ", userPass=" + userPass + ", connStr=" + connStr);
            return conn;
        }
        catch(Throwable t) {
            t.printStackTrace();
            //trace here
            throw new CannotConnectException(t, "Error in creating connection using provided properties ");
        }
    }// end of get conn..


    /**
     * Method is used for closing created connection.
     * Pooling is not implemented currently, but will be made available
     * as soon as this manager uses large number of transactions
     * @param Connection
     */
    private void closeConnection(Connection conn) {
        try {
            if(conn != null) {
                conn.close();
                conn=null;
            }
        }
        catch(Throwable t) {
            //trace here
            conn=null;
        }
    }// end of closeConn


    /**
     * Used to create table provided the DB instance
     * @exception CannotCreateSchemaException;
     * @exception CannotConnectException;
     */
    private void createDBTables() throws CannotCreateSchemaException, CannotConnectException {
        Connection conn=this.getConnection();
        Statement stat=null;
        try {
            stat=conn.createStatement();
        }
        catch(Exception e) {
            //trace here..
            e.printStackTrace();
            throw new CannotConnectException(e, "there was an error in creating statements for persisting data using created connection");
        }
        try {
            ResultSet set=stat.executeQuery("select * from replhashmap");
        }
        catch(Throwable t) {
            t.printStackTrace();
            //use connection to create new statement
            addSchemaToDB(conn);
        }// end of out throwable..
    }// end of method..


    /**
     * used to create required table within the DB
     * @param Connection;
     * @exception CannotCreateSchema;
     */
    private void addSchemaToDB(Connection conn) throws CannotCreateSchemaException {
        Statement stat=null;
        Statement stat2=null;
        try {

            stat=conn.createStatement();
            log.error(" executing query for oracle " + createTable);
            stat.executeQuery(createTable);
        }
        catch(Throwable t) {
            t.printStackTrace();
            // trace here
            throw new CannotCreateSchemaException(t, "error was using schema with blobs");
        }// end of catch

                // clean up is required after init
        finally {
            try {
                if(stat != null) stat.close();
                this.closeConnection(conn);
            }
            catch(Throwable t3) {
            }
        }// end of finally..
    }// end of gen schema..

    private Properties props=null;
    private String driverName=null;
    private String userName=null;
    private String userPass=null;
    private String connStr=null;
    private String createTable=null;
    private final boolean oracleDB=false;
    private Vector list=null;


    private static final String tabName="replhashmap";
    private static final String insertStat="insert into replhashmap(key, keyBin, valBin) values  (?, ?, ?)";
    private static final String updateStat="update replhashmap set keyBin = ?, valBin = ? where key like ?";
    private static final String removeStat=" delete from replhashmap where key like ?";
    private static final String createTableGen=" create table replhashmap(key varchar, keyBin varbinary, valBin varbinary)";
    private static final String createTableOra=" create table replhashmap ( key varchar2(100), keyBin blob, valBin blob)";
}