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eFaps is a framework used to map objects with or without attached files to a relational database and optional file systems (only for attaches files). Configurable access control can be provided down to object and attribute level depending on implementation and use case. Depending on requirements, events (like triggers) allow to implement business logic and to separate business logic from user interface. The framework includes integrations (e.g. webdav, full text search) and a web application as 'simple' configurable user interface. Some best practises, example web application modules (e.g. team work module) support administrators and implementers using this framework.

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/*
 * Copyright 2003 - 2011 The eFaps Team
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Revision:        $Rev: 6210 $
 * Last Changed:    $Date: 2011-02-18 16:02:56 -0500 (Fri, 18 Feb 2011) $
 * Last Changed By: $Author: [email protected] $
 */

package org.efaps.db.store;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Blob;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Map;

import javax.transaction.xa.Xid;

import org.efaps.db.Context;
import org.efaps.db.Instance;
import org.efaps.db.transaction.ConnectionResource;
import org.efaps.util.EFapsException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The class implements the {@link Resource} interface for SQL blobs. For each
 * file id a new JDBC store resource must be created.
 *
 * @author The eFaps Team
 * @version $Id: JDBCStoreResource.java 6210 2011-02-18 21:02:56Z [email protected] $
 */
public class JDBCStoreResource
    extends AbstractStoreResource
{
    /**
     * Logging instance used in this class.
     */
    private static Logger LOG = LoggerFactory.getLogger(JDBCStoreResource.class);

    /**
     * Property Name of the name of the blob in the SQL table defined with
     * property {@link #PROPERY_TABLE}.
     */
    private static final String PROPERY_BLOB  = "JDBCBlob";

    /**
     * Property Name of the name of the key (id) in the SQL table defined with
     * property {@link #PROPERY_TABLE}.
     */
    private static final String PROPERY_KEY   = "JDBCKey";

    /**
     * Property Name of the name of the SQL table.
     */
    private static final String PROPERY_TABLE = "JDBCTable";

    /**
     * The string stores the SQL table name where the blob and key is located.
     */
    private String table;

    /**
     * The string stores the name of key column to select the row in the table
     * {@link #table} (used to create the where clause).
     */
    private String keyColumn;

    /**
     * The string stores the name of the blob column in the table
     * {@link #table}.
     */
    private String blobColumn;

    /**
     * Method called to initialize this StoreResource.
     *
     * @param _instance     instance of the object this StoreResource is wanted
     *                      for
     * @param _properties   properties for this StoreResource
     * @param _compress     compress type for this StoreResource
     * @throws EFapsException on error
     * @see org.efaps.db.store.Resource#initialize(Instance, Map, Compress)
     */
    @Override()
    public void initialize(final Instance _instance,
                           final Map _properties,
                           final Compress _compress)
        throws EFapsException
    {
        super.initialize(_instance, _properties, _compress);
        this.table = _properties.get(JDBCStoreResource.PROPERY_TABLE);
        this.keyColumn = _properties.get(JDBCStoreResource.PROPERY_KEY);
        this.blobColumn = _properties.get(JDBCStoreResource.PROPERY_BLOB);
    }

    /**
     * The method writes the context (from the input stream) into a SQL blob.
     *
     * @param _in   input stream defined the content of the file
     * @param _size length of the content (or negative meaning that the length
     *              is not known; then the content gets the length of readable
     *              bytes from the input stream) return size of the created
     *              temporary file object
     * @return size of the file
     * @throws EFapsException on error
     */
    public int write(final InputStream _in,
                     final int _size)
        throws EFapsException
    {
        int size = 0;
        ConnectionResource res = null;
        try {
            res = Context.getThreadContext().getConnectionResource();

            final StringBuffer cmd = new StringBuffer().append("update ")
                .append(this.table).append(" set ")
                .append(this.blobColumn).append("=? ")
                .append("where ").append(this.keyColumn).append("=").append(getFileId());

            final PreparedStatement stmt = res.getConnection().prepareStatement(cmd.toString());
            try {
                stmt.setBinaryStream(1, _in, _size);
                stmt.execute();
            } finally {
                stmt.close();
            }
            size = _size;
            res.commit();
        } catch (final EFapsException e) {
            res.abort();
            throw e;
        } catch (final SQLException e) {
            res.abort();
            JDBCStoreResource.LOG.error("write of content failed", e);
            throw new EFapsException(JDBCStoreResource.class, "write.SQLException", e);
        }
        return size;
    }

    /**
     * Deletes the file defined in {@link #fileId}.
     */
    public void delete()
    {
    }

    /**
     * Returns for the file the input stream.
     *
     * @return input stream of the file with the content
     * @throws EFapsException on error
     */
    public InputStream read()
        throws EFapsException
    {
        StoreResourceInputStream in = null;
        ConnectionResource res = null;
        try {
            res = Context.getThreadContext().getConnectionResource();

            final Statement stmt = res.getConnection().createStatement();
            final StringBuffer cmd = new StringBuffer()
                .append("select ").append(this.blobColumn).append(" ")
                .append("from ").append(this.table).append(" ")
                .append("where ").append(this.keyColumn).append("=").append(getFileId());
            final ResultSet resultSet = stmt.executeQuery(cmd.toString());
            if (resultSet.next()) {
                if (Context.getDbType().supportsBinaryInputStream())  {
                    in = new JDBCStoreResourceInputStream(this,
                                                          res,
                                                          resultSet.getBinaryStream(1));
                } else  {
                    in = new JDBCStoreResourceInputStream(this,
                                                          res,
                                                          resultSet.getBlob(1));
                }
            }
        } catch (final IOException e) {
            JDBCStoreResource.LOG.error("read of content failed", e);
            throw new EFapsException(JDBCStoreResource.class, "read.SQLException", e);
        } catch (final SQLException e) {
            JDBCStoreResource.LOG.error("read of content failed", e);
            throw new EFapsException(JDBCStoreResource.class, "read.SQLException", e);
        } finally {
            if (in == null) {
                res.abort();
            }
        }
        return in;
    }

    /**
     * Ask the resource manager to prepare for a transaction commit of the
     * transaction specified in xid. (used for 2-phase commits).
     * @param _xid  global transaction identifier (not used, because each file
     *              with the file id gets a new VFS store resource instance)
     * @return always 0
     */
    public int prepare(final Xid _xid)
    {
        if (JDBCStoreResource.LOG.isDebugEnabled()) {
            JDBCStoreResource.LOG.debug("prepare (xid = " + _xid + ")");
        }
        return 0;
    }

    /**
     * The method is called from the transaction manager if the complete
     * transaction is completed.
Nothing is to do here, because the * commitment is done by the {@link ConnectionResource} instance. * * @param _xid global transaction identifier (not used, because each file * with the file id gets a new VFS store resource instance) * @param _onePhase true if it is a one phase commitment transaction * (not used) */ public void commit(final Xid _xid, final boolean _onePhase) { if (JDBCStoreResource.LOG.isDebugEnabled()) { JDBCStoreResource.LOG.debug("commit (xid = " + _xid + ", one phase = " + _onePhase + ")"); } } /** * If the file written in the virtual file system must be rolled back, only * the created temporary file (created from method {@link #write}) is * deleted. * * @param _xid global transaction identifier (not used, because each file * with the file id gets a new VFS store resource instance) */ public void rollback(final Xid _xid) { if (JDBCStoreResource.LOG.isDebugEnabled()) { JDBCStoreResource.LOG.debug("rollback (xid = " + _xid + ")"); } } /** * Tells the resource manager to forget about a heuristically completed * transaction branch. * * @param _xid global transaction identifier (not used, because each file * with the file id gets a new VFS store resource instance) */ public void forget(final Xid _xid) { if (JDBCStoreResource.LOG.isDebugEnabled()) { JDBCStoreResource.LOG.debug("forget (xid = " + _xid + ")"); } } /** * Obtains the current transaction timeout value set for this XAResource * instance. * * @return always 0 */ public int getTransactionTimeout() { if (JDBCStoreResource.LOG.isDebugEnabled()) { JDBCStoreResource.LOG.debug("getTransactionTimeout"); } return 0; } /** * Obtains a list of prepared transaction branches from a resource manager. * * @param _flag flag * @return always null */ public Xid[] recover(final int _flag) { if (JDBCStoreResource.LOG.isDebugEnabled()) { JDBCStoreResource.LOG.debug("recover (flag = " + _flag + ")"); } return null; } /** * Sets the current transaction timeout value for this XAResource instance. * * @param _seconds number of seconds * @return always true */ public boolean setTransactionTimeout(final int _seconds) { if (JDBCStoreResource.LOG.isDebugEnabled()) { JDBCStoreResource.LOG.debug("setTransactionTimeout (seconds = " + _seconds + ")"); } return true; } /** * @see Resource#isVFS() * @return always false */ public boolean isVFS() { return false; } /** * This class implements an InputStream to read bytes from a * {@link java.sql.Blob} if the get binary stream of the blob does not * support the available method (and returns e.g. always 0 like the Oracle * JDBC driver). * * TODO: avaible must be long! (because of max integer value!) */ private class BlobInputStream extends InputStream { /** * Stores the blob for this input stream. */ private final Blob blob; /** * The actual InputStream. */ private final InputStream in; /** * Hold the available bytes in the input stream. */ private int available; /** * @param _blob blob to be read * @throws SQLException on error with blob */ protected BlobInputStream(final Blob _blob) throws SQLException { this.blob = _blob; this.in = _blob.getBinaryStream(); this.available = (int) this.blob.length(); } /** * @see java.io.InputStream#read() * @return length of the stream * @throws IOException on error */ @Override() public int read() throws IOException { this.available--; return this.in.read(); } /** * @see java.io.InputStream#read(byte[]) * @param _bytes bytes to read * @return length of the stream * @throws IOException on error */ @Override() public int read(final byte[] _bytes) throws IOException { int length = _bytes.length; if (this.available > 0) { if (this.available < length) { length = this.available; } this.available = this.available - length; this.in.read(_bytes); } else { length = -1; } return length; } /** * @see java.io.InputStream#available() * @return true if available * @throws IOException on error */ @Override() public int available() throws IOException { return this.available; } } /** * Extdns super class. * */ private class JDBCStoreResourceInputStream extends StoreResourceInputStream { /** * The connection resource. */ private final ConnectionResource res; /** * @param _storeRe store resource itself * @param _res connection resource * @param _blob blob with the input stream * @throws SQLException on error with blob * @throws IOException on error with inputstream */ protected JDBCStoreResourceInputStream(final AbstractStoreResource _storeRe, final ConnectionResource _res, final Blob _blob) throws IOException, SQLException { super(_storeRe, Context.getDbType().supportsBlobInputStreamAvailable() ? _blob.getBinaryStream() : new BlobInputStream(_blob)); this.res = _res; } /** * @param _storeRes store resource itself * @param _res connection resource * @param _in binary input stream (from the blob) * @throws IOException on error */ protected JDBCStoreResourceInputStream(final AbstractStoreResource _storeRes, final ConnectionResource _res, final InputStream _in) throws IOException { super(_storeRes, _in); this.res = _res; } /** * @throws IOException on error */ @Override protected void beforeClose() throws IOException { super.beforeClose(); try { if (this.res.isOpened()) { this.res.commit(); } } catch (final EFapsException e) { throw new IOException("commit of connection resource not possible", e); } } } }




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