oraclefilesystem.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
package org.apache.jackrabbit.core.fs.db;

import org.apache.jackrabbit.util.Text;
import org.apache.jackrabbit.util.TransientFileFactory;
import org.apache.jackrabbit.core.fs.FileSystemException;
import org.apache.jackrabbit.core.fs.FileSystemPathUtil;
import org.apache.jackrabbit.core.fs.RandomAccessOutputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.jcr.RepositoryException;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.Blob;
import java.sql.Connection;
import java.io.InputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.IOException;
import java.io.File;
import java.io.FilterOutputStream;
import java.io.FileOutputStream;
import java.io.FileInputStream;
import java.io.RandomAccessFile;
import java.lang.reflect.Method;

/**
 * <code>OracleFileSystem</code> is a JDBC-based <code>FileSystem</code>
 * implementation for Jackrabbit that persists file system entries in an
 * Oracle database.
 * <p/>
 * It is configured through the following properties:
 * <ul>
 * <li><code>driver</code>: the FQN name of the JDBC driver class
 * (default: <code>"oracle.jdbc.OracleDriver"</code>)</li>
 * <li><code>schema</code>: type of schema to be used
 * (default: <code>"oracle"</code>)</li>
 * <li><code>url</code>: the database url (e.g.
 * <code>"jdbc:oracle:thin:@[host]:[port]:[sid]"</code>)</li>
 * <li><code>user</code>: the database user</li>
 * <li><code>password</code>: the user's password</li>
 * <li><code>schemaObjectPrefix</code>: prefix to be prepended to schema objects</li>
 * </ul>
 * See also {@link DbFileSystem}.
 * <p/>
 * The following is a fragment from a sample configuration:
 * <pre>
 *   &lt;FileSystem class="org.apache.jackrabbit.core.fs.db.OracleFileSystem"&gt;
 *       &lt;param name="url" value="jdbc:oracle:thin:@127.0.0.1:1521:orcl"/&gt;
 *       &lt;param name="user" value="scott"/&gt;
 *       &lt;param name="password" value="tiger"/&gt;
 *       &lt;param name="schemaObjectPrefix" value="rep_"/&gt;
 *  &lt;/FileSystem&gt;
 * </pre>
 */
public class OracleFileSystem extends DbFileSystem {

    /**
     * Logger instance
     */
    private static Logger log = LoggerFactory.getLogger(OracleFileSystem.class);

    private Class blobClass;
    private Integer DURATION_SESSION_CONSTANT;
    private Integer MODE_READWRITE_CONSTANT;

    /**
     * Creates a new <code>OracleFileSystem</code> instance.
     */
    public OracleFileSystem() {
        // preset some attributes to reasonable defaults
        schema = "oracle";
        driver = "oracle.jdbc.OracleDriver";
        schemaObjectPrefix = "";
        user = "";
        password = "";
        initialized = false;
    }

    //-----------------------------------------< DatabaseFileSystem overrides >
    /**
     * {@inheritDoc}
     * <p/>
     * Retrieve the <code>oracle.sql.BLOB</code> class via reflection, and
     * initialize the values for the <code>DURATION_SESSION</code> and
     * <code>MODE_READWRITE</code> constants defined there.
     * @see oracle.sql.BLOB#DURATION_SESSION
     * @see oracle.sql.BLOB#MODE_READWRITE
     */
    public void init() throws FileSystemException {
        super.init();

        // initialize oracle.sql.BLOB class & constants

        // use the Connection object for using the exact same
        // class loader that the Oracle driver was loaded with
        try {
            blobClass = con.getClass().getClassLoader().loadClass("oracle.sql.BLOB");
            DURATION_SESSION_CONSTANT =
                    new Integer(blobClass.getField("DURATION_SESSION").getInt(null));
            MODE_READWRITE_CONSTANT =
                    new Integer(blobClass.getField("MODE_READWRITE").getInt(null));
        } catch (Exception e) {
            String msg = "failed to load/introspect oracle.sql.BLOB";
            log.error(msg, e);
            throw new FileSystemException(msg, e);
        }
    }

    /**
     * {@inheritDoc}
     * <p/>
     * Overridden in order to support multiple oracle schemas. Note that
     * schema names in Oracle correspond to the username of the connection.
     * See http://issues.apache.org/jira/browse/JCR-582
     *
     * @throws Exception if an error occurs
     */
    protected void checkSchema() throws Exception {
        DatabaseMetaData metaData = con.getMetaData();
        String tableName = schemaObjectPrefix + "FSENTRY";
        if (metaData.storesLowerCaseIdentifiers()) {
            tableName = tableName.toLowerCase();
        } else if (metaData.storesUpperCaseIdentifiers()) {
            tableName = tableName.toUpperCase();
        }
        String userName = metaData.getUserName();

        ResultSet rs = metaData.getTables(null, userName, tableName, null);
        boolean schemaExists;
        try {
            schemaExists = rs.next();
        } finally {
            rs.close();
        }

        if (!schemaExists) {
            // read ddl from resources
            InputStream in = OracleFileSystem.class.getResourceAsStream(schema + ".ddl");
            if (in == null) {
                String msg = "Configuration error: unknown schema '" + schema + "'";
                log.debug(msg);
                throw new RepositoryException(msg);
            }
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            Statement stmt = con.createStatement();
            try {
                String sql = reader.readLine();
                while (sql != null) {
                    // Skip comments and empty lines
                    if (!sql.startsWith("#") && sql.length() > 0) {
                        // replace prefix variable
                        sql = Text.replace(sql, SCHEMA_OBJECT_PREFIX_VARIABLE, schemaObjectPrefix);
                        // execute sql stmt
                        stmt.executeUpdate(sql);
                    }
                    // read next sql stmt
                    sql = reader.readLine();
                }
            } finally {
                closeStream(in);
                closeStatement(stmt);
            }
        }
    }

    /**
     * Builds the SQL statements
     * <p/>
     * Since Oracle treats emtpy strings and BLOBs as null values the SQL
     * statements had to be adapated accordingly. The following changes were
     * necessary:
     * <ul>
     * <li>The distinction between file and folder entries is based on
     * FSENTRY_LENGTH being null/not null rather than FSENTRY_DATA being
     * null/not null because FSENTRY_DATA of a 0-length (i.e. empty) file is
     * null in Oracle.</li>
     * <li>Folder entries: Since the root folder has an empty name (which would
     * be null in Oracle), an empty name is automatically converted and treated
     * as " ".</li>
     * </ul>
     */
    protected void buildSQLStatements() {
        insertFileSQL = "insert into "
                + schemaObjectPrefix + "FSENTRY "
                + "(FSENTRY_PATH, FSENTRY_NAME, FSENTRY_DATA, "
                + "FSENTRY_LASTMOD, FSENTRY_LENGTH) "
                + "values (?, ?, ?, ?, ?)";

        insertFolderSQL = "insert into "
                + schemaObjectPrefix + "FSENTRY "
                + "(FSENTRY_PATH, FSENTRY_NAME, FSENTRY_LASTMOD, FSENTRY_LENGTH) "
                + "values (?, nvl(?, ' '), ?, null)";

        updateDataSQL = "update "
                + schemaObjectPrefix + "FSENTRY "
                + "set FSENTRY_DATA = ?, FSENTRY_LASTMOD = ?, FSENTRY_LENGTH = ? "
                + "where FSENTRY_PATH = ? and FSENTRY_NAME = ? "
                + "and FSENTRY_LENGTH is not null";

        updateLastModifiedSQL = "update "
                + schemaObjectPrefix + "FSENTRY set FSENTRY_LASTMOD = ? "
                + "where FSENTRY_PATH = ? and FSENTRY_NAME = ? "
                + "and FSENTRY_LENGTH is not null";

        selectExistSQL = "select 1 from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_NAME = nvl(?, ' ')";

        selectFileExistSQL = "select 1 from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_NAME = ? and FSENTRY_LENGTH is not null";

        selectFolderExistSQL = "select 1 from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_NAME = nvl(?, ' ') and FSENTRY_LENGTH is null";

        selectFileNamesSQL = "select FSENTRY_NAME from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_LENGTH is not null";

        selectFolderNamesSQL = "select FSENTRY_NAME from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_NAME != ' ' "
                + "and FSENTRY_LENGTH is null";

        selectFileAndFolderNamesSQL = "select FSENTRY_NAME from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_NAME != ' '";

        selectChildCountSQL = "select count(FSENTRY_NAME) from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ?  "
                + "and FSENTRY_NAME != ' '";

        selectDataSQL = "select nvl(FSENTRY_DATA, empty_blob()) from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_NAME = ? and FSENTRY_LENGTH is not null";

        selectLastModifiedSQL = "select FSENTRY_LASTMOD from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_NAME = nvl(?, ' ')";

        selectLengthSQL = "select nvl(FSENTRY_LENGTH, 0) from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_NAME = ? and FSENTRY_LENGTH is not null";

        deleteFileSQL = "delete from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_NAME = ? and FSENTRY_LENGTH is not null";

        deleteFolderSQL = "delete from "
                + schemaObjectPrefix + "FSENTRY where "
                + "(FSENTRY_PATH = ? and FSENTRY_NAME = nvl(?, ' ') and FSENTRY_LENGTH is null) "
                + "or (FSENTRY_PATH = ?) "
                + "or (FSENTRY_PATH like ?) ";

        copyFileSQL = "insert into "
                + schemaObjectPrefix + "FSENTRY "
                + "(FSENTRY_PATH, FSENTRY_NAME, FSENTRY_DATA, "
                + "FSENTRY_LASTMOD, FSENTRY_LENGTH) "
                + "select ?, ?, FSENTRY_DATA, "
                + "FSENTRY_LASTMOD, FSENTRY_LENGTH from "
                + schemaObjectPrefix + "FSENTRY where FSENTRY_PATH = ? "
                + "and FSENTRY_NAME = ? and FSENTRY_LENGTH is not null";

        copyFilesSQL = "insert into "
                + schemaObjectPrefix + "FSENTRY "