com.jpeterson.littles3.dao.je.JeBucketDao.java Source code

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Here is the source code for com.jpeterson.littles3.dao.je.JeBucketDao.java

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/*
 * Copyright 2007 Jesse Peterson
 * 
 * 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.
 */

package com.jpeterson.littles3.dao.je;

import java.io.UnsupportedEncodingException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.dao.DataAccessException;
import org.springframework.dao.DataAccessResourceFailureException;
import org.springframework.dao.DataRetrievalFailureException;

import com.jpeterson.littles3.bo.Bucket;
import com.jpeterson.littles3.dao.BucketDao;
import com.sleepycat.bind.tuple.TupleBinding;
import com.sleepycat.je.Database;
import com.sleepycat.je.DatabaseEntry;
import com.sleepycat.je.DatabaseException;
import com.sleepycat.je.LockMode;
import com.sleepycat.je.OperationStatus;

/**
 * An implementation of <code>BucketDao</code> that uses Oracle Berkeley DB
 * Java Edition to index and manage the bucket's meta data.
 * 
 * @author Jesse Peterson
 */
public class JeBucketDao implements BucketDao {
    private TupleBinding bucketBinding = new BucketTupleBinding();

    private JeCentral jeCentral;

    private Log logger;

    public JeBucketDao() {
        super();
        logger = LogFactory.getLog(this.getClass());
        logger.debug("JeBucketDao created");
    }

    /**
     * This method retrieves the <code>Bucket</code> representation of a
     * bucket from the underlying JE database via the bucket's name.
     * 
     * @param bucket
     *            The bucket name.
     * @throws DataRetrievalFailureException
     *             Could not find the <code>Bucket</code> for the provided
     *             <code>bucket</code> name.
     * @throws DataAccessResourceFailureException
     *             General failure retrieving the bucket from the JE database.
     * @throws DataAccessException
     *             General failure retrieving the bucket.
     */
    public Bucket loadBucket(String bucket) throws DataAccessException {
        DatabaseEntry theKey;
        DatabaseEntry theData;

        // Environment myDbEnvironment = null;
        Database database = null;

        try {
            theKey = new DatabaseEntry(bucket.getBytes("UTF-8"));
            theData = new DatabaseEntry();

            database = jeCentral.getDatabase(JeCentral.BUCKET_DB_NAME);

            if (database.get(null, theKey, theData, LockMode.DEFAULT) == OperationStatus.SUCCESS) {
                return (Bucket) bucketBinding.entryToObject(theData);
            } else {
                throw new DataRetrievalFailureException("Could not find Bucket: " + bucket);
            }
        } catch (DatabaseException e) {
            throw new DataAccessResourceFailureException("Unable to load a database record", e);
        } catch (UnsupportedEncodingException e) {
            // should not happen
            e.printStackTrace();
            throw new DataAccessResourceFailureException("Unexpected encoding error", e);
        }
    }

    public void storeBucket(Bucket bucket) throws DataAccessException {
        DatabaseEntry theKey;
        DatabaseEntry theData;

        // Environment myDbEnvironment = null;
        Database database = null;

        try {
            theKey = new DatabaseEntry(bucket.getName().getBytes("UTF-8"));
            theData = new DatabaseEntry();
            bucketBinding.objectToEntry(bucket, theData);

            database = jeCentral.getDatabase(JeCentral.BUCKET_DB_NAME);

            database.put(null, theKey, theData);
        } catch (DatabaseException e) {
            throw new DataAccessResourceFailureException("Unable to load a database record", e);
        } catch (UnsupportedEncodingException e) {
            // should not happen
            e.printStackTrace();
        }
    }

    public void removeBucket(Bucket bucket) throws DataAccessException {
        DatabaseEntry theKey;

        // Environment myDbEnvironment = null;
        Database database = null;

        try {
            theKey = new DatabaseEntry(bucket.getName().getBytes("UTF-8"));

            database = jeCentral.getDatabase(JeCentral.BUCKET_DB_NAME);

            database.delete(null, theKey);
        } catch (DatabaseException e) {
            throw new DataAccessResourceFailureException("Unable to load a database record", e);
        } catch (UnsupportedEncodingException e) {
            // should not happen
            e.printStackTrace();
        }
    }

    public JeCentral getJeCentral() {
        return jeCentral;
    }

    public void setJeCentral(JeCentral jeCentral) {
        this.jeCentral = jeCentral;
    }
}