org.lightcouch.CouchDbContext.java Source code

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Here is the source code for org.lightcouch.CouchDbContext.java

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/*
 * Copyright (C) 2011 Ahmed Yehia (ahmed.yehia.m@gmail.com)
 *
 * 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 org.lightcouch;

import static org.lightcouch.CouchDbUtil.*;
import static org.lightcouch.URIBuilder.*;

import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Type;
import java.net.URI;
import java.nio.charset.Charset;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPut;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.reflect.TypeToken;

/**
 * Provides access to database APIs.
 * @author Ahmed Yehia
 */
public class CouchDbContext {

    private static final Log log = LogFactory.getLog(CouchDbContext.class);

    private CouchDbClient dbc;

    CouchDbContext(CouchDbClient dbc) {
        this.dbc = dbc;
        CouchDbProperties props = dbc.getConfig().getProperties();
        if (props.isCreateDbIfNotExist()) {
            createDB(props.getDbName());
        } else {
            serverVersion(); // pre warm up client
        }
    }

    /**
     * Deletes a database.
     * @param dbName The database name to delete
     * @param confirm For double checking, the text "delete database" must be supplied.
     */
    public void deleteDB(String dbName, String confirm) {
        assertNotEmpty(dbName, "Database name");
        if (!"delete database".equals(confirm))
            throw new IllegalArgumentException("Cannot delete database without confirmation!");
        dbc.delete(builder(dbc.getBaseUri()).path(dbName).build());
    }

    /**
     * Creates a new Database, if it does not already exist.
     * @param dbName The Database name
     */
    public void createDB(String dbName) {
        assertNotEmpty(dbName, "Database name");
        HttpResponse headresp = null;
        HttpResponse putresp = null;
        URI uri = builder(dbc.getBaseUri()).path(dbName).build();
        try {
            headresp = dbc.head(uri);
        } catch (NoDocumentException e) { // db doesn't exist
            HttpPut put = new HttpPut(uri);
            putresp = dbc.executeRequest(put);
            log.info(String.format("Database: '%s' is created.", dbName));
        } finally {
            close(headresp);
            close(putresp);
        }
    }

    /**
     * @return All server databases.
     */
    public List<String> getAllDbs() {
        InputStream instream = null;
        try {
            Type typeOfList = new TypeToken<List<String>>() {
            }.getType();
            instream = dbc.get(builder(dbc.getBaseUri()).path("_all_dbs").build());
            Reader reader = new InputStreamReader(instream);
            return dbc.getGson().fromJson(reader, typeOfList);
        } finally {
            close(instream);
        }
    }

    /**
     * Gets the info of the associated database instance with this client.
     * @return {@link CouchDbInfo}
     */
    public CouchDbInfo info() {
        return dbc.get(builder(dbc.getDBUri()).build(), CouchDbInfo.class);
    }

    /**
     * @return CouchDB server version.
     */
    public String serverVersion() {
        InputStream instream = null;
        try {
            instream = dbc.get(builder(dbc.getBaseUri()).build());
            Reader reader = null;
            try {
                reader = new InputStreamReader(instream, "UTF-8");
            } catch (UnsupportedEncodingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return getElement(new JsonParser().parse(reader).getAsJsonObject(), "version");
        } finally {
            close(instream);
        }
    }

    /**
     * Triggers a database compaction request.
     */
    public void compact() {
        HttpResponse response = null;
        try {
            response = dbc.post(builder(dbc.getDBUri()).path("_compact").build(), "");
        } finally {
            close(response);
        }
    }

    /**
     * Requests the database commits any recent changes to disk.
     */
    public void ensureFullCommit() {
        HttpResponse response = null;
        try {
            response = dbc.post(builder(dbc.getDBUri()).path("_ensure_full_commit").build(), "");
        } finally {
            close(response);
        }
    }

    /**
     * Request a database sends a list of UUIDs.
     * @param count The count of UUIDs.
     */
    public List<String> uuids(long count) {
        String uri = String.format("%s_uuids?count=%d", dbc.getBaseUri(), count);
        JsonObject json = dbc.findAny(JsonObject.class, uri);
        return dbc.getGson().fromJson(json.get("uuids").toString(), new TypeToken<List<String>>() {
        }.getType());
    }
}