MongoDBUtil.java

/*
 * Copyright 2015-2025 the original author or authors.
 * 
 * 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 sockslib.utils.mongo;

import com.google.common.collect.Lists;
import com.mongodb.MongoClient;
import com.mongodb.MongoCredential;
import com.mongodb.ServerAddress;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.result.DeleteResult;
import org.apache.logging.log4j.util.Strings;
import org.bson.Document;

/**
 * The class <code>MongoDBUtil</code> is tool class for MongoDB.
 *
 * @author Youchao Feng
 * @version 1.0
 * @date Aug 23, 2015
 */
public class MongoDBUtil {

  private String host;
  private int port = 27017;
  private String username;
  private String password;
  private String databaseName;
  private MongoClient mongoClient;

  public MongoDBUtil() {
  }

  public MongoDBUtil(String host, int port, String databaseName) {
    this.host = host;
    this.port = port;
    this.databaseName = databaseName;
  }

  public MongoDBUtil(String host, int port, String databaseName, String username, String password) {
    this.host = host;
    this.port = port;
    this.databaseName = databaseName;
    this.username = username;
    this.password = password;
  }

  public DeleteResult deleteAll(String collectionName) {
    return execute(collectionName, collection -> collection.deleteMany(new Document()));
  }

  public void dropCollection(String collectionName) {
    execute(collectionName, collection -> {
      collection.drop();
      return null;
    });
  }

  public <T> T execute(String collectionName, CollectionCallback<T> callback) {
    MongoDatabase database = null;
    if (mongoClient == null) {
      mongoClient = getConnectedClient();
    }
    return callback.doInCollection(
        mongoClient.getDatabase(databaseName).getCollection(collectionName));
  }

  public void closeConnection() {
    if (mongoClient != null) {
      mongoClient.close();
    }
  }

  /**
   * Connect MongoDB and call callback, close connection at last.
   *
   * @param collectionName Collection name.
   * @param callback       Callback
   * @param <T>            The type of value which you want to return.
   * @return The value which callback returned.
   */
  public <T> T connect(String collectionName, CollectionCallback<T> callback) {
    MongoClient client = null;
    T t = null;
    try {
      client = getConnectedClient();
      MongoDatabase database = client.getDatabase(databaseName);
      MongoCollection<Document> collection = database.getCollection(collectionName);
      t = callback.doInCollection(collection);
    } finally {
      if (client != null) {
        client.close();
      }
    }
    return t;
  }

  public MongoCollection getCollection(String collectionName) {
    if (mongoClient == null) {
      mongoClient = getConnectedClient();
    }
    return mongoClient.getDatabase(databaseName).getCollection(collectionName);
  }

  private MongoClient getConnectedClient() {
    if (Strings.isEmpty(username)) {
      return new MongoClient(host, port);
    } else {
      MongoCredential credential =
          MongoCredential.createCredential(username, databaseName, password.toCharArray());
      return new MongoClient(new ServerAddress(host, port), Lists.newArrayList(credential));
    }
  }
}