JAVA单例MongoDB工具类
JAVA驱动版本：
<!– MongoDB驱动 –>
<dependency>
<groupId>org.mongodb</groupId>
<artifactId>mongo-java-driver</artifactId>
<version>3.0.2</version>
</dependency>
工具类代码如下：
package utils;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.configuration.CompositeConfiguration;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.bson.Document;
import org.bson.conversions.Bson;
import org.bson.types.ObjectId;
import com.mongodb.BasicDBObject;
import com.mongodb.MongoClient;
import com.mongodb.MongoClientOptions;
import com.mongodb.MongoClientOptions.Builder;
import com.mongodb.WriteConcern;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoIterable;
import com.mongodb.client.model.Filters;
import com.mongodb.client.result.DeleteResult;
/**
* MongoDB工具类 Mongo实例代表了一个数据库连接池，即使在多线程的环境中，一个Mongo实例对我们来说已经足够了<br>
* 注意Mongo已经实现了连接池，并且是线程安全的。 <br>
* 设计为单例模式， 因 MongoDB的Java驱动是线程安全的，对于一般的应用，只要一个Mongo实例即可，<br>
* Mongo有个内置的连接池（默认为10个） 对于有大量写和读的环境中，为了确保在一个Session中使用同一个DB时，<br>
* DB和DBCollection是绝对线程安全的<br>
*
* @author zhoulingfei
* @date 2015-5-29 上午11:49:49
* @version 0.0.0
* @Copyright (c)1997-2015 NavInfo Co.Ltd. All Rights Reserved.
*/
public enum MongoDBUtil {
/**
* 定义一个枚举的元素，它代表此类的一个实例
*/
instance;
private MongoClient mongoClient;
static {
System.out.println(“===============MongoDBUtil初始化========================”);
CompositeConfiguration config = new CompositeConfiguration();
try {
config.addConfiguration(new PropertiesConfiguration(“mongodb.properties”));
} catch (ConfigurationException e) {
e.printStackTrace();
}
// 从配置文件中获取属性值
String ip = config.getString(“host”);
int port = config.getInt(“port”);
instance.mongoClient = new MongoClient(ip, port);
// or, to connect to a replica set, with auto-discovery of the primary, supply a seed list of members
// List<ServerAddress> listHost = Arrays.asList(new ServerAddress(“localhost”, 27017),new ServerAddress(“localhost”, 27018));
// instance.mongoClient = new MongoClient(listHost);
// 大部分用户使用mongodb都在安全内网下，但如果将mongodb设为安全验证模式，就需要在客户端提供用户名和密码：
// boolean auth = db.authenticate(myUserName, myPassword);
Builder options = new MongoClientOptions.Builder();
// options.autoConnectRetry(true);// 自动重连true
// options.maxAutoConnectRetryTime(10); // the maximum auto connect retry time
options.connectionsPerHost(300);// 连接池设置为300个连接,默认为100
options.connectTimeout(15000);// 连接超时，推荐>3000毫秒
options.maxWaitTime(5000); //
options.socketTimeout(0);// 套接字超时时间，0无限制
options.threadsAllowedToBlockForConnectionMultiplier(5000);// 线程队列数，如果连接线程排满了队列就会抛出“Out of semaphores to get db”错误。
options.writeConcern(WriteConcern.SAFE);//
options.build();
}
// ————————————共用方法—————————————————
/**
* 获取DB实例 – 指定DB
*
* @param dbName
* @return
*/
public MongoDatabase getDB(String dbName) {
if (dbName != null && !””.equals(dbName)) {
MongoDatabase database = mongoClient.getDatabase(dbName);
return database;
}
return null;
}
/**
* 获取collection对象 – 指定Collection
*
* @param collName
* @return
*/
public MongoCollection<Document> getCollection(String dbName, String collName) {
if (null == collName || “”.equals(collName)) {
return null;
}
if (null == dbName || “”.equals(dbName)) {
return null;
}
MongoCollection<Document> collection = mongoClient.getDatabase(dbName).getCollection(collName);
return collection;
}
/**
* 查询DB下的所有表名
*/
public List<String> getAllCollections(String dbName) {
MongoIterable<String> colls = getDB(dbName).listCollectionNames();
List<String> _list = new ArrayList<String>();
for (String s : colls) {
_list.add(s);
}
return _list;
}
/**
* 获取所有数据库名称列表
*
* @return
*/
public MongoIterable<String> getAllDBNames() {
MongoIterable<String> s = mongoClient.listDatabaseNames();
return s;
}
/**
* 删除一个数据库
*/
public void dropDB(String dbName) {
getDB(dbName).drop();
}
/**
* 查找对象 – 根据主键_id
*
* @param collection
* @param id
* @return
*/
public Document findById(MongoCollection<Document> coll, String id) {
ObjectId _idobj = null;
try {
_idobj = new ObjectId(id);
} catch (Exception e) {
return null;
}
Document myDoc = coll.find(Filters.eq(“_id”, _idobj)).first();
return myDoc;
}
/** 统计数 */
public int getCount(MongoCollection<Document> coll) {
int count = (int) coll.count();
return count;
}
/** 条件查询 */
public MongoCursor<Document> find(MongoCollection<Document> coll, Bson filter) {
return coll.find(filter).iterator();
}
/** 分页查询 */
public MongoCursor<Document> findByPage(MongoCollection<Document> coll, Bson filter, int pageNo, int pageSize) {
Bson orderBy = new BasicDBObject(“_id”, 1);
return coll.find(filter).sort(orderBy).skip((pageNo – 1) * pageSize).limit(pageSize).iterator();
}
/**
* 通过ID删除
*
* @param coll
* @param id
* @return
*/
public int deleteById(MongoCollection<Document> coll, String id) {
int count = 0;
ObjectId _id = null;
try {
_id = new ObjectId(id);
} catch (Exception e) {
return 0;
}
Bson filter = Filters.eq(“_id”, _id);
DeleteResult deleteResult = coll.deleteOne(filter);
count = (int) deleteResult.getDeletedCount();
return count;
}
/**
* FIXME
*
* @param coll
* @param id
* @param newdoc
* @return
*/
public Document updateById(MongoCollection<Document> coll, String id, Document newdoc) {
ObjectId _idobj = null;
try {
_idobj = new ObjectId(id);
} catch (Exception e) {
return null;
}
Bson filter = Filters.eq(“_id”, _idobj);
// coll.replaceOne(filter, newdoc); // 完全替代
coll.updateOne(filter, new Document(“$set”, newdoc));
return newdoc;
}
public void dropCollection(String dbName, String collName) {
getDB(dbName).getCollection(collName).drop();
}
/**
* 关闭Mongodb
*/
public void close() {
if (mongoClient != null) {
mongoClient.close();
mongoClient = null;
}
}
/**
* 测试入口
*
* @param args
*/
public static void main(String[] args) {
String dbName = “GC_MAP_DISPLAY_DB”;
String collName = “COMMUNITY_BJ”;
MongoCollection<Document> coll = MongoDBUtil.instance.getCollection(dbName, collName);
// 插入多条
// for (int i = 1; i <= 4; i++) {
// Document doc = new Document();
// doc.put(“name”, “zhoulf”);
// doc.put(“school”, “NEFU” + i);
// Document interests = new Document();
// interests.put(“game”, “game” + i);
// interests.put(“ball”, “ball” + i);
// doc.put(“interests”, interests);
// coll.insertOne(doc);
// }
// // 根据ID查询
// String id = “556925f34711371df0ddfd4b”;
// Document doc = MongoDBUtil2.instance.findById(coll, id);
// System.out.println(doc);
// 查询多个
// MongoCursor<Document> cursor1 = coll.find(Filters.eq(“name”, “zhoulf”)).iterator();
// while (cursor1.hasNext()) {
// org.bson.Document _doc = (Document) cursor1.next();
// System.out.println(_doc.toString());
// }
// cursor1.close();
// 查询多个
// MongoCursor<Person> cursor2 = coll.find(Person.class).iterator();
// 删除数据库
// MongoDBUtil2.instance.dropDB(“testdb”);
// 删除表
// MongoDBUtil2.instance.dropCollection(dbName, collName);
// 修改数据
// String id = “556949504711371c60601b5a”;
// Document newdoc = new Document();
// newdoc.put(“name”, “时候”);
// MongoDBUtil.instance.updateById(coll, id, newdoc);
// 统计表
// System.out.println(MongoDBUtil.instance.getCount(coll));
// 查询所有
Bson filter = Filters.eq(“count”, 0);
MongoDBUtil.instance.find(coll, filter);
}
}
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