JAVA单例MongoDB工具类

2021-09-23 11:14:14 浏览数 (1)

JAVA驱动版本:

代码语言:javascript复制
       <!-- 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:

代码语言:javascript复制
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);
}




}</pre> 

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