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这是获取mongoClient实例的工具类
import java.util.ArrayList;
import java.util.List;
import java.util.ResourceBundle;
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.MongoCredential;
import com.mongodb.ServerAddress;
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（2.10.0版以后 默认为100个）<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 MongoDBUtils {
/**
* 定义一个枚举的元素，它代表此类的一个实例
*/
INSTANCE;
private static String userName;
private static char[] pwd;
private static String dbName;
private static String replicaSet;
private MongoClient mongoClient;
private MongoDBUtils() {
System.out.println("执行构造函数！");
}
static {
System.out.println("===============MongoDBUtil初始化========================");
ResourceBundle rb = ResourceBundle.getBundle("demo");
userName = rb.getString("username");
pwd = rb.getString("password").toCharArray();
dbName = rb.getString("dbname");
replicaSet = rb.getString("replicaSet");
List<MongoCredential> credentialsList = new ArrayList<MongoCredential>();
List<ServerAddress> seeds = replicaSet(replicaSet);
MongoCredential mc = MongoCredential.createCredential(userName, dbName, pwd);
credentialsList.add(mc);
Builder builder = new MongoClientOptions.Builder();
builder.connectionsPerHost(300);// 连接池设置为300个连接,默认为100 与目标数据库能够建立的最大connection数量
builder.connectTimeout(15000);// 连接超时，推荐>3000毫秒
builder.maxWaitTime(5000); //最大等待连接的线程阻塞时间
builder.socketTimeout(0);// 套接字超时时间，0无限制
builder.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。
MongoClientOptions options = builder.build();
INSTANCE.mongoClient = new MongoClient(seeds,credentialsList,options);
}
/**
* 副本集
* @param serverAddress
*/
public static List<ServerAddress> replicaSet(String serverAddress){
List<ServerAddress> setList = new ArrayList<ServerAddress>();
String[] serverAddres= serverAddress.split(",");
for(int i=0;i<serverAddres.length;i++){
String[] server=serverAddres[i].split(":");
setList.add(new ServerAddress(server[0], Integer.parseInt(server[1])));
}
return setList;
}
/**
* 获取DB实例
*
* @return
*/
public MongoDatabase getDB() {
MongoDatabase database = mongoClient.getDatabase(dbName);
return database;
}
/**
* 获取collection对象 - 指定Collection
*
* @param collName
* @return
*/
public MongoCollection<Document> getCollection(String collName) {
if (null == collName || "".equals(collName)) {
return null;
}
MongoCollection<Document> collection = mongoClient.getDatabase(dbName).getCollection(collName);
return collection;
}
/**
* 查询DB下的所有Collection名称
*/
public List<String> getAllCollections() {
MongoIterable<String> colls = getDB().listCollectionNames();
List<String> list = new ArrayList<String>();
for (String s : colls) {
list.add(s);
}
return list;
}
/**
* 关闭Mongodb
*/
public void close() {
if (mongoClient != null) {
mongoClient.close();
mongoClient = null;
}
}
/**
* 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;
}
/*
* 测试
*/
public static void main(String[] args) {
MongoCollection<Document> obj1 = MongoDBUtils.INSTANCE.getCollection("Atest");
MongoClient mongoClient1 = MongoDBUtils.INSTANCE.mongoClient;
MongoCollection<Document> obj2 = MongoDBUtils.INSTANCE.getCollection("test");
MongoClient mongoClient2 = MongoDBUtils.INSTANCE.mongoClient;
//输出结果：obj1==obj2?true
System.out.println(obj1);
System.out.println(obj2);
System.out.println(mongoClient1);
System.out.println(mongoClient2);
System.out.println("mongoClient1==mongoClient2?" + (mongoClient1==mongoClient2));
System.out.println("obj1==obj2?" + (obj1==obj2));
}
}
mongodb
java
这是一个问题吗？ 不是已经弄好了？