MongoDB的基本使用

淡淡回忆

　　最近用到了MongDB，就把所学的记录下。
　　首先上官网上下载最新的版本http://www.mongodb.org/downloads
　　解压后配置数据库路径，例如我的在D:\MongoDB，数据库路径是D:\MongoDB\data
　　在bin文件夹下输入命令mongod --dbpath D:\MongoDB\data，接着再输入mongo看看连接情况，若出现
　　Mongo Shell version：x.x.x
　　connecting to： test
　　则说明配置成功了，接下来我们就可以使用自己的mongdb了。
　　
　　对于数据库的基本使用也就是增删改查了



package edu.scut.italk.mongodb;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;
import org.bson.types.ObjectId;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.MongoOptions;
import edu.scut.log4j.Logs;
/**
* mongodb操作的工具类
*
*/
public class DBUtil {
private static MongoClient mongoClient = null;
private static DB db = null;
private static DBCollection dbCollection = null;
static {
try {
mongoClient = new MongoClient("127.0.0.1", 27017);
db = mongoClient.getDB("test");
db.createCollection("chatlogs", null);
dbCollection = db.getCollection("chatlogs");
} catch (UnknownHostException e) {
            e.printStackTrace();
}
}
/**
* 设置唯一性
*
* @param field 要设置的field
*/
public static void setUnique(String field) {
BasicDBObject basicDBObject = new BasicDBObject();
basicDBObject.put(field, 1);
dbCollection.ensureIndex(basicDBObject, "unique_key_name", true);
}
/**
* 插入数据库
*
* @param doc
*/
public static void insert(DBObject... doc) {
dbCollection.insert(doc);
}
/**
* 保存修改，如果数据库中不存在则插入，否则覆盖
*
* @param dbCollection
* @param dbObject 要保存的对象
* @return
*/
public static DBObject save(DBObject dbObject) {
dbCollection.save(dbObject);
return dbObject;
}
/**
* 根据id查找并返回得到的BasicObject对象
*
* @param dbCollection
* @param id
* @return
*/
public static BasicObject findById(String id) {
BasicObject basicObject = null;
BasicObject query = new BasicObject();
query.put("_id", new ObjectId(id));
DBObject mOb = dbCollection.findOne(query);
if(null != mOb)
basicObject = new BasicObject(mOb.toMap());
return basicObject;
}
/**
* 查找children域为null的basicObject对象
*
* @param dbCollection
* @return 返回一个包含多个basicobject对象的list
*/
public static List findNoChildren() {
BasicObject basicObject = new BasicObject();
basicObject.setChildren(null);
DBCursor dbCursor = dbCollection.find(basicObject);
List list = new ArrayList();
for (DBObject dbObject : dbCursor) {
list.add(new BasicObject(dbObject.toMap()));
}
dbCursor.close();
return list.size() > 0 ? list : null;
}
/**
* 根据content查找并返回得到的BasicObject对象
*
* @param dbCollection
* @param content
* @return
*/
public static BasicObject findByContent(String content) {
BasicObject basicObject = null;
DBObject mOb = dbCollection.findOne(new BasicObject("content", content));
if(null != mOb)
basicObject = new BasicObject(mOb.toMap());
return basicObject;
}
/**
* 遍历全部
*
* @return
*/
public static DBCursor findAll() {
return dbCollection.find();
}
public static void remove(DBObject dbObject) {
dbCollection.remove(dbObject);
}
/**
* 关闭mongoclient
*/
public static void closeClient() {
if(null != mongoClient) {
mongoClient.close();
}
}
public static void dropDB() {
db.dropDatabase();
}
}
　　以上基本把我们需要的操作都加载该工具类中，
　　使用时像这样



        System.out.println("==================findAll============================");
DBCursor dbCursor = DBUtil.findAll();
for (DBObject dbObject : dbCursor) {
System.out.println(dbObject);
}
dbCursor.close();
System.out.println("=====================================================");