java代碼對MongoDB的CRUD

java操作Mongo
工具類：
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.MongoClient;


public class MongoDBUtil {
private static MongoClient mongo;
private static DB db;

static{
//1,建立鏈接
try {
mongo = new MongoClient("localhost", 27017);
//2,得到數據庫對象
db = mongo.getDB("tj");
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

//得到表對象:文檔對象
public static DBCollection getDBCollection(String tableName){
return db.getCollection(tableName);
}

//關閉
public static void closeDB(){
if(mongo!=null){
mongo.close();
}
}


}








add:
批量添加可以提高性能
//批量添加性能更優
public void addGbls(){
DBCollection dbCollection = MongoDBUtil.getDBCollection("gbl");
List<DBObject> list = new ArrayList<DBObject>();
DBObject jo = new BasicDBObject();
jo.put("chihuo", "包子2");
jo.put("tjdesc", "包子也是很白的2");
jo.put("baifumei", "包子比我白2");
list.add(jo);

DBObject jo2 = new BasicDBObject();
jo2.put("chihuo", "222");
jo2.put("tjdesc", "8.22");
jo2.put("baifumei", "2222");
list.add(jo2);

dbCollection.insert(list);
}


delete:
//刪除
public void delGbl(String id){
DBCollection dbCollection = MongoDBUtil.getDBCollection("gbl");
DBObject o = new BasicDBObject("_id", new ObjectId(id));
dbCollection.remove(o);
}




update:
//修改
public void updateGbl(String id,String baifumei){
DBCollection dbCollection = MongoDBUtil.getDBCollection("gbl");
DBObject q=new BasicDBObject("_id", new ObjectId(id));
DBObject o=new BasicDBObject();//需要修改的內容，但是需要加$set,回憶：{$set:{key:value}}:json嵌套
o.put("$set", new BasicDBObject("baifumei",baifumei ));//需要把目標的 Object變成 JSON
dbCollection.update(q, o);
}
注意：JSON嵌套


find:


按照主鍵查找某條記錄：
public void findByID(String id){
DBCollection dbCollection = MongoDBUtil.getDBCollection("gbl");
DBObject ref = new BasicDBObject("_id", new ObjectId(id));
DBCursor dbCursor = dbCollection.find(ref);
while(dbCursor.hasNext()){//判斷是否有記錄
BasicDBObject data = (BasicDBObject)dbCursor.next();
ObjectId objectId = data.getObjectId("_id");
System.out.println(objectId.toString());
String chihuo = data.getString("chihuo");
String tjdesc = data.getString("tjdesc");
String baifumei = data.getString("baifumei");
System.out.println(chihuo+"\t"+tjdesc+"\t"+baifumei);
}
}


//查詢所有
public void findALL(){
DBCollection dbCollection = MongoDBUtil.getDBCollection("gbl");
DBCursor dbCursor = dbCollection.find();//不給條件就是查詢所有
while(dbCursor.hasNext()){//判斷是否有記錄
BasicDBObject data = (BasicDBObject)dbCursor.next();
ObjectId objectId = data.getObjectId("_id");
String chihuo = data.getString("chihuo");
String tjdesc = data.getString("tjdesc");
String baifumei = data.getString("baifumei");
System.out.println(objectId.toString()+"\t"+chihuo+"\t"+tjdesc+"\t"+baifumei);
}
}
 


模糊查詢：
//模糊查詢
public void findByLike(String tjdesc){
DBCollection dbCollection = MongoDBUtil.getDBCollection("gbl");

DBObject ref = new BasicDBObject();
//模糊條件Object
Pattern pattern = Pattern.compile("^.*"+tjdesc+".*$");
ref.put("tjdesc", pattern);
DBCursor find = dbCollection.find(ref);
while(find.hasNext()){
BasicDBObject data = (BasicDBObject)find.next();
ObjectId objectId = data.getObjectId("_id");
String chihuo = data.getString("chihuo");
String tj = data.getString("tjdesc");
String baifumei = data.getString("baifumei");
System.out.println(objectId.toString()+"\t"+chihuo+"\t"+tj+"\t"+baifumei);
}
}


分頁查詢：
//分頁
public void findByPage(int start,int size){
DBCollection dbCollection = MongoDBUtil.getDBCollection("gbl");
DBCursor limit = dbCollection.find().skip(start).limit(size);
while(limit.hasNext()){
BasicDBObject data = (BasicDBObject)limit.next();
ObjectId objectId = data.getObjectId("_id");
String chihuo = data.getString("chihuo");
String tj = data.getString("tjdesc");
String baifumei = data.getString("baifumei");
System.out.println(objectId.toString()+"\t"+chihuo+"\t"+tj+"\t"+baifumei);
}
}


對數據做封裝到POJO：
實體對象JavaBean:
public void addGbl(GblPOJO pojo){//注意：POJO需要轉化成BasicDBObject對象才能呢存入數據庫
try {
//1,建立鏈接
MongoClient mongo = new MongoClient("localhost", 27017);
//2,得到數據庫對象
DB db = mongo.getDB("tj");
//3，得到表對象
DBCollection collection = db.getCollection("gbl");
//4,操作數據
DBObject jo = new BasicDBObject();
jo.put("chihuo", pojo.getChihuo());
jo.put("tjdesc", pojo.getTjdesc());
jo.put("baifumei", pojo.getBaifumei());
collection.save(jo);
//5,關閉
mongo.close();
} catch (UnknownHostException e) {
e.printStackTrace();
}
}


//批量添加性能更優
public void addGbls(List<GblPOJO> pojos){
DBCollection dbCollection = MongoDBUtil.getDBCollection("gbl");
List<DBObject> list = new ArrayList<DBObject>();

for (GblPOJO pojo : pojos) {
DBObject jo = new BasicDBObject();
jo.put("chihuo", pojo.getChihuo());
jo.put("tjdesc", pojo.getTjdesc());
jo.put("baifumei", pojo.getBaifumei());
list.add(jo);
}

dbCollection.insert(list);
}