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java操作mongodb示例分享

更新時間：2014年02月28日 10:29:00 作者：

這篇文章主要介紹了java操作mongodb示例,實現(xiàn)了簡單的條件查詢和復(fù)雜的條件查詢,需要的朋友可以參考下

package mymaven;  

import java.net.UnknownHostException;  
import java.util.Set;  

import com.mongodb.BasicDBObject;  
import com.mongodb.DB;  
import com.mongodb.DBCollection;  
import com.mongodb.DBCursor;  
import com.mongodb.DBObject;  
import com.mongodb.Mongo;  
import com.mongodb.MongoException;  

public class Test {  
    public static void main(String[] args) throws UnknownHostException, MongoException {  
        Mongo mongo = new Mongo("172.27.9.104", 27017);     // 連接數(shù)據(jù)庫  
        DB db = mongo.getDB("mytestdb");                    // 數(shù)據(jù)庫  
        Set<String> cols = db.getCollectionNames();           // 獲取數(shù)據(jù)庫中所有的集合（類似于獲取關(guān)系數(shù)據(jù)庫中的表）  

        // 打印出數(shù)據(jù)庫中的集合，這里應(yīng)當(dāng)為null  
        for (String s : cols) {  
            System.out.println(s);  
        }  

        DBCollection collection = db.getCollection("mytestcoll");       // 創(chuàng)建一個集合  
        collection.drop();                                              // 刪除集合，插入數(shù)據(jù)時自動重建  
        BasicDBObject obj = new BasicDBObject();                        // 初始化一個基本DB對象，插入數(shù)據(jù)庫的就是DB對象  

        obj.put("from", "blog.ithomer.net");        // 放入幾個鍵值對  
        obj.put("to", "forum.ithomer.net");  
        obj.put("subject", "ithomer.net");  
        collection.insert(obj);                     // 插入對象  

        DBObject dbobj = collection.findOne();      // 查看一條記錄，findOne()=find().limit(1);  
        System.out.println(dbobj);                  // 打印出剛才插入的數(shù)據(jù)  

        // 插入10條{ranking:i}的數(shù)據(jù)  
        for (int i = 0; i < 10; i++) {  
            collection.insert(new BasicDBObject().append("ranking", i));  
        }  
        System.out.println("count: " + collection.getCount());      // 打印集合中的數(shù)據(jù)總數(shù)  

          
        DBCursor cursor = collection.find();        // 然后我們使用這個游標(biāo)來遍歷集合  
        while (cursor.hasNext()) {  
            System.out.println(cursor.next());  
        }  
        // 簡單的條件查詢，查詢ranking為1的記錄  
        BasicDBObject query = new BasicDBObject();  
        query.put("ranking", 1);  
        cursor = collection.find(query);  
        System.out.println("collection find({\"ranking\":1}):");  
        while (cursor.hasNext()) {  
            System.out.println(cursor.next());  
        }  

        // 復(fù)雜的條件查詢，查詢ranking大于等于5小于9的記錄  
        query = new BasicDBObject();  
        query.put("ranking", new BasicDBObject("$gte", 5).append("$lt", 9));  
        cursor = collection.find(query);  
        System.out.println("collection find({\"ranking\":[5-9)}):");  
        while (cursor.hasNext()) {  
            System.out.println(cursor.next());  
        }  

//      mongo.dropDatabase("mytestdb");         // 最后刪除我們的測試數(shù)據(jù)庫  
    }  
}  

運行結(jié)果：

復(fù)制代碼代碼如下:

mytestcoll
system.indexes
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10107"} , "from" : "blog.ithomer.net" , "to" : "forum.ithomer.net" , "subject" : "ithomer.net"}
count: 11
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10107"} , "from" : "blog.ithomer.net" , "to" : "forum.ithomer.net" , "subject" : "ithomer.net"}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10108"} , "ranking" : 0}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10109"} , "ranking" : 1}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010a"} , "ranking" : 2}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010b"} , "ranking" : 3}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010c"} , "ranking" : 4}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010d"} , "ranking" : 5}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010e"} , "ranking" : 6}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010f"} , "ranking" : 7}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10110"} , "ranking" : 8}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10111"} , "ranking" : 9}
collection find({"ranking":1}):
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10109"} , "ranking" : 1}
collection find({"ranking":[5-9)}):
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010d"} , "ranking" : 5}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010e"} , "ranking" : 6}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010f"} , "ranking" : 7}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10110"} , "ranking" : 8}

mongodb數(shù)組示例：

復(fù)制代碼代碼如下:

@SuppressWarnings("unchecked")
public static void loadMediaTags(List<MediaEntity> mediaEntityList) {
  mediaEntityList.clear();

  try {
   Mongo mongo = new Mongo(CosineCluster.gMongo_HOST, CosineCluster.gMongo_PORT);
   DB db = mongo.getDB(CosineCluster.gMongo_DB);
   DBCollection collection = db.getCollection(CosineCluster.gMongo_Coll_Media);

   DBCursor cursor = collection.find();
   int index = 0;
   long startTime = System.currentTimeMillis();
   while(cursor.hasNext()){
    BasicDBObject obj = (BasicDBObject) cursor.next();

    long id = obj.getLong("_id");
    ArrayList<String> tagList = (ArrayList<String>) obj.get("tag");     // tag
    ArrayList<String> keywordList = (ArrayList<String>)obj.get("keyword");   // keyword
    ArrayList<Integer> copyrightList = (ArrayList<Integer>)obj.get("copyright"); // copyright


    MediaEntity mediaEntity = new MediaEntity();

    mediaEntity.setId(id);

    // tag
    for(int j=0; j<tagList.size(); j++) {
     mediaEntity.addTag(tagList.get(j));
     int tagId = getTagInt(tagList.get(j));
     mediaEntity.addTag(tagId);
    }

    // actors
    ArrayList<DBObject> actorsObjList = (ArrayList<DBObject>)obj.get("actors");  // actors
    for(int j=0; j<actorsObjList.size(); j++) {
      mediaEntity.addActor((String) actorsObjList.get(j).get("name"));
      int actorId = getActorInt((String)actorsObjList.get(j).get("name"));
      mediaEntity.addActor(actorId);
    }

    // director
    ArrayList<DBObject> directorObjList = (ArrayList<DBObject>)obj.get("director"); // director
    for(int j=0; j<directorObjList.size(); j++) {
      mediaEntity.addDirector((String) directorObjList.get(j).get("name"));
      int directorId = getDirectorInt((String) directorObjList.get(j).get("name"));
      mediaEntity.addDirector(directorId);
    }

    // keyword
    for(int j=0; j<keywordList.size(); j++) {
     mediaEntity.addKeyword(keywordList.get(j));
     int keywordId = getKeywordInt(keywordList.get(j));
     mediaEntity.addKeyword(keywordId);
    }

    // copyright
    for(int j=0; j<copyrightList.size(); j++) {
     mediaEntity.addCopyright(copyrightList.get(j));
    }

    mediaEntityList.add(mediaEntity);

    index++;
    if(index > 100) {
     break;
    }
    System.out.println(index + " --- mediaEntity : " + mediaEntity.toString());
   }
   long costTime = System.currentTimeMillis() - startTime;
   System.out.println("load data costTime = " + index + "; costTime = " + costTime/1000f);

  } catch (Exception e) {
   e.printStackTrace();
  }
}

public static int getTagInt(String tag) {
  int tagIntId = -1;

  try {
   MongoClient mongo = new MongoClient(CosineCluster.gMongo_HOST, CosineCluster.gMongo_PORT);
   DB db = mongo.getDB(CosineCluster.gMongo_DB);
   DBCollection tagmapCollection = db.getCollection("recommend_tag_map");

   DBCursor cursor = tagmapCollection.find(new BasicDBObject("name", tag));
   if(cursor == null || cursor.toArray().size() <= 0) {  // 處理小于2或n的映射關(guān)鍵字，下同
    return tagIntId;
   }
   DBObject obj = cursor.toArray().get(0);


   String name = tag;
   tagIntId = (Integer) obj.get("id");
   int num = (Integer) obj.get("num");

   mongo.close();
  } catch (UnknownHostException e) {
   e.printStackTrace();
  }

  return tagIntId;
}

public static int getActorInt(String actor) {
  int actorIntId = -1;
  try {
   MongoClient mongo = new MongoClient(CosineCluster.gMongo_HOST, CosineCluster.gMongo_PORT);
   DB db = mongo.getDB(CosineCluster.gMongo_DB);
   DBCollection tagmapCollection = db.getCollection("recommend_actor_map");

   DBCursor cursor = tagmapCollection.find(new BasicDBObject("name", actor));
   if(cursor == null || cursor.toArray().size() <= 0) {
    return actorIntId;
   }
   DBObject obj = cursor.toArray().get(0);

   String name = actor;
   actorIntId = (Integer) obj.get("id");
   int num = (Integer) obj.get("num");

   mongo.close();
  } catch (UnknownHostException e) {
   e.printStackTrace();
  }

  return actorIntId;
}