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java操作mongodb示例分享

2019年07月22日  | 移动技术网IT编程  | 我要评论

复制代码 代码如下:

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);     // 连接数据库 
        db db = mongo.getdb("mytestdb");                    // 数据库 
        set<string> cols = db.getcollectionnames();           // 获取数据库中所有的集合（类似于获取关系数据库中的表） 

        // 打印出数据库中的集合，这里应当为null 
        for (string s : cols) { 
            system.out.println(s); 
        } 

        dbcollection collection = db.getcollection("mytestcoll");       // 创建一个集合 
        collection.drop();                                              // 删除集合，插入数据时自动重建 
        basicdbobject obj = new basicdbobject();                        // 初始化一个基本db对象，插入数据库的就是db对象 

        obj.put("from", "blog.ithomer.net");        // 放入几个键值对 
        obj.put("to", "forum.ithomer.net"); 
        obj.put("subject", "ithomer.net"); 
        collection.insert(obj);                     // 插入对象 

        dbobject dbobj = collection.findone();      // 查看一条记录，findone()=find().limit(1); 
        system.out.println(dbobj);                  // 打印出刚才插入的数据 

        // 插入10条{ranking:i}的数据 
        for (int i = 0; i < 10; i++) { 
            collection.insert(new basicdbobject().append("ranking", i)); 
        } 
        system.out.println("count: " + collection.getcount());      // 打印集合中的数据总数 

         
        dbcursor cursor = collection.find();        // 然后我们使用这个游标来遍历集合 
        while (cursor.hasnext()) { 
            system.out.println(cursor.next()); 
        } 
        // 简单的条件查询，查询ranking为1的记录 
        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()); 
        } 

        // 复杂的条件查询，查询ranking大于等于5小于9的记录 
        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");         // 最后删除我们的测试数据库 
    } 
} 

运行结果：

复制代码 代码如下:

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数组示例：

复制代码 代码如下:

 @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) {  // 处理小于2或n的映射关键字，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;
 }

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