java操作mongoDB数据库的简单实例

首先导入mongoDB的jar包 http://pan.baidu.com/s/1bnGMJRD

//DataBase.java

package com.mongodb.test;

import java.net.UnknownHostException;

import com.mongodb.DB; 
import com.mongodb.DBCollection; 
import com.mongodb.DBCursor; 
import com.mongodb.DBObject; 
import com.mongodb.Mongo; 
import com.mongodb.MongoException; 
import com.mongodb.util.JSON;

public class DataBase { 
 public static void main(String[] args) 
  throws UnknownHostException, MongoException { 
  //1.建立一个Mongo的数据库连接对象 
  Mongo mg = new Mongo("127.0.0.1:27017"); 
        //查询所有的Database 
        for (String name : mg.getDatabaseNames()) { 
            System.out.println("dbName: " + name); 
        } 
        //2.创建相关数据库的连接 
        DB db = mg.getDB("foobar"); 
        //查询数据库所有的集合 
        for (String name : db.getCollectionNames()) { 
            System.out.println("collectionName: " + name); 
        } 
        
        DBCollection users = db.getCollection("persons"); 
        //查询所有的数据 
        DBCursor cur = users.find(); 
        while (cur.hasNext()) { 
         DBObject object = cur.next(); 
         System.out.println(object.get("name")); 
        } 
        System.out.println(cur.count()); 
        System.out.println(cur.getCursorId()); 
        System.out.println(JSON.serialize(cur)); 
    } 
} 
//MongoDb.java

package com.mongodb.test;

import java.net.UnknownHostException; 
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.Mongo; 
import com.mongodb.MongoException;

public class MongoDb { 
 //1.建立一个Mongo的数据库连接对象 
 static Mongo connection = null; 
 //2.创建相关数据库的连接 
 static DB db = null; 
 public MongoDb(String dbName) throws UnknownHostException, MongoException{ 
  connection = new Mongo("127.0.0.1:27017"); 
  db = connection.getDB(dbName); 
 } 
 public static void main(String[] args) throws UnknownHostException, MongoException { 
  //实例化 
  MongoDb mongoDb = new MongoDb("foobar"); 
     /** 
      * 1.创建一个名字叫javadb的数据库 
      */ 
//  mongoDb.createCollection("javadb"); 
  /** 
   * 2.为集合javadb添加一条数据 
   */ 
//  DBObject dbs = new BasicDBObject(); 
//  dbs.put("name", "uspcat.com"); 
//  dbs.put("age", 2); 
//  List<String>  books = new ArrayList<String>(); 
//  books.add("EXTJS"); 
//  books.add("MONGODB"); 
//  dbs.put("books", books); 
//  mongoDb.insert(dbs, "javadb"); 
  /** 
   * 3.批量插入数据 
   */ 
//  List<DBObject> dbObjects = new ArrayList<DBObject>(); 
//  DBObject jim = new BasicDBObject("name","jim"); 
//  DBObject lisi = new BasicDBObject("name","lisi"); 
//  dbObjects.add(jim); 
//  dbObjects.add(lisi); 
//  mongoDb.insertBatch(dbObjects, "javadb"); 
  /** 
   * 4.根据ID删除数据 
   */ 
//  mongoDb.deleteById("502870dab9c368bf5b151a04", "javadb"); 
  /** 
   * 5.根据条件删除数据 
   */ 
//  DBObject lisi = new BasicDBObject(); 
//  lisi.put("name", "lisi"); 
//  int count = mongoDb.deleteByDbs(lisi, "javadb"); 
//  System.out.println("删除数据的条数是: "+count); 
  /** 
   * 6.更新操作,为集合增加email属性 
   */ 
//  DBObject update = new BasicDBObject(); 
//  update.put("$set", 
//    new BasicDBObject("eamil","test @126.com")); 
//  mongoDb.update(new BasicDBObject(), 
//    update,false,true,"javadb"); 
  /** 
   * 7.查询出persons集合中的name和age 
   */ 
//  DBObject keys = new BasicDBObject(); 
//  keys.put("_id", false); 
//  keys.put("name", true); 
//  keys.put("age", true); 
//  DBCursor cursor = mongoDb.find(null, keys, "persons"); 
//     while (cursor.hasNext()) { 
//      DBObject object = cursor.next(); 
//      System.out.println(object.get("name")); 
//     } 
     /** 
      * 7.查询出年龄大于26岁并且英语成绩小于80分 
      */ 
//  DBObject ref = new BasicDBObject(); 
//  ref.put("age", new BasicDBObject("$gte",26)); 
//  ref.put("e", new BasicDBObject("$lte",80)); 
//  DBCursor cursor = mongoDb.find(ref, null, "persons"); 
//     while (cursor.hasNext()) { 
//      DBObject object = cursor.next(); 
//      System.out.print(object.get("name")+"-->"); 
//      System.out.print(object.get("age")+"-->"); 
//      System.out.println(object.get("e")); 
//     } 
  /** 
   * 8.分页例子 
   */ 
  DBCursor cursor = mongoDb.find(null, null, 0, 3, "persons"); 
     while (cursor.hasNext()) { 
      DBObject object = cursor.next(); 
      System.out.print(object.get("name")+"-->"); 
      System.out.print(object.get("age")+"-->"); 
      System.out.println(object.get("e")); 
     }   
  //关闭连接对象 
  connection.close(); 
 } 
 /** 
  * 穿件一个数据库集合 
  * @param collName 集合名称 
  * @param db  数据库实例 
  */ 
 public void createCollection(String collName){ 
  DBObject dbs = new BasicDBObject(); 
  db.createCollection("javadb", dbs); 
 } 
 /** 
  * 为相应的集合添加数据 
  * @param dbs 
  * @param collName 
  */ 
 public void insert(DBObject dbs,String collName){ 
  //1.得到集合 
  DBCollection coll = db.getCollection(collName); 
  //2.插入操作 
  coll.insert(dbs); 
 } 
 /** 
  * 为集合批量插入数据 
  * @param dbses 
  * @param collName 
  */ 
 public void insertBatch(List<DBObject> dbses,String collName){ 
  //1.得到集合 
  DBCollection coll = db.getCollection(collName); 
  //2.插入操作 
  coll.insert(dbses); 
 } 
 /** 
  * 根据id删除数据 
  * @param id 
  * @param collName 
  * @return 返回影响的数据条数 
  */ 
 public int deleteById(String id,String collName){ 
  //1.得到集合 
  DBCollection coll = db.getCollection(collName); 
  DBObject dbs = new BasicDBObject("_id", new ObjectId(id)); 
  int count = coll.remove(dbs).getN(); 
  return count; 
 } 
 /** 
  * 根据条件删除数据 
  * @param id 
  * @param collName 
  * @return 返回影响的数据条数 
  */  
 public int deleteByDbs(DBObject dbs,String collName){ 
  //1.得到集合 
  DBCollection coll = db.getCollection(collName); 
  int count = coll.remove(dbs).getN(); 
  return count; 
 } 
 /** 
  * 更新数据 
  * @param find 查询器 
  * @param update 更新器 
  * @param upsert 更新或插入 
  * @param multi 是否批量更新 
  * @param collName 集合名称 
  * @return 返回影响的数据条数 
  */ 
 public int update(DBObject find, 
      DBObject update, 
      boolean upsert, 
      boolean multi, 
      String collName){ 
  //1.得到集合 
  DBCollection coll = db.getCollection(collName); 
  int count = coll.update(find, update, upsert, multi).getN(); 
  return count; 
 } 
 /** 
  * 查询器(分页) 
  * @param ref 
  * @param keys 
  * @param start 
  * @param limit 
  * @return 
  */ 
 public DBCursor find(DBObject ref, 
   DBObject keys, 
   int start, 
   int limit, 
   String collName){ 
  DBCursor cur = find(ref, keys, collName); 
  return cur.limit(limit).skip(start); 
 } 
 /** 
  * 查询器(不分页) 
  * @param ref 
  * @param keys 
  * @param start 
  * @param limit 
  * @param collName 
  * @return 
  */ 
 public DBCursor find(DBObject ref, 
   DBObject keys, 
   String collName){ 
  //1.得到集合 
  DBCollection coll = db.getCollection(collName); 
  DBCursor cur = coll.find(ref, keys); 
  return cur; 
 }  
}