准备

安装mongodb,并启动，下载mongo-java-driver.jar包。

直接上代码

public static void main(String[] args) throws UnknownHostException {MongoClient client = new MongoClient();DB userdb = client.getDB("test");DBCollection user = userdb.getCollection("user");// 添加System.out.println("--------------添加--------------");BasicDBObject obj = new BasicDBObject();obj.append("name", "you know").append("age", 12).append("job", "singer").append("phone", "1234322234").append("addr", "china");user.insert(obj);System.out.println(obj.getString("_id"));System.out.println("--------------查询--------------");//查询BasicDBObject query = new BasicDBObject();query.append("addr", "china");DBCursor cursor = user.find(query);while (cursor.hasNext()) {DBObject u = cursor.next();System.out.println(u.toString());}//修改System.out.println("--------------修改--------------");BasicDBObject q = new BasicDBObject();//查询条件q.append("phone", "1234322234");BasicDBObject o = new BasicDBObject();//修改内容o.append("job", "java coder");WriteResult r = user.update(q, o);System.out.println(r.toString());//删除System.out.println("--------------删除--------------");WriteResult d = user.remove(q);System.out.println(d.toString());}

看运行结果

--------------添加--------------
570e4624973e75a9365e9640
--------------查询--------------
{ "_id" : { "$oid" : "570e4624973e75a9365e9640"} , "name" : "you know" , "age" : 12 , "job" : "singer" , "phone" : "1234322234" , "addr" : "china"}
--------------修改--------------
{ "serverUsed" : "127.0.0.1:27017" , "ok" : 1 , "n" : 1 , "updatedExisting" : true}
--------------删除--------------
{ "serverUsed" : "127.0.0.1:27017" , "ok" : 1 , "n" : 0}

代码非常简单，可以看到java 对mongo的操作和在shell上操做非常的类似，但因为java语言本身的原因，无法想js等脚本语言那样简洁。

DBObject及其实现类是构建查询对象和保存对象的关键，应该就是构建Bson的关键接口、类。