假设你可以分别读取JSON字符串。例如，您读取第一个JSON文本

  {test_id：1245362，name：ganesh，age ：28，Job：
 {company name：company1，designation：SSE} 
} 
 pre> 

并将其分配给变量（String json1），下一步是解析它，
  DBObject dbo =（DBObject）com.mongodb.util.JSON.parse（json1）; 
 
将 dbo 全部放入列表中，
  List< DBObject> list = new ArrayList<>（）; 
 list.add（dbo）; 
 
，然后将它们保存到数据库中：
  new MongoClient（）。getDB（test）。getCollection（collection）。 
 
编辑：
 

在最新的MongoDB您必须使用文档而不是DBObject，并且现在添加对象的方法看起来不同。这是一个更新的示例：
 

导入是：
  import com。 mongodb.MongoClient; 
 import com.mongodb.client.MongoDatabase; 
 import org.bson.Document; 
 
代码会这样（参考EDIT上面的文本）：
 文档doc = Document.parse（json1）; 
 new MongoClient（）。getDataBase（db）。getCollection（collection）。insertOne（doc）; 
 
你也可以用列表的方式。但是你需要
  new MongoClient（）。getDataBase（db）。getCollection（collection）。insertMany ）; 
 
但我认为这个解决方案有一个问题。当您输入：
  db.collection.find（）
 
在mongo shell中获取集合中的所有对象，结果如下所示：
  {_id：ObjectId（56a0d2ddbc7c512984be5d97），
test_id：1245362，name：ganesh，age：28，Job：
 {company name：company1，designation：SSE
} 
} 
 
这和以前不一样。
 
I am struggling with importing data into Mongodb from a Json file.

I can do the same in command line by using mongoimport command.

I explored and tried lot but not able to import from Json file using java.

sample.json
    { "test_id" : 1245362, "name" : "ganesh", "age" : "28", "Job" : 
       {"company name" : "company1", "designation" : "SSE" } 
    }

    { "test_id" : 254152, "name" : "Alex", "age" : "26", "Job" :
       {"company name" : "company2", "designation" : "ML" } 
    }
Thank for your time.
~Ganesh~
Suppose you can read the JSON string respectively. For example, you read the first JSON text
{ "test_id" : 1245362, "name" : "ganesh", "age" : "28", "Job" : 
   {"company name" : "company1", "designation" : "SSE" } 
}
and assign it to a variable (String json1), the next step is to parse it,
DBObject dbo = (DBObject) com.mongodb.util.JSON.parse(json1);
put all dbo into a list,  
List<DBObject> list = new ArrayList<>();
list.add(dbo);
then save them into database:  
new MongoClient().getDB("test").getCollection("collection").insert(list);
EDIT:

In the newest MongoDB Version you have to use Documents instead of DBObject, and the methods for adding the object look different now. Here's an updated example:

Imports are:
import com.mongodb.MongoClient;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;
The code would like this (refering to the text above the EDIT):
Document doc = Document.parse(json1);
new MongoClient().getDataBase("db").getCollection("collection").insertOne(doc);
you can also do it the way with the list. but then you need
new MongoClient().getDataBase("db").getCollection("collection").insertMany(list);
But I think there is a problem with this solution. When you type:
db.collection.find()
in the mongo shell to get all objects in the collection, the result looks like the following:
{ "_id" : ObjectId("56a0d2ddbc7c512984be5d97"),
    "test_id" : 1245362, "name" : "ganesh", "age" : "28", "Job" :
        { "company name" : "company1", "designation" : "SSE" 
    }
}
which is not exactly the same as before.