Mongo Java：如何在文件中将DBObject序列化为JSON？

Question

I have a document in MongoDB as

name: name
date_created: date
p_vars: {
   01: {
      a: a,
      b: b,
   }
   02: {
      a: a,
      b: b,
   }
   ....
}

represented as DBObject

• All key , value pairs are of type String
• I want to serialize this document using Java, Looking at the api , I did not find anything, How can I serialize a DBObject as JSON on file?

Answer 1

似乎BasicDBObject的toString（）方法返回对象的JSON序列化。

Answer 2

看起来JSON类有一个方法将对象序列化为JSON（以及另一种方式并解析JSON以检索DBObject）。

Answer 3

I used the combination of BasicDBObject's toString() and GSON library in the order to get pretty-printed JSON:

    com.mongodb.DBObject obj = new com.mongodb.BasicDBObject();
    obj.put("_id", ObjectId.get());
    obj.put("name", "name");
    obj.put("code", "code");
    obj.put("createdAt", new Date());

    com.google.gson.Gson gson = new com.google.gson.GsonBuilder().setPrettyPrinting().create();

    System.out.println(gson.toJson(gson.fromJson(obj.toString(), Map.class)));