Java中来自数据库的Json对象 [英] Json object from database in java

问题描述

有人可以帮助我如何从数据库创建JSON对象吗?

Can anyone help me how to create a JSON Object from the database?

JSON输出应如下所示:

{"devicelist":{
    "device": [
    {"id": "01", "type": "CAM", "name": "Livingroom"}
    {"id": "15", "type": "CAM", "name": "Kitchen"}
]
}}

这是我的代码:

 if (reg!=null)
 {

     try
                  {
                     con = ds.getConnection();
                     Statement select = con.createStatement();
                    ResultSet result=select.executeQuery("Select type,name,demo from register_device");  
                      while (result.next())
                      {
                         String  type_json=result.getString("type");
                         String name_json=result.getString("name");
                         String id_json=result.getString("demo");
                         JSONArray arrayObj=new JSONArray();

                      }
                  }
                  catch(Exception e)
                  {

                  }
      }

我能够从数据库中获取选定的类型，名称，演示.

I am able to get the selected type,name,demo from the database.

我不知道如何开始JSON编码.

I don't know how to start the JSON coding.

推荐答案

如果您想从数据库中提取数据并自己构造JSON对象，则可以执行以下操作:

If you want to extract the data from the DB and construct the JSON Object yourself, you can do:

JsonArray jArray = new JsonArray();
while (result.next())
{
    String  type_json=result.getString("type");
    String name_json=result.getString("name");
    String id_json=result.getString("demo");
    JsonObject jObj = new JsonObject();
    jobj.put("id", id_json);
    jobj.put("type", type_json);
    jobj.put("name", name_json);
    jArray.put(jObj);
}

JsonObject jObjDevice = new JsonObject();
jObjDevice.put("device", jArray);
JsonObject jObjDeviceList = new JsonObject();
jObjDevice.put("devicelist", jObjDevice );

现在jObjDeviceList包含所有数据.

这篇关于Java中来自数据库的Json对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！