[英]get nested Object using json-simple - Wildcard for parent Node
I want to retrieve "name" values and store them in an Arraylist from a JSON file in Java. 我想检索“名称”值并将其从Java中的JSON文件存储在Arraylist中。 I am using JSON-simple library Here is an example of my "file.json":
我正在使用JSON简单库这是“ file.json”的示例:
{
"111": {
"customer": {
"name": "John Do",
"Height": 5.9,
"City": "NewYork"
}
},
"222":{
"customer": {
"name": "Sean Williams",
"Height": 6,
"City": "Los Angeles"
}
}
}
Id numbers "111" and "222" are not significant for my program and they are randomly generated so I am not able to use jObject.get()
as the values will constantly be changing. ID号“ 111”和“ 222”对我的程序而言并不重要,它们是随机生成的,因此我无法使用
jObject.get()
因为值将不断变化。 I tried searching for a wildcard for the parent Node and then go to child node customer
and then name
but haven't found such thing. 我尝试搜索父节点的通配符,然后转到子节点
customer
,然后name
但没有找到这样的东西。
Here is my code so far: 到目前为止,这是我的代码:
import java.io.*;
import java.util.ArrayList;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
public class npTest {
public static void main(String[] args) throws IOException, ParseException {
try {
JSONParser jParser = new JSONParser();
JSONObject jObject = (JSONObject) jParser.parse(new FileReader("file.json"));
//Notes
} catch (FileNotFoundException e) {
System.out.print("File not found!");
}
}
} }
Notes: methods I have tried require jObject.get("id")
. 注意:我尝试过的方法需要
jObject.get("id")
。 Also I noticed I am not able to store the JSONObject in another JSONObject, for example: JSONObject parentObj = new JSONObject(jObject.get("111"));
我还注意到我无法将JSONObject存储在另一个JSONObject中,例如:
JSONObject parentObj = new JSONObject(jObject.get("111"));
You can iterate through the keys in a JSONObject
using the keySet()
method. 您可以使用
keySet()
方法遍历JSONObject
的键。 Then pull out your "customer"
and get their name. 然后拉出您的
"customer"
并获得他们的名字。
JSONParser jParser = new JSONParser();
JSONObject jObject = (JSONObject) jParser.parse(new FileReader("c:\\file.json"));
for(Object key : jObject.keySet()) {
JSONObject customerWrapper = (JSONObject)jObject.get(key);
JSONObject customer = (JSONObject)customerWrapper.get("customer");
System.out.println(customer.get("name"));
}
JSONObject implements the Map interface. JSONObject实现Map接口。 So you could query for all map keys with normal Java syntax:
因此,您可以使用常规Java语法查询所有映射键:
for (Object innnerO : jObject.values()){
JSONObject customerO = (JSONObject)((JSONObject)innerO).get("customer");
}
Note: This is written out of my head without compiler. 注意:这是在没有编译器的情况下写出来的。 So there might me errors.
所以可能有我的错误。
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