ClassCastException：org.json.simple.JSONArray无法转换为org.json.simple.JSONObject

Question

I am trying to parse a son file, and I don't know what I'm doing wrong (of course, I don't really know what I'm doing right, either).

file.json

[{  
"arrOne":{  
    "one":"a",
    "two":"b",
    "three":"c",
    "four":"d",
    "five":"e"
},
"elemTwo":"f",
"elemThree":"g",
"elemFour":"h",
"elemFive":"i",
"arrSix":[{  
    "six":1,
    "seven":2,
    "eight":"j"
}]}]

code:

import java.io.FileNotFoundException;
import java.io.FileReader;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
//...........
JSONParser parser = new JSONParser();
Object obj = parser.parse(new FileReader("/path/to/file.json"));
JSONObject json = (JSONObject) obj;
String unit = (String) json.get("elemTwo");
System.out.println(unit);

I get the error ClassCastException: org.json.simple.JSONArray cannot be cast to org.json.simple.JSONObject. Truthfully, I have no idea what I'm doing. Any help would be great! Thanks!

Answer 1

您应该将obj JsonArray为JsonArray而不是JsonObject ，因为您的json文件的根目录为[] 。

Answer 2

you are getting JSONArray not JsonObject

JSONParser parser = new JSONParser();
Object obj = parser.parse(new FileReader("/path/to/file.json"));
JSONArray json = (JSONArray) obj;

Than loop this and get jsonobject

Answer 3

When the JSonParser parses the file, it's returning it as a JSONArray , to solve it try to use this:

    JSONObject obj = (JSONObject)obj;
    JSONObject elem = (JSONObject)obj.get("0");
    String unit = (String) elem.get("elemTwo");
    System.out.println(unit);