I have a Java String that contains a json object and I do not know how to get this json object from it?
My string is like this:
String myString = "[1,\"{\\\"Status\\\":0,\\\"InstanceNumber\\\":9}\"]";
How can i get the json object from this String?
I would recommend simple plain org.json library. Pass the string in JSONArray and then get the JSONObject. For example something like below :
String myString = "[1,\"{\\\"Status\\\":0,\\\"InstanceNumber\\\":9}\"]";
JSONArray js = new JSONArray(myString);
System.out.println(js);
JSONObject obj = new JSONObject(js.getString(1));
System.out.println(obj);
Output :
- [1,"{\"Status\":0,\"InstanceNumber\":9}"]
- {"Status":0,"InstanceNumber":9}
Downloadable jar: http://mvnrepository.com/artifact/org.json/json
For sure that you need to use a library lie Jackson or Gson.
I work mostly with gson when I don't have complicated stuff. So here the output of what you are asking for. I suppose that you don't have the type that you want to convert to (for that I am taking Object).
Here is the code:
import com.google.gson.Gson;
public class Json {
public static void main(String[] args) {
Gson g = new Gson();
String myString = "[1,\"{\\\"Status\\\":0,\\\"InstanceNumber\\\":9}\"]";
Object p = g.fromJson(myString, Object.class);
System.out.println(p.toString());
}
}
And here is the output :
run:
[1.0, {"Status":0,"InstanceNumber":9}]
BUILD SUCCESSFUL (total time: 0 seconds)
You may wanting to manipulate the output object as you wish (I just printed it out). NOTE: Don't forget to add gson jar to you classpath.
You can use any Json mapping framework to deserialise the String into Java object. Below example shows how to do it with Jackson:
String myString = "[1,\"{\\\"Status\\\":0,\\\"InstanceNumber\\\":9}\"]";
ObjectMapper mapper = new ObjectMapper();
List<Object> value = mapper.readValue(myString, new TypeReference<List<Object>>() {});
Map<String, Object> map = mapper.readValue(value.get(1).toString(), new TypeReference<Map<String, Object>>() {});
System.out.println(map);
Here's the documentation.
