I am doing a method who return an UUID of a Minecraft player from his username using the Mojang API. This method takes a String in parameter (the username of the player who we want to know the UUID). To use the resultat of the API, I use the SimpleJSON library (to parse the JSON result into a String to return).
My method throws 2 checked exceptions : the IOExeption and the Parseexception, cause I want. When a wrong username (so an username who doesn't exist) the API return a empty JSON object and my method throws an IOException in this case. And this is my problem, when a wrong username is in paramter of the method, the method throw a new IOExcpetion but with a try and catch for the method, the throwing exception isn't catched.
My method :
public static String getUUID(String name) throws IOException, ParseException {
URL url = new URL("https://api.mojang.com/users/profiles/minecraft/" name);
URLConnection uc = url.openConnection();
BufferedReader bf = new BufferedReader(new InputStreamReader(uc.getInputStream()));
StringBuilder response = new StringBuilder();
String inputLine;
while ((inputLine = bf.readLine()) != null) {
response.append(inputLine);
}
bf.close();
if (response.toString().isEmpty()) {
throw new IOException();
}
JSONParser parser = new JSONParser();
Object object = parser.parse(response.toString());
JSONObject jo = (JSONObject) object;
String str = (String) jo.get("id");
return str.replaceAll("(\\w{8})(\\w{4})(\\w{4})(\\w{4})(\\w{12})", "$1-$2-$3-$4-$5");
}
An example of using a valid username :
public static void main(String[] args) {
try {
System.out.println(getUUID("Jeb_"));
} catch (IOException | ParseException e) {
e.printStackTrace();
}
}
And now an example with a wrong username:
public static void main(String[] args) {
try {
System.out.println(getUUID("d"));
} catch (IOException | ParseException e) {
e.printStackTrace();
}
}
Thank you.
CodePudding user response:
Have you verified that your exception might get caught? If it is caught, the code prints a stack trace. But if it is not caught, the JVM will print a stack trace anyway.
So throw the exception with some message you can verify, like
throw new IOException("Invalid user");
and catch the exception by being a bit more verbose:
catch (IOException | ParseException e) {
System.out.println("Could not lookup user " username ", caught " e.getClass().getName() ": " e.getMessage());
}
CodePudding user response:
Actually, your exception is caught, you can check it as follows:
public static void main(String[] args) {
var username = "d";
try {
System.out.println(getUUID(username));
} catch (IOException | ParseException e) {
System.out.println("User " username " not found!");
e.printStackTrace();
}
}
The output of the program will be:
User d not found!
java.io.IOException
at com.company.Main.getUUID(Main.java:37)
at com.company.Main.main(Main.java:17)
This output means that code inside catch block was executed.