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Java Fetch
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| import java.io.BufferedReader; | |
| import java.io.IOException; | |
| import java.io.InputStreamReader; | |
| import java.net.MalformedURLException; | |
| import java.net.URL; | |
| import java.net.URLConnection; | |
| import java.nio.charset.StandardCharsets; | |
| import java.util.concurrent.*; | |
| import java.util.function.Consumer; | |
| public class Fetch<T> extends Thread { | |
| private Callable<T> task; | |
| private Consumer<Exception> fail; | |
| private Consumer<T> then; | |
| private URL url; | |
| public Fetch(String url) { | |
| try { | |
| this.url = new URL(url); | |
| this.task = () -> (T)getPage(url); | |
| } catch (MalformedURLException e) { | |
| e.printStackTrace(); | |
| } | |
| } | |
| public Fetch(Callable<T> task) { | |
| this.task = task; | |
| } | |
| public Fetch<T> then(Consumer<T> task) { | |
| then = task; | |
| return this; | |
| } | |
| public Fetch<T> fail(Consumer<Exception> task) { | |
| fail = task; | |
| return this; | |
| } | |
| public Thread get() { | |
| Thread thread = new Thread(this::execute); | |
| thread.start(); | |
| return thread; | |
| } | |
| private void execute() { | |
| ExecutorService executor = Executors.newSingleThreadExecutor(); | |
| Future<T> result = executor.submit(task); | |
| while (!result.isDone()) { | |
| } | |
| try { | |
| T actualResult = result.get(); | |
| if (then != null) then.accept(actualResult); | |
| } catch (InterruptedException | ExecutionException e) { | |
| fail.accept(e); | |
| } | |
| } | |
| private String getPage(String url) { | |
| try { | |
| URLConnection connection = new URL(url).openConnection(); | |
| connection.setRequestProperty("User-Agent", | |
| "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.95 Safari/537.11"); | |
| connection.connect(); | |
| BufferedReader r = new BufferedReader(new InputStreamReader(connection.getInputStream(), StandardCharsets.UTF_8)); | |
| StringBuilder sb = new StringBuilder(); | |
| String line; | |
| while ((line = r.readLine()) != null) { | |
| sb.append(line); | |
| } | |
| return sb.toString(); | |
| } catch (IOException e) { | |
| e.printStackTrace(); | |
| } | |
| return null; | |
| } | |
| } |
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| public class Main { | |
| public static void main(String[] args) { | |
| // URL example | |
| new Fetch<>("https://www.google.com/") | |
| .then(System.out::println) // print the content of the webpage | |
| .fail(Throwable::printStackTrace) // print stacktrace on a failure | |
| .get(); // actually fetch the data | |
| // Function example | |
| // Provide the DataType that the function returns | |
| new Fetch<AbstractPack>(() -> PackHub.api().getPackFromId(0)) | |
| // function to convert String into an AbstractPack (JSON string -> AbstractPack) | |
| .then(result -> { | |
| // print result.getName() if isValid() is true, otherwise print the error. | |
| System.out.println(result.isValid() ? result.getName() : result.getError()); | |
| }).fail(exception -> { | |
| exception.printStackTrace(); // print stacktrace on failure | |
| }).get(); // fetch data | |
| } | |
| } |
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