Examples with RxJavaObservableExecutionHook rx.plugins.RxJavaObservableExecutionHook used on opensource projects

Example 1 with RxJavaObservableExecutionHook

use of rx.plugins.RxJavaObservableExecutionHook in project ratpack by ratpack.

the class RxRatpack method initialize.

/**
   * Registers an {@link RxJavaObservableExecutionHook} with RxJava that provides a default error handling strategy of forwarding exceptions to the execution error handler.
   * <p>
   * This method is idempotent.
   * It only needs to be called once per JVM, regardless of how many Ratpack applications are running within the JVM.
   * <p>
   * For a Java application, a convenient place to call this is in the handler factory implementation.
   * <pre class="java">{@code
   * import ratpack.error.ServerErrorHandler;
   * import ratpack.rx.RxRatpack;
   * import ratpack.test.embed.EmbeddedApp;
   * import rx.Observable;
   * import static org.junit.Assert.assertEquals;
   *
   * public class Example {
   *   public static void main(String... args) throws Exception {
   *     RxRatpack.initialize(); // must be called once for the life of the JVM
   *
   *     EmbeddedApp.fromHandlers(chain -> chain
   *       .register(s -> s
   *         .add(ServerErrorHandler.class, (ctx, throwable) ->
   *           ctx.render("caught by error handler: " + throwable.getMessage())
   *         )
   *       )
   *       .get(ctx -> Observable.<String>error(new Exception("!")).subscribe(ctx::render))
   *     ).test(httpClient ->
   *       assertEquals("caught by error handler: !", httpClient.getText())
   *     );
   *   }
   * }
   * }</pre>
   */
@SuppressWarnings("deprecation")
public static void initialize() {
    RxJavaPlugins plugins = RxJavaPlugins.getInstance();
    ExecutionHook ourHook = new ExecutionHook();
    try {
        plugins.registerObservableExecutionHook(ourHook);
    } catch (IllegalStateException e) {
        RxJavaObservableExecutionHook existingHook = plugins.getObservableExecutionHook();
        if (!(existingHook instanceof ExecutionHook)) {
            throw new IllegalStateException("Cannot install RxJava integration because another execution hook (" + existingHook.getClass() + ") is already installed");
        }
    }
    ErrorHandler ourErrorHandler = new ErrorHandler();
    try {
        plugins.registerErrorHandler(ourErrorHandler);
    } catch (IllegalStateException e) {
        RxJavaErrorHandler existingErrorHandler = plugins.getErrorHandler();
        if (!(existingErrorHandler instanceof ErrorHandler)) {
            throw new IllegalStateException("Cannot install RxJava integration because another error handler (" + existingErrorHandler.getClass() + ") is already installed");
        }
    }
    try {
        plugins.registerSchedulersHook(new DefaultSchedulers());
    } catch (IllegalStateException e) {
        rx.plugins.RxJavaSchedulersHook existingSchedulers = plugins.getSchedulersHook();
        if (!(existingSchedulers instanceof DefaultSchedulers)) {
            throw new IllegalStateException("Cannot install RxJava integration because another set of default schedulers (" + existingSchedulers.getClass() + ") is already installed");
        }
    }
}