Subscribe Consumer<Throwable>
Use the 2nd parameter of subsribe to specify an error handler with Consumer<Throwable>.
Note: If an error handler is not specified, an exception of io.reactivex.exceptions.OnErrorNotImplementedException will be thrown.
Single.fromCallable(new Callable<String>() { @Override public String call() throws Exception { String output = ""; for (int i=0; i<5; i++) { if (i == 2) { throw new Exception("Test"); } output += "Hello " + i + "\n"; } return output; }}).subscribe(new Consumer<String>() { @Override public void accept(String s) throws Exception { Log.d(TAG, s); }}, new Consumer<Throwable>() { @Override public void accept(Throwable throwable) throws Exception { Log.d(TAG, "Error: " + throwable.getMessage()); throwable.printStackTrace(); }});Subscribe Observer
You can subsribe using Observer which include error handling as well.
Observable.create(new ObservableOnSubscribe<String>() { @Override public void subscribe(@NonNull ObservableEmitter<String> emitter) throws Exception { for (int i=0; i<5; i++) { if (i == 2) { throw new Exception("Test"); } emitter.onNext("Hello " + i); } emitter.onComplete(); }}).subscribe(new Observer<String>() { @Override public void onSubscribe(@NonNull Disposable d) { Log.d(TAG, "started"); } @Override public void onNext(@NonNull String s) { Log.d(TAG, s); } @Override public void onError(@NonNull Throwable e) { Log.d(TAG, "Error: " + e.getMessage()); e.printStackTrace(); } @Override public void onComplete() { Log.d(TAG, "ended"); }});Use RxJavaPlugins.setErrorHandler
You can specifiy a global exception handler using RxJavaPlugins.setErrorHandler.
Note: if you already specified an error handler using subscribe, RxJavaPlugins.setErrorHandler will not be called.
// Handle unhandled errorRxJavaPlugins.setErrorHandler(new Consumer<Throwable>() { @Override public void accept(Throwable throwable) throws Exception { Log.e(TAG, throwable.getClass().getName()); // io.reactivex.exceptions.OnErrorNotImplementedException Log.e(TAG, throwable.getCause().getClass().getName()); // java.lang.Exception Log.e(TAG, throwable.getMessage()); // "Test" throwable.printStackTrace(); }});Observable.create(new ObservableOnSubscribe<String>() { @Override public void subscribe(@NonNull ObservableEmitter<String> emitter) throws Exception { for (int i=0; i<5; i++) { if (i == 2) { throw new Exception("Test"); } emitter.onNext("Hello " + i); } emitter.onComplete(); }}).subscribe(new Consumer<String>() { @Override public void accept(String s) throws Exception { Log.d(TAG, s); }});Use doOnError to capture error
doOnError will not handle exception, but it will always be called when an exception happened, no matter the exception is handled or not.
Observable.create(new ObservableOnSubscribe<String>() { @Override public void subscribe(@NonNull ObservableEmitter<String> emitter) throws Exception { for (int i=0; i<5; i++) { if (i == 2) { throw new Exception("Test"); } emitter.onNext("Hello " + i); } emitter.onComplete(); }}).doOnError(new Consumer<Throwable>() { @Override public void accept(Throwable throwable) throws Exception { Log.e(TAG, "Error: " + throwable.getMessage()); throwable.printStackTrace(); }}).subscribe(new Consumer<String>() { @Override public void accept(String s) throws Exception { Log.d(TAG, s); }});