vaadin-framework/uitest/src/main/java/com/vaadin/tests/components/ui/UIAccessExceptionHandling.java

package com.vaadin.tests.components.ui;

import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;

import com.vaadin.server.DefaultErrorHandler;
import com.vaadin.server.ErrorHandler;
import com.vaadin.server.ErrorHandlingRunnable;
import com.vaadin.server.VaadinRequest;
import com.vaadin.server.VaadinService;
import com.vaadin.tests.components.AbstractTestUIWithLog;
import com.vaadin.ui.Button;
import com.vaadin.ui.UI;
import com.vaadin.util.CurrentInstance;

public class UIAccessExceptionHandling extends AbstractTestUIWithLog
        implements ErrorHandler {

    private Future<Void> future;

    @Override
    protected void setup(VaadinRequest request) {
        getSession().setErrorHandler(this);

        addComponent(
                new Button("Throw RuntimeException on UI.access", event -> {
                    log.clear();

                    // Ensure beforeClientResponse is invoked
                    markAsDirty();

                    future = access(() -> {
                        throw new RuntimeException();
                    });
                }));

        addComponent(new Button("Throw RuntimeException on Session.access",
                event -> {
                    log.clear();

                    // Ensure beforeClientResponse is invoked
                    markAsDirty();

                    VaadinService service = VaadinService.getCurrent();

                    future = service.accessSession(getSession(), () -> {
                        throw new RuntimeException();
                    });
                }));

        addComponent(new Button(
                "Throw RuntimeException after removing instances", event -> {
                    log.clear();

                    // Ensure beforeClientResponse is invoked
                    markAsDirty();

                    assert UI.getCurrent() == UIAccessExceptionHandling.this;

                    Map<Class<?>, CurrentInstance> instances = CurrentInstance
                            .getInstances();
                    CurrentInstance.clearAll();

                    assert UI.getCurrent() == null;

                    future = access(() -> {
                        throw new RuntimeException();
                    });

                    CurrentInstance.restoreInstances(instances);
                }));

        addComponent(
                new Button("Throw through ErrorHandlingRunnable", event -> {
                    access(new ErrorHandlingRunnable() {
                        @Override
                        public void run() {
                            log.clear();
                            throw new NullPointerException();
                        }

                        @Override
                        public void handleError(Exception exception) {
                            // "Handle" other exceptions, but leave NPE for
                            // default handler
                            if (exception instanceof NullPointerException) {
                                NullPointerException npe = (NullPointerException) exception;
                                throw npe;
                            }
                        }
                    });
                }));

        addComponent(new Button("Clear", event -> log.clear()));
    }

    @Override
    public void beforeClientResponse(boolean initial) {
        if (future != null) {
            try {
                future.get();
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (ExecutionException e) {
                log("Exception caught on get: " + e.getClass().getName());
            } finally {
                future = null;
            }
        }
    }

    @Override
    public void error(com.vaadin.server.ErrorEvent event) {
        log("Exception caught on execution with "
                + event.getClass().getSimpleName() + " : "
                + event.getThrowable().getClass().getName());

        DefaultErrorHandler.doDefault(event);
    }

    @Override
    protected String getTestDescription() {
        return "Test for handling exceptions in UI.access and Session.access";
    }

    @Override
    protected Integer getTicketNumber() {
        return Integer.valueOf(12703);
    }

}