vaadin-bot
commented
9 years ago Originally by OHaeger
Sorry, my first sample code doesn't show the error - there is no navigator inside. Here is a new one (with a workaround)
import javax.servlet.annotation.WebServlet;
import com.vaadin.annotations.Theme;
import com.vaadin.annotations.VaadinServletConfiguration;
import com.vaadin.event.SelectionEvent;
import com.vaadin.event.SelectionEvent.SelectionListener;
import com.vaadin.navigator.Navigator;
import com.vaadin.navigator.View;
import com.vaadin.navigator.ViewChangeListener.ViewChangeEvent;
import com.vaadin.server.VaadinRequest;
import com.vaadin.server.VaadinServlet;
import com.vaadin.ui.Button;
import com.vaadin.ui.Button.ClickEvent;
import com.vaadin.ui.Button.ClickListener;
import com.vaadin.ui.Grid;
import com.vaadin.ui.UI;
import com.vaadin.ui.VerticalLayout;
@Theme("mytheme")
@SuppressWarnings("serial")
public class MyVaadinUI extends UI {
@WebServlet(value # "/*", asyncSupportedtrue)
@VaadinServletConfiguration(productionMode # false, uiMyVaadinUI.class, widgetset = "com.vaadin.gridtest.AppWidgetSet")
public static class Servlet extends VaadinServlet {
}
@Override
protected void init(VaadinRequest request) {
Navigator navigator = new Navigator(this, this);
navigator.addView("", new FirstView());
navigator.addView("SecondView", new SecondView());
}
private class FirstView extends VerticalLayout implements View {
public FirstView() {
setMargin(true);
Grid grid = new Grid();
// Define some columns
grid.addColumn("name", String.class);
grid.addColumn("born", Integer.class);
// Add some data rows
grid.addRow("Nicolaus Copernicus", 1543);
grid.addRow("Galileo Galilei", 1564);
grid.addRow("Johannes Kepler", 1571);
addComponent(grid);
grid.addSelectionListener(new SelectionListener() {
@Override
public void select(SelectionEvent event) {
getUI().getNavigator().navigateTo("SecondView"); _ throws NullPointerException
_ Workaround_ getUI().access(new Runnable() {
_ @Override_ public void run() {
_ getUI().getNavigator().navigateTo("SecondView");_ }
_ });
}
});
}
@Override
public void enter(ViewChangeEvent event) {
// TODO Auto-generated method stub
}
}
private class SecondView extends VerticalLayout implements View {
public SecondView() {
addComponent(new Button("Back to Main View", new ClickListener() {
@Override
public void buttonClick(ClickEvent event) {
getUI().getNavigator().navigateTo("");
}
}));
}
@Override
public void enter(ViewChangeEvent event) {
// TODO Auto-generated method stub
}
}
}And this is the correct stacktrace:
Schwerwiegend:
java.lang.NullPointerException
at com.vaadin.ui.Grid$3.select(Grid.java:3031)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:168)
at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:118)
at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:291)
at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:184)
at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:92)
at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1408)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:350)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:684)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:503)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:137)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:557)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:231)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1086)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:429)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:193)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1020)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:255)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:154)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
at org.eclipse.jetty.server.Server.handle(Server.java:370)
at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:494)
at org.eclipse.jetty.server.AbstractHttpConnection.content(AbstractHttpConnection.java:982)
at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.content(AbstractHttpConnection.java:1043)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:865)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:240)
at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:696)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:53)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:608)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543)
at java.lang.Thread.run(Thread.java:744)
stale[bot]
Originally by OHaeger
By calling the navigateTo function inside a grid selection listener vaadin throws a NullPointerExecption.
Exception is:
Imported from https://dev.vaadin.com/ issue #17722