Vaadin 8设置会话超时

Question

How to set timeout of a session in Vaadin 8?

I am not using web.xml, which has been the place to set it in prior versions of the framework.

Answer 1

Session timeout is set in web.xml.

If you don't have one, then you will need to create one.

How do i set session timeout in seconds in web.xml?

As you seem to use spring boot, then this might apply to you

Spring Boot Java Config Set Session Timeout

Answer 2

tl;dr

You can set the standard Servlet session's timeout as a int number of whole seconds, after extracting from the wrapping VaadinSession .

VaadinSession.getCurrent().getSession().setMaxInactiveInterval ( ( int ) TimeUnit.MINUTES.toSeconds( 30 ) ) ;

Set session timeout programmatically

Setting the session timeout is a feature in your web container , your Servlet engine, such as Tomcat, Jetty, etc. The Servlet spec defines this behavior for Java apps as part of its session handling.

Vaadin wraps the Servlet session inside a VaadinSession . So extract the regular Servlet session from Vaadin as a WrappedSession , then call the setMaxInactiveInterval method to set the time to expire.

Specify the time limit as a number of whole seconds. The TimeUnit enum is handy to calculate the seconds without resorting to “magic” numbers .

VaadinSession               // Wraps a standard Servlet session.
.getCurrent()               // Access the current user’s session.
.getSession()               // Access the wrapped standard Servlet session.
.setMaxInactiveInterval(    // Set the timeout.
    ( int )                 // Cast a `long` to an `int`.
    TimeUnit                // The `TimeUnit` enum is more self-documenting than using a literal integer number.
    .MINUTES                // Here we set a half hour, 30 minutes.
    .toSeconds( 30 )        // Set a number of whole seconds.      
)
;

Here is a complete example Vaadin 8.5 app created from the Maven archetype vaadin-archetype-application . We added a single line to the beginning of the init method.

package com.basilbourque.example;

import javax.servlet.annotation.WebServlet;

import com.vaadin.annotations.Theme;
import com.vaadin.annotations.VaadinServletConfiguration;
import com.vaadin.server.VaadinRequest;
import com.vaadin.server.VaadinServlet;
import com.vaadin.server.VaadinSession;
import com.vaadin.ui.Button;
import com.vaadin.ui.Label;
import com.vaadin.ui.TextField;
import com.vaadin.ui.UI;
import com.vaadin.ui.VerticalLayout;

import java.util.concurrent.TimeUnit;

/**
 * This UI is the application entry point. A UI may either represent a browser window
 * (or tab) or some part of an HTML page where a Vaadin application is embedded.
 * <p>
 * The UI is initialized using {@link #init(VaadinRequest)}. This method is intended to be
 * overridden to add component to the user interface and initialize non-component functionality.
 */
@Theme ( "mytheme" )
public class MyUI extends UI {

    @Override
    protected void init ( VaadinRequest vaadinRequest ) {
        // Set Session timeout programmatically. Overrides the default timeout configured for Servlet.
        VaadinSession.getCurrent().getSession().setMaxInactiveInterval( ( int ) TimeUnit.MINUTES.toSeconds( 45 ) );  // Setting timeout of 45 minutes = ( 45 * 60 ) seconds.

        final VerticalLayout layout = new VerticalLayout();

        final TextField name = new TextField();
        name.setCaption( "Type your name here:" );

        Button button = new Button( "Click Me" );
        button.addClickListener( e -> {
            layout.addComponent( new Label( "Thanks " + name.getValue()
                                                + ", it works!" ) );
        } );

        layout.addComponents( name , button );

        setContent( layout );
    }

    @WebServlet ( urlPatterns = "/*",
        name = "MyUIServlet",
        asyncSupported = true )
    @VaadinServletConfiguration ( ui = MyUI.class,
        productionMode = false )
    public static class MyUIServlet extends VaadinServlet {
    }
}

Servlet, not Vaadin

I am not using web.xml, which has been the place to set it in prior versions of the framework.

Actually, the session timeout is a Servlet thing, not a Vaadin-specific thing. And the web.xml is a Servlet thing, not a Vaadin-specific thing.

See:

• javax.servlet.http.HttpSession::setMaxInactiveInterval(int interval) method
• Servlet 3.1 specification (a PDF document)
• Servlet 4 specification

Further discussed in How to set session timeout dynamically in Java web applications? .