如何在Servlet中注入ConversationScoped bean

我需要将一个ConversationScoped bean注入一个servlet.我使用标准的简单@Inject标签,并使用cid参数调用servlet,但是当它调用注入的bean中的任何方法时,我收到以下错误：

org.jboss.weld.context.ContextNotActiveException: WELD-001303 No active contexts for scope type javax.enterprise.context.ConversationScoped

我可以在servlet中注入这些bean,还是只能注入Session和Request scoped bean？

解决方法:

在servlet中,上下文是应用程序上下文,这就是您放松会话范围的原因.
这是一个小实用程序类,您可以将其用作匿名类,如果您希望在servlet中支持对话范围,请将请求包装起来…

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;

import org.jboss.weld.Container;
import org.jboss.weld.context.ContextLifecycle;
import org.jboss.weld.context.ConversationContext;
import org.jboss.weld.servlet.ConversationBeanStore;


public abstract class ConversationalHttpRequest {
    protected HttpServletRequest request;


    public ConversationalHttpRequest(HttpServletRequest request) {
        this.request = request;
    }

    public abstract void process() throws Exception;

    public void run() throws ServletException {
        try {
            initConversationContext();
            process();
        } catch (Exception e) {
            throw new ServletException("Error processing conversational request", e);
        } finally {
            cleanupConversationContext();
        }
    }

    private void initConversationContext() {
        ConversationContext conversationContext = Container.instance().deploymentServices().get(ContextLifecycle.class).getConversationContext();
        conversationContext.setBeanStore(new ConversationBeanStore(request.getSession(), request.getParameter("cid")));
        conversationContext.setActive(true);
    }

    private void cleanupConversationContext() {
        ConversationContext conversationContext = Container.instance().deploymentServices().get(ContextLifecycle.class).getConversationContext();
        conversationContext.setBeanStore(null);
        conversationContext.setActive(false);
    }

}

标签：java,servlets,cdi,jboss-weld
来源： https://codeday.me/bug/20190710/1420734.html