java - 如何在 Servlet 中注入(inject) ConversationScoped bean

Question

我需要将 ConversationScoped bean 注入(inject)到 servlet 中。我使用标准的简单 @Inject 标记，并使用 cid 参数调用 servlet，但是当它调用注入(inject) 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(inject)这些 bean 还是只能注入(inject) Session 和 Request 作用域的 bean？

Answer 1

在 servlet 中，上下文是应用程序上下文，这就是您放宽对话范围的原因。这是一个小型实用程序类，如果您希望在 servlet 中支持对话范围，您可以将其用作匿名类并包装请求...

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);
    }

}