RequestScoped

@RequestScoped
public class RequestScopedClass {
    //This class gets constructed once per Servlet request, and is shared among all CDI-managed classes within that request.

    @Inject
    public RequestScopedClass(SomeDependency someDependency) {
        doSomethingWith(someDependency);
    }

    public RequestScopedClass() {
        //Note that it is required that a request scoped class have a public no-args constructor
    }

}

如果 bean 使用 @RequestScoped 进行注释，则会为任何请求创建一次。如果两个对象依赖于请求范围类，则它们都将获得对同一对象的引用。

注意： 任何请求范围的 bean 必须具有公共的无参数构造函数。其原因将在后面解释。