JSF中的拦截器

我想知道JSF中是否有拦截器（就像我们在Spring中使用的那样），以及如何实现它？

您可以为此实现一个拦截器。您可以对它们进行编程，使其在重写方法中指定的上侦听。您可以通过和方法拦截前后阶段事件

以下示例侦听渲染响应阶段：

public class RequestInterceptor implements PhaseListener {

    @Override
    public PhaseId getPhaseId() {
        return PhaseId.RENDER_RESPONSE;
    }

    @Override
    public void beforePhase(PhaseEvent event) {
        // Do your job here which should run before the render response phase.
    }

    @Override
    public void afterPhase(PhaseEvent event) {
        // Do your job here which should run after the render response phase.
    }

}

要使其运行，您需要在

faces config.xml

文件的

部分将其注册为

。您可以有多个

s

<lifecycle>
    <phase-listener>com.example.RequestInterceptor</phase-listener>
</lifecycle>

或者，如果您想要一个更全局的钩子（因此您对JSF请求/响应不太感兴趣，也不需要来自

FacesContext

的任何内容），则a应该同样有效

---

不太可能有一对一的映射。看一看。

public class PhaseDebugger implements PhaseListener {

    @Override
    public PhaseId getPhaseId() {
        return PhaseId.ANY_PHASE;
    }

    @Override
    public void beforePhase(PhaseEvent event) {
        System.out.println("Before phase " + event.getPhaseId());
    }

    @Override
    public void afterPhase(PhaseEvent event) {
        System.out.println("After phase " + event.getPhaseId());
    }

}

@WebFilter("/*")
public class RequestInterceptor implements Filter {

    @Override
    public void init(FilterConfig config) {
        // Initialize global variables if necessary.
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws ServletException, IOException {
        // Do your job here which should run before the request processing.
        chain.doFilter(request, response);
        // Do your job here which should run after the request processing.
    }

    @Override
    public void destroy() {
        // Cleanup global variables if necessary.
    }

}