Spring MVC 多个拦截器的执行顺序

Spring MVC支持配置多个拦截器，它们的执行顺序遵循特定规则，理解这些规则对正确设计拦截链至关重要。

注册顺序决定执行顺序

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // 按注册顺序配置拦截器
        registry.addInterceptor(interceptorA)
            .addPathPatterns("/**");

        registry.addInterceptor(interceptorB)
            .addPathPatterns("/**");

        registry.addInterceptor(interceptorC)
            .addPathPatterns("/**");
    }
}

执行顺序规则

请求进入
    ↓
preHandle(A) → preHandle(B) → preHandle(C)   【顺序执行】
    ↓
Controller处理
    ↓
postHandle(C) → postHandle(B) → postHandle(A) 【逆序执行】
    ↓
视图渲染
    ↓
afterCompletion(C) → afterCompletion(B) → afterCompletion(A) 【逆序执行】

执行流程图解

Interceptor A   Interceptor B   Interceptor C
    ↓               ↓               ↓
preHandle(A) ─→ preHandle(B) ─→ preHandle(C)
                                    ↓
                                Controller
                                    ↓
postHandle(C) ←─ postHandle(B) ←─ postHandle(A)
                                    ↓
                                View渲染
                                    ↓
afterCompletion(C)←─ afterCompletion(B)←─ afterCompletion(A)
                                    ↓
                                响应完成

代码验证示例

@Component
public class InterceptorA implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request,
                            HttpServletResponse response,
                            Object handler) {
        log.info("InterceptorA - preHandle");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request,
                           HttpServletResponse response,
                           Object handler,
                           ModelAndView modelAndView) {
        log.info("InterceptorA - postHandle");
    }

    @Override
    public void afterCompletion(HttpServletRequest request,
                                HttpServletResponse response,
                                Object handler,
                                Exception ex) {
        log.info("InterceptorA - afterCompletion");
    }
}

@Component
public class InterceptorB implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request,
                            HttpServletResponse response,
                            Object handler) {
        log.info("InterceptorB - preHandle");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request,
                           HttpServletResponse response,
                           Object handler,
                           ModelAndView modelAndView) {
        log.info("InterceptorB - postHandle");
    }

    @Override
    public void afterCompletion(HttpServletRequest request,
                                HttpServletResponse response,
                                Object handler,
                                Exception ex) {
        log.info("InterceptorB - afterCompletion");
    }
}

执行日志输出：

InterceptorA - preHandle
InterceptorB - preHandle
InterceptorC - preHandle
Controller处理...
InterceptorC - postHandle
InterceptorB - postHandle
InterceptorA - postHandle
InterceptorC - afterCompletion
InterceptorB - afterCompletion
InterceptorA - afterCompletion

preHandle返回false的影响

当某个拦截器的preHandle返回false时，后续拦截器不再执行：

@Override
public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(interceptorA)
        .addPathPatterns("/**");

    registry.addInterceptor(interceptorB)
        .addPathPatterns("/**");
}

如果InterceptorA的preHandle返回false：

preHandle(A) → 返回false，请求被拦截
    ↓
后续拦截器B的preHandle不执行
    ↓
Controller不执行
    ↓
所有postHandle不执行
    ↓
afterCompletion(A)执行（已执行preHandle的拦截器）
    ↓
InterceptorB的afterCompletion不执行

order()方法控制顺序

@Override
public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(interceptorA)
        .addPathPatterns("/**")
        .order(3);    // order值越大，优先级越低

    registry.addInterceptor(interceptorB)
        .addPathPatterns("/**")
        .order(1);    // order值越小，优先级越高

    registry.addInterceptor(interceptorC)
        .addPathPatterns("/**")
        .order(2);
}

使用order后的执行顺序：

preHandle: B(order=1) → C(order=2) → A(order=3)
postHandle: A(order=3) → C(order=2) → B(order=1)
afterCompletion: A(order=3) → C(order=2) → B(order=1)

order值越小的拦截器，preHandle越先执行，postHandle和afterCompletion越后执行。

实际应用场景

@Override
public void addInterceptors(InterceptorRegistry registry) {
    // 1. 性能监控拦截器 - 最先执行（order最小）
    registry.addInterceptor(performanceInterceptor())
        .addPathPatterns("/**")
        .order(1);

    // 2. 日志记录拦截器
    registry.addInterceptor(logInterceptor())
        .addPathPatterns("/**")
        .order(2);

    // 3. 认证拦截器
    registry.addInterceptor(authInterceptor())
        .addPathPatterns("/api/**")
        .order(3);

    // 4. 权限拦截器 - 在认证之后执行
    registry.addInterceptor(permissionInterceptor())
        .addPathPatterns("/api/**")
        .order(4);
}

异常情况下的执行顺序

当Controller抛出异常时：

preHandle(A) → preHandle(B) → preHandle(C)  正常执行
    ↓
Controller抛出异常
    ↓
postHandle均不执行
    ↓
afterCompletion(C) → afterCompletion(B) → afterCompletion(A)  正常执行（逆序）

Controller异常时postHandle不执行，但afterCompletion仍会正常执行（逆序）。

要点总结

• preHandle按注册顺序执行（先注册先执行）
• postHandle和afterCompletion逆序执行（后注册先执行）
• preHandle返回false会中断后续拦截器执行
• order()方法可显式控制执行顺序，值越小优先级越高
• Controller异常时postHandle不执行，afterCompletion仍执行