SpringBoot学习笔记12 - Interceptor应用

1、定义拦截器

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通过实现接口HandlerInterceptor，并重写其中方法去定义拦截器，接口内容如下：

public interface HandlerInterceptor {
    default boolean preHandle(HttpServletRequest request, HttpServletResponse response,
    						  Object handler) throws Exception {
        return true;
    }

    default void postHandle(HttpServletRequest request, HttpServletResponse response,
    						Object handler, @Nullable ModelAndView modelAndView)
    						throws Exception {
    }

    default void afterCompletion(HttpServletRequest request, HttpServletResponse response,
    							 Object handler, @Nullable Exception ex
    							 ) throws Exception {
    }
}

通过选择性地实现接口HandlerInterceptor中的方法来定义拦截器：

public class FirstInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
                             Object handler) throws Exception {
        System.out.println("执行拦截器[FirstInterceptor], uri: " + request.getRequestURI());
        return true;
    }
}

public class OtherInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
                             Object handler) throws Exception {
        System.out.println("执行拦截器[OtherInterceptor], uri: " + request.getRequestURI());
        return true;
    }
}

2、配置拦截器

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// WebMvcConfigurationSupport充当了原来的Spring配置文件，所以需要使用@Configuration进行注解
@Configuration
public class MyWebMvcConfiguration extends WebMvcConfigurationSupport {
    @Override
    protected void addInterceptors(InterceptorRegistry registry) {
    	// 拦截并处理所有 /intercept/first/ 开头的请求
        registry.addInterceptor(new FirstInterceptor())
                .addPathPatterns("/intercept/first/**");
        // 拦截并处理所有非 /intercept/first/ 开头的请求
        registry.addInterceptor(new OtherInterceptor())
                .excludePathPatterns("/intercept/first/**");
    }
}

3、定义Controller并测试

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@RestController
@RequestMapping("/intercept")
public class DemoController {
    @GetMapping("/first/demo")
    public String firstIntercept() {
        return "First Intercept method";
    }

    @GetMapping("/second/demo")
    public String secondIntercept() {
        return "Second Intercept method";
    }

    @GetMapping("/third/demo")
    public String thirdIntercept() {
        return "Third Intercept method";
    }
}

启动项目并测试：

• addPathPatterns

  

• excludePathPatterns