SpringBoot使用Interceptor拦截器的实例
在springboot中使用拦截器也比较简单,实现HandlerInterceptor或者AsyncHandlerInterceptor接口,再从配置里添加一下拦截器就完成了;
AsyncHandlerInterceptor接口继承了HandlerInterceptor,多了一个afterConcurrentHandlingStarted方法:
接口里的方法:
- preHandle:在Controller之前执行,可以判断参数,执行的controller方法等,返回值为boolean,返回true继续往下运行(下面的拦截器和controller),否则开始返回操作(执行之前的拦截器返回等操作);
- postHandle:在Controller之后,视图返回前执行,可对ModelAndView进行处理再返回;
- after编程客栈Completion:请求完成后执行;
- afterConcurrentHandlingStarted:controller返回值是Java.util.concurrent.Callable时才会调用该方法并使用新线程运行;
方法执行顺序有两种:
- preHandle -> 执行Controller -> postHandle -> afterCompletion;
- preHandle -> 执行Controller -> afterConcurrentHandlingStarted -> callable线程执行call()方法 -> 新线程开始preHandle -> postHandle -> afterCompletion;(controllphper方法返回Callable对象时)
配置拦截器:
实现WebMvcConfigurer接口里的addInterceptors方法,使用参数InterceptorRegistry对象添加自己的拦截器,可以添加指定拦截路径或者去掉某些过滤路径,还可以设置拦截器的优先级order,优先级由小到大,默认0;
多个拦截器的执行顺序:
preHandle方法按照order由小到大顺序,执行完controller后,其他方法则反向顺序,跟过滤器Filter类似;
测试启动类,默认配置:
/** * 2023年3月16日下午4:56:23 */ package testspringboot.test9interceptor; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; /** * @author XWF * */ @SpringBootApplication public class Test9Main { /** * @param args */ public static void main(String[] args) { SpringApplication.run(Test9Main.class, args); } }
controller类:
/** * 2023年3月16日下午4:58:02 */ package testspringboot.test9interceptor; import java.util.concurrent.Callable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestControll开发者_JAVA开发er; /** * @author XWF * */ @RestController @RequestMapping("/interceptor") public class Test9Controller { @RequestMapping("/a") public String a(String s) { System.out.println(">>>a():" + s); return "OK"; } @RequestMapping("/b") public Callable<String> b() { Callable<String> callable = new Callable<String>() { @Override public String call() throws Exception { Thread.sleep(2000); System.out.println("call() thread id=" +编程客栈 Thread.currentThread().getId()); Thread.sleep(2000); return "abcdefg"; } }; System.out.println(">>>b()"); return callable; } }
两个自定义拦截器1和2:
/** * 2023年3月16日下午5:14:14 */ package testspringboot.test9interceptor; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAn编程dView; /** * @author XWF * */ public class MyInterceptor1 implements HandlerInterceptor { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object h编程客栈andler) throws Exception { System.out.println("preHandle 1, handler=" + handler); return request.getQueryString().length() < 10 ? true : false; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println("postHandle 1"); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println("afterCompletion 1"); } }
/** * 2023年3月16日下午5:15:28 */ package testspringboot.test9interceptor; import java.util.Date; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.stereotype.Component; import org.springframework.web.servlet.AsyncHandlerInterceptor; import org.springframework.web.servlet.ModelAndView; /** * @author XWF * */ @Component public class MyInterceptor2 implements AsyncHandlerInterceptor { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println("preHandle 2 " + new Date() + " ThreadId=" + Thread.currentThread().getId()); return true; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println("postHandle 2"); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println("afterCompletion 2"); } @Override public void afterConcurrentHandlingStarted(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println("afterConcurrentHandlingStarted 2 " + new Date()); } }
配置拦截器:
/** * 2023年3月16日下午5:20:31 */ package testspringboot.test9interceptor; import javax.annotation.Resource; import org.springframework.context.annotation.Configuration; import org.springframework.web.servlet.config.annotation.InterceptorRegistry; import org.springframework.web.servlet.config.annotation.WebMvcConfigurer; /** * @author XWF * */ @Configuration public class MyInterceptorConfig implements WebMvcConfigurer { @Resource MyInterceptor2 myinterceptor2; @Override public void addInterceptors(InterceptorRegistry registry) { registry.addInterceptor(new MyInterceptor1()) .addPathPatterns("/interceptor/a") //添加拦截路径,两种参数List<String>和String ... .excludePathPatterns("/interceptor/b") //排除路径,两种参数List<String>和String ... .order(1); //设置拦截器顺序,由小到大,默认0 registry.addInterceptor(myinterceptor2); //也可以使用spring管理的对象 } }
发送一个post测试请求:http://192.168.1.30:8080/interceptor/a?s=hello,拦截器2的order默认0,拦截器1的order为1,preHandle先执行2的,controller执行之后,剩下的Handle都是先执行1再执行2的;
发送preHandle返回false的请求:http://192.168.1.30:8080/interceptor/a?s=hello123456789,拦截器1的preHandle返回false后,直接执行2的afterCompletion;
发送测试callable的请求:http://192.168.1.30:8080/interceptor/b?s=hello,拦截路径配置跳过拦截器1只执行拦截器2,通过threadid可以看到前后使用的是两个线程;
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