在springboot中使用攔截器也比較簡單,實現HandlerInterceptor或者AsyncHandlerInterceptor接口,再從配置裡添加一下攔截器就完成了;
AsyncHandlerInterceptor接口繼承了HandlerInterceptor,多了一個afterConcurrentHandlingStarted方法:
介面裡的方法:
preHandle:在Controller之前執行,可以判斷參數,執行的controller方法等,返回值為boolean,返回true繼續往下運行(下面的攔截器和controller),否則開始返回操作(執行之前的攔截器返回等操作);
postHandle:在Controller之後,視圖返回前執行,可對ModelAndView進行處理再返回;
afterCompletion:請求完成後執行;
#afterConcurrentHandlingStarted:controller回傳值是java.util.concurrent.Callable時才會呼叫該方法並使用新執行緒執行;
方法執行順序有兩種:
preHandle -> 執行Controller -> postHandle -> afterCompletion;
preHandle -> 執行Controller -> afterConcurrentHandlingStarted -> callable執行緒執行call()方法-> 新執行緒開始preHandle -> postHandle -> afterCompletion;(controller方法回傳Callable物件時)
#設定攔截器:
實作WebMvcConfigurer介面裡的addInterceptors方法,使用參數InterceptorRegistry物件加入自己的攔截器,可以新增指定攔截路徑或去掉某些過濾路徑,還可以設定攔截器的優先權order,優先權由小到大,預設0;
多個攔截器的執行順序:
preHandle方法依照order由小到大順序,執行完controller後,其他方法則反向順序,跟過濾器Filter類似;
測試啟動類,預設配置:
/** * 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類:
/** * 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.RestController; /** * @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=" + Thread.currentThread().getId()); Thread.sleep(2000); return "abcdefg"; } }; System.out.println(">>>b()"); return callable; } }
兩個自訂攔截器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.ModelAndView; /** * @author XWF * */ public class MyInterceptor1 implements HandlerInterceptor { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) 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()); } }
設定攔截器:
/** * 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 } }
發送一個post測試請求:http://192.168.1.30:8080/interceptor/a?s=hello,攔截器2的order預設0,攔截器1的order為1,preHandle先執行2的,controller執行之後,剩下的Handle都是先執行1再執行2的;
#發送preHandle回傳false的請求:http://192.168 .1.30:8080/interceptor/a?s=hello123456789,攔截器1的preHandle返回false後,直接執行2的afterCompletion;
發送測試callable的請求:http ://192.168.1.30:8080/interceptor/b?s=hello,攔截路徑配置跳過攔截器1只執行攔截器2,透過threadid可以看到前後使用的是兩個執行緒;
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