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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; afterCompletion: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;(controller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:

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/**
  * 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:

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/**
  * 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;
     }
    
}

两个自定义拦截器1和2:

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/**
  * 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" );
     }
    
}
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/**
  * 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:

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/**
  * 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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原文链接:https://blog.csdn.net/FlyLikeButterfly/article/details/129615703

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