springboot config 拦截器使用方法实例详解

package com.example.springboot.config.intercepter;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * @desc 自定义拦截器，使用 @Component 让 Spring 管理其生命周期
 * @Author wangsh
 * @date 2018/5/6 17:06
 * @return
 */
@Component
public class TestIntercepter implements HandlerInterceptor {
  @Override
  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
   System.out.println(">>>preHandle>>>>>>>在请求处理之前进行调用（Controller方法调用之前）");
   setCrossDomain(response);
   return true;// 只有返回true才会继续向下执行，返回false取消当前请求
  }
  @Override
  public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
   // 请求处理之后进行调用，但是在视图被渲染之前（Controller方法调用之后）;
   System.out.println(">>>postHandle>>>>>>>请求处理之后进行调用，但是在视图被渲染之前（Controller方法调用之后）");
  }
  @Override
  public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
   // 在整个请求结束之后被调用，也就是在DispatcherServlet 渲染了对应的视图之后执行（主要是用于进行资源清理工作）;
   System.out.println(">>>postHandle>>>>>>>在整个请求结束之后被调用，也就是在DispatcherServlet 渲染了对应的视图之后执行（主要是用于进行资源清理工作）");
  }
  /**
  * @param @param response  设定文件
  * @return void  返回类型
  * @throws
  * @Title: setCrossDomain
  * @Description: TODO(设置跨域问题)
  */
  private void setCrossDomain(HttpServletResponse response) {
   response.addHeader("Access-Control-Allow-Origin", "*");
   response.addHeader("Access-Control-Allow-Methods", "POST,GET");
   response.addHeader("Access-Control-Allow-Credentials", "true");
  }
}

package com.example.springboot.config.config;
import com.example.springboot.config.intercepter.TestIntercepter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
/**
 * 注册bean
 */
@Configuration
public class InterceptorConfig extends WebMvcConfigurerAdapter {
  @Autowired
  private TestIntercepter testInterceptor;
  @Override
  public void addInterceptors(InterceptorRegistry registry) {
   registry.addInterceptor(testInterceptor);
  }
}

package com.example.springboot.config.conroller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/user")
public class UserController {
  @RequestMapping("/hello")
  public String hello(){
    return "hello";
  }
}

package com.example.springboot.config;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class SpringbootConfigApplication {
  public static void main(String[] args) {
   SpringApplication.run(SpringbootConfigApplication.class, args);
  }
}