Java笔记：SpringBoot开发常用技术整合（3）

@EnableScheduling // 开启定时任务
package com.example.demo.task;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import java.text.SimpleDateFormat;
import java.util.Date;
@Component
public class HelloTask {
    private static final SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
    // 每3秒执行一次
    @Scheduled(fixedRate = 3000)
    public void echo(){
        System.out.println("echo: " + dateFormat.format(new Date()));
    }
}

@EnableAsync // 开启异步任务
package com.example.demo.task;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Component;
@Component
public class HelloTask {
    @Async
    public void sayHello() {
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

package com.example.demo.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class HelloInterceptor implements HandlerInterceptor {
    // 请求处理之前
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle");
        if("Tom".equals(request.getParameter("key"))){
            System.out.println("被拦截");
            return false;
        } else{
            System.out.println("放行");
            return true;
        }
    }
    // 请求处理之后
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle");
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion");
    }
}

package com.example.demo.config;
import com.example.demo.interceptor.HelloInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
//WebMvcConfigurerAdapter已经被废弃了
@Configuration
public class MyWebMvcConfigurer implements WebMvcConfigurer {
    // 拦截器按照顺序执行
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new HelloInterceptor()).addPathPatterns("/**");
    }
}