java-base-maven/springboot-main/src/main/java/com/alvin/controller/UserController.java

package com.alvin.controller;

import com.alvin.util.DateUtil;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.concurrent.ConcurrentHashMap;

@RestController
@RequestMapping("user")
public class UserController {
    @GetMapping("age")
    public String test1(Integer age) {
        return age + "!";
    }

    public volatile ConcurrentHashMap<String, String> flags=new ConcurrentHashMap<>();

    @GetMapping("startPrint")
    public String startPrint(String flag) {
        flags.put(flag, flag);
        new Thread(() -> {
            while (flags.contains(flag)) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
                System.out.println(flag + DateUtil.getEpochMilli());
            }
        }).start();
        return "1";
    }

    @GetMapping("cancelPrint")
    public String cancelPrint(String flag) {
        flags.remove(flag);
        return "ok";
    }

}