003-Spring-Guide

一：步骤

1-：在https://start.spring.io/新建项目，其中，Dependencies选择“Spring Web”；

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二：相关命令

./mvnw spring-boot:run     启动项目

三：简单的Spring例子：

package com.time.message;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class MessageApplication {

    public static void main(String[] args) {
        SpringApplication.run(MessageApplication.class, args);
    }

    @GetMapping("/hello")
    public String hello(@RequestParam(value = "name",defaultValue = "World") String name){
        return  String.format("Hello %s!",name);
    }
}

四：RESTful Web Service

package com.time.message.restservice;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.concurrent.atomic.AtomicLong;

@RestController
public class GreetingController {
    private static final String template = "Hello %s!";
    private final AtomicLong counter = new AtomicLong();

    @GetMapping("/greeting")
    public Greeting greeting(@RequestParam(value = "name",defaultValue = "World") String name){
        return  new Greeting(counter.incrementAndGet(),String.format(template,name));
    }
}

其中需要关注：

  @GetMapping("/greeting")                GET请求方式
  @PostMapping("/greeting")             POST请求方式
  @RequestMapping("/greeting")        GET/POST
  @RequestMapping(method=GET)    设置为GET

 即为： @RequestMapping(value = "/greeting",method = RequestMethod.GET)

五：Scheduling Tasks

package com.time.message.restservice;

import org.springframework.stereotype.Component;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
public class ScheduledTasks {
    private static final Logger log = LoggerFactory.getLogger(ScheduledTasks.class);

    private static final SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");

    @Scheduled(fixedRate = 5000)
    public void reportCurrentTime() {
        log.info("The time is now {}", dateFormat.format(new Date()));
    }
}

同时，需要在Application中，添加注解-“EnableScheduling”：

package com.time.message;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;

@SpringBootApplication
@EnableScheduling
public class MessageApplication {
    public static void main(String[] args) {
        SpringApplication.run(MessageApplication.class, args);
    }
}