利用springboot快速实现一个查询数据系统（一）

上班的时候，公司负责人给我说让我看下springboot和springcloud，后面项目也许会用到，我就查看相关资料，然后结合资料自己动手写了下代码，从中出现一些问题已经解决一些问题。

参考书籍：柳伟卫编著的书籍《SpringCloud微服务架构开发实战》

首先我们需要找到天气预报的数据源：通过网上查找，有免费的，可用的天气数据接口：

有两种方式：

通过城市名称获取天气数据信息： "http://wthrcdn.etouch.cn/weather_mini？city=城市名称

通过城市ID获取天气数据信息： "http://wthrcdn.etouch.cn/weather_mini？citykey=城市编号ID

一。首先放出我的项目的结构：

二。创建springboot项目，并添加依赖：

<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpclient</artifactId>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-test -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>

三。创建用到的相关对象vo

    天气信息类对象：Weather

   package com.yian.springboot.vo;

import java.io.Serializable;
import java.util.List;
/**
 * 
 * @Description: 天气信息类对象
 * @ClassName: Weather
 * @author chengshengqing-YiAn  2019年2月28日 上午10:02:48
 * @see TODO
 */
public class Weather implements Serializable {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	private String city;
	private String aqi;//
	private String wendu;
	private String ganmao;
	private Yesterday  yesterday;
	private List<Forecast> forecast;
	
	public String getGanmao() {
		return ganmao;
	}
	public void setGanmao(String ganmao) {
		this.ganmao = ganmao;
	}
	public String getCity() {
		return city;
	}
	public void setCity(String city) {
		this.city = city;
	}
	public String getAqi() {
		return aqi;
	}
	public void setAqi(String aqi) {
		this.aqi = aqi;
	}
	public String getWendu() {
		return wendu;
	}
	public void setWendu(String wendu) {
		this.wendu = wendu;
	}
	public Yesterday getYesterday() {
		return yesterday;
	}
	public void setYesterday(Yesterday yesterday) {
		this.yesterday = yesterday;
	}
	public List<Forecast> getForecast() {
		return forecast;
	}
	public void setForecast(List<Forecast> forecast) {
		this.forecast = forecast;
	}
	@Override
	public String toString() {
		return "Weather [city=" + city + ", aqi=" + aqi + ", wendu=" + wendu + ", yesterday="
				+ yesterday + ", forecast=" + forecast + "]";
	}
}

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2。昨日天气信息类：Yesterday

package com.yian.springboot.vo;

import java.io.Serializable;
/**
 * 
 * @Description: 昨日天气信息类 
 * @ClassName: Yesterday
 * @author chengshengqing-YiAn  2019年2月28日 上午10:04:29
 * @see TODO
 */
public class Yesterday implements Serializable{

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	private String date;
	private String high;
	private String fx;
	private String low;
	private String fl;
	private String type;
	public String getDate() {
		return date;
	}
	public void setDate(String date) {
		this.date = date;
	}
	public String getHigh() {
		return high;
	}
	public void setHigh(String high) {
		this.high = high;
	}
	public String getFx() {
		return fx;
	}
	public void setFx(String fx) {
		this.fx = fx;
	}
	public String getLow() {
		return low;
	}
	public void setLow(String low) {
		this.low = low;
	}
	public String getFl() {
		return fl;
	}
	public void setFl(String fl) {
		this.fl = fl;
	}
	public String getType() {
		return type;
	}
	public void setType(String type) {
		this.type = type;
	}
	@Override
	public String toString() {
		return "Yesterday [date=" + date + ", high=" + high + ", fx=" + fx + ", low=" + low + ", fl=" + fl + ", type="
				+ type + "]";
	}

}

3。未来天气信息类：Forecast

package com.yian.springboot.vo;

import java.io.Serializable;

/**
 * 
 * @Description: 未来天气信息类：Forecast 
 * @ClassName: Forecast
 * @author chengshengqing-YiAn  2019年2月28日 上午10:05:25
 * @see TODO
 */
public class Forecast  implements Serializable{

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	private String date;//琪日期
	private String high;//最高温度
	private String fengxiang;//风向
	private String low;//最低温度
	private String fengli;//风力
	private String type;//天气类型
	public String getDate() {
		return date;
	}
	public void setDate(String date) {
		this.date = date;
	}
	public String getHigh() {
		return high;
	}
	public void setHigh(String high) {
		this.high = high;
	}
	public String getFengxiang() {
		return fengxiang;
	}
	public void setFengxiang(String fengxiang) {
		this.fengxiang = fengxiang;
	}
	public String getLow() {
		return low;
	}
	public void setLow(String low) {
		this.low = low;
	}
	public String getFengli() {
		return fengli;
	}
	public void setFengli(String fengli) {
		this.fengli = fengli;
	}
	public String getType() {
		return type;
	}
	public void setType(String type) {
		this.type = type;
	}
	@Override
	public String toString() {
		return "Forecast [date=" + date + ", high=" + high + ", fengxiang=" + fengxiang + ", low=" + low + ", fengli="
				+ fengli + ", type=" + type + "]";
	}
}

4. 消息返回对象：WeatherResponse

package com.yian.springboot.vo;

import java.io.Serializable;
/**
 * 
 * @Description:  消息返回对象：WeatherResponse 
 * @ClassName: WeatherResponse
 * @author chengshengqing-YiAn  2019年2月28日 上午10:06:35
 * @see TODO
 */
public class WeatherResponse  implements Serializable{

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	private Weather data; //消息数据
	private String  status; //消息状态
	private String desc;//消息描述
	public Weather getData() {
		return data;
	}
	public void setData(Weather data) {
		this.data = data;
	}
	public String getStatus() {
		return status;
	}
	public void setStatus(String status) {
		this.status = status;
	}
	public String getDesc() {
		return desc;
	}
	public void setDesc(String desc) {
		this.desc = desc;
	}
	@Override
	public String toString() {
		return "WeatherResponse [data=" + data + ", status=" + status + ", desc=" + desc + "]";
	}

}

四：创建根据城市名称和ID查询天气的接口

package com.yian.springboot.service;

import com.yian.springboot.vo.WeatherResponse;

/**
 * 
 * @Description: 根据城市和城市ID查询天气的接口 
 * @ClassName: WeatherDateService
 * @author chengshengqing-YiAn  2019年2月28日 上午10:20:02
 * @see TODO
 */
public interface WeatherDateService {

	//根据城市id查询天气
	WeatherResponse getDateByCityId(String cityId);
	//根据城市名字查询天气
	WeatherResponse getDateByCityName(String cityName);
}

五：创建实现类实现这个接口

package com.yian.springboot.service.Impl;

import java.io.IOException;
import java.util.concurrent.TimeUnit;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.yian.springboot.service.WeatherDateService;
import com.yian.springboot.vo.WeatherResponse;

@Service
public class WeatherDateServiceImpl implements WeatherDateService{
	
	
	
	@Autowired
	private RestTemplate restTemplate;
	private final String WEATHER_API="http://wthrcdn.etouch.cn/weather_mini";
    
	
	
	@Override
	public WeatherResponse getDateByCityId(String cityId) {
		
		String uri=WEATHER_API+"?citykey="+cityId;
		return this.doGetWeatherData(uri);
	}

	@Override
	public WeatherResponse getDateByCityName(String cityName) {
		String uri=WEATHER_API+"?city="+cityName;
		return this.doGetWeatherData(uri);
	}

	private WeatherResponse doGetWeatherData(String uri) {
		
		
		ResponseEntity<String> response=restTemplate.getForEntity(uri, String.class);
		 String strBody=null;
		 
		
		if(response.getStatusCodeValue()==200){
			strBody=response.getBody();
		}
		
		//jackson库中的类
		ObjectMapper mapper= new ObjectMapper();
		WeatherResponse weather=null;
		try {
			//mapper.readValue是将json结构转换成成java对象   
			//mapper.writeValue是将java对象转成json结构
			weather=mapper.readValue(strBody, WeatherResponse.class);
		} catch (IOException e) {
			e.printStackTrace();
		}
		return weather;
	}
	
}

 六：控制层代码

package com.yian.springboot.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.yian.springboot.service.WeatherDateService;
import com.yian.springboot.vo.WeatherResponse;
@SpringBootApplication
@RestController
@ComponentScan(basePackages={"com.yian.springboot.service","com.yian.springboot.config"})
@RequestMapping("/weather")
public class WeatherController {
	@Autowired
	private WeatherDateService weatherDateService;
	
	@RequestMapping("/cityId/{cityId}")
	public WeatherResponse getReportByCityId( @PathVariable("cityId") String cityId){
		return weatherDateService.getDateByCityId(cityId);
		
	}
	@RequestMapping("/cityName/{cityName}")
	public WeatherResponse getReportByCityName( @PathVariable("cityName") String cityName){
		return weatherDateService.getDateByCityName(cityName);
		
	}
	public static void main(String[] args) {
	      SpringApplication.run(WeatherController.class, args);
		}
	
}

 七：配置类

package com.yian.springboot.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
/**
 * 配置类
 * @Description: TODO 
 * @ClassName: RestConfiguration
 * @author chengshengqing-YiAn  2019年2月28日 上午10:25:38
 * @see TODO
 */
@Configuration
public class RestConfiguration {

	@Autowired
	private RestTemplateBuilder builder;
	@Bean
	public RestTemplate restTemplate(){
		return builder.build();
	}
	
	
}

八：启动项目，访问：http://localhost:8080/weather/cityId/101280603以后出现下面截图，证明访问成功。

   访问：http://localhost:8080/weather/cityName/福田区会出现以下截图，也说明访问成功。

注意：在这个项目启动的时候，报错了如下面截图所示：

据英文的提示是在配置中找不到一个指定自动注入类型的bean，经过多方排查得出结论：

　　正常情况下加上@Component注解的类会自动被Spring扫描到生成Bean注册到spring容器中，既然他说没找到，也就是该注解被没有被spring识别，问题的核心关键就在application类的注解SpringBootApplication上

解决办法：

1 .将接口与对应的实现类放在与application启动类的同一个目录或者他的子目录下，这样注解可以被扫描到，这是最省事的办法 

2 .在指定的application类上加上这么一行注解，手动指定application类要扫描哪些包下的注解

我当时的做法就是加了下面这个注解：问题解决了。

//@ComponentScan(basePackages={"com.yian.springboot.service","com.yian.springboot.config"})

劳动不易：转载请注明出处：https://blog.csdn.net/FindHuni/article/details/88016970

再次感谢：柳伟卫编著的书籍《SpringCloud微服务架构开发实战》