基于Spring Boot的天气预报服务

傷城~ 2022-06-09 12:42 181阅读 0赞

本文，我们将基于 Spring Boot 技术来实现一个微服务天气预报服务接口——micro-weather-basic。micro-weather-basic 的作用是实现简单的天气预报功能，可以根据不同的城市，查询该城市的实时天气情况。

## 开发环境 ##

*  Gradle 4.0
 *  Spring Boot 1.5.6
 *  Apache HttpClient 1.5.3

## 数据来源 ##

理论上，天气的数据是天气预报的实现基础。本应用与实际的天气数据无关，理论上，可以兼容多种数据来源。但为求简单，我们在网上找了一个免费、可用的天气数据接口。

*  天气数据来源为中华万年历。例如：  
    
    
     *  通过城市名字获得天气数据 ：[http://wthrcdn.etouch.cn/weather\_mini?city=深圳][http_wthrcdn.etouch.cn_weather_mini_city]
     *  通过城市id获得天气数据：[http://wthrcdn.etouch.cn/weather\_mini?citykey=101280601][http_wthrcdn.etouch.cn_weather_mini_citykey_101280601]
 *  城市ID列表。每个城市都有一个唯一的ID作为标识。见 [http://cj.weather.com.cn/support/Detail.aspx?id=51837fba1b35fe0f8411b6df][http_cj.weather.com.cn_support_Detail.aspx_id_51837fba1b35fe0f8411b6df] 或者 [http://mobile.weather.com.cn/js/citylist.xml][http_mobile.weather.com.cn_js_citylist.xml]。

调用天气服务接口示例，我们以“深圳”城市为例，可用看到如下天气数据返回。

{
        "data": { "yesterday": { "date": "1日星期五", "high": "高温 33℃", "fx": "无持续风向", "low": "低温 26℃", "fl": "<![CDATA[<3级]]>", "type": "多云" }, "city": "深圳", "aqi": "72", "forecast": [ { "date": "2日星期六", "high": "高温 32℃", "fengli": "<![CDATA[<3级]]>", "low": "低温 26℃", "fengxiang": "无持续风向", "type": "阵雨" }, { "date": "3日星期天", "high": "高温 29℃", "fengli": "<![CDATA[5-6级]]>", "low": "低温 26℃", "fengxiang": "无持续风向", "type": "大雨" }, { "date": "4日星期一", "high": "高温 29℃", "fengli": "<![CDATA[3-4级]]>", "low": "低温 26℃", "fengxiang": "西南风", "type": "暴雨" }, { "date": "5日星期二", "high": "高温 31℃", "fengli": "<![CDATA[<3级]]>", "low": "低温 27℃", "fengxiang": "无持续风向", "type": "阵雨" }, { "date": "6日星期三", "high": "高温 32℃", "fengli": "<![CDATA[<3级]]>", "low": "低温 27℃", "fengxiang": "无持续风向", "type": "阵雨" } ], "ganmao": "风较大，阴冷潮湿，较易发生感冒，体质较弱的朋友请注意适当防护。", "wendu": "29" },
        "status": 1000,
        "desc": "OK" }

我们通过观察数据，来了解每个返回字段的含义。

*  “city”: 城市名称
 *  “aqi”: 空气指数,
 *  “wendu”: 实时温度
 *  “date”: 日期，包含未来5天
 *  “high”:最高温度
 *  “low”: 最低温度
 *  “fengli”: 风力
 *  “fengxiang”: 风向
 *  “type”: 天气类型

以上数据，是我们需要的天气数据的核心数据，但是，同时也要关注下面两个字段：

*  “status”: 接口调用的返回状态，返回值“1000”,意味着数据是接口正常
 *  “desc”: 接口状态的描述，“OK”代表接口正常

重点关注返回值不是“1000”的情况,说明，这个接口调用异常了。

## 初始化一个 Spring Boot 项目 ##

初始化一个 Spring Boot 项目 `micro-weather-basic`，该项目可以直接在我们之前章节课程中的 basic-gradle 项目基础进行修改。同时，为了优化项目的构建速度，我们对Maven中央仓库地址和 Gradle Wrapper 地址做了调整。其中细节暂且不表，读者可以自行参阅源码，或者学习笔者所著的《Spring Boot 教程》（[https://github.com/waylau/spring-boot-tutorial][https_github.com_waylau_spring-boot-tutorial]）。其原理，我也整理到我的博客中了：

*  [https://waylau.com/change-gradle-wrapper-distribution-url-to-local-file/][https_waylau.com_change-gradle-wrapper-distribution-url-to-local-file]
 *  [https://waylau.com/use-maven-mirrors/][https_waylau.com_use-maven-mirrors]

## 项目配置 ##

添加 Apache HttpClient 的依赖，来作为我们Web请求的客户端。

// 依赖关系
    dependencies {
        //...
    
        // 添加  Apache HttpClient 依赖
        compile('org.apache.httpcomponents:httpclient:4.5.3')
    
        //...
    }

## 创建天气信息相关的值对象 ##

创建`com.waylau.spring.cloud.vo`包，用于相关值对象。创建天气信息类 Weather

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 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 String getGanmao() {
            return ganmao;
        }
        public void setGanmao(String ganmao) {
            this.ganmao = ganmao;
        }
        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;
        }
    }

昨日天气信息：

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 Yesterday() {
    
        }
    
        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;
        }
    
    }

未来天气信息：

public class Forecast implements Serializable { 
    
        private static final long serialVersionUID = 1L;
    
        private String date;
        private String high;
        private String fengxiang;
        private String low;
        private String fengli;
        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 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;
        }
    
        public Forecast() {
    
        }
    
    }

WeatherResponse 作为整个消息的返回对象

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;
        }
    
    }

## 服务接口及实现 ##

定义了获取服务的两个接口方法

public interface WeatherDataService { 
    
        /** * 根据城市ID查询天气数据 * @param cityId * @return */
        WeatherResponse getDataByCityId(String cityId);
    
        /** * 根据城市名称查询天气数据 * @param cityId * @return */
        WeatherResponse getDataByCityName(String cityName);
    }

其实现为:

@Service
    public class WeatherDataServiceImpl implements WeatherDataService { 
    
        @Autowired
        private RestTemplate restTemplate;
    
        private final String WEATHER_API = "http://wthrcdn.etouch.cn/weather_mini";
    
        @Override
        public WeatherResponse getDataByCityId(String cityId) {
            String uri = WEATHER_API + "?citykey=" + cityId;
            return this.doGetWeatherData(uri);
        }
    
        @Override
        public WeatherResponse getDataByCityName(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();
            }
    
            ObjectMapper mapper = new ObjectMapper();
            WeatherResponse weather = null;
    
            try {
                weather = mapper.readValue(strBody, WeatherResponse.class);
            } catch (IOException e) {
                e.printStackTrace();
            }
    
            return weather;
        }
    
    }

返回的天气信息采用了 Jackson 来进行反序列化成为 WeatherResponse 对象。

## 控制器层 ##

控制器层暴露了RESTful API 地址。

@RestController
    @RequestMapping("/weather") 
    public class WeatherController { 
    
        @Autowired
        private WeatherDataService weatherDataService;
    
        @GetMapping("/cityId/{cityId}")
        public WeatherResponse getReportByCityId(@PathVariable("cityId") String cityId) {
            return weatherDataService.getDataByCityId(cityId);
        }
    
        @GetMapping("/cityName/{cityName}")
        public WeatherResponse getReportByCityName(@PathVariable("cityName") String cityName) {
            return weatherDataService.getDataByCityName(cityName);
        }
    
    }

`@RestController`自动会将返回的数据，序列化成 JSON数据格式。

## 配置类 ##

RestConfiguration 是 RestTemplate 的配置类。

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

## 访问API ##

运行项目之后，访问项目的 API ：

*  [http://localhost:8080/weather/cityId/101280601][http_localhost_8080_weather_cityId_101280601]
 *  [http://localhost:8080/weather/cityName/惠州][http_localhost_8080_weather_cityName]

能看到如下的数据返回

![weather-data][]

## 源码 ##

本章节的源码，见 [https://github.com/waylau/spring-cloud-tutorial/][https_github.com_waylau_spring-cloud-tutorial] `samples`目录下的`micro-weather-basic`。

## 参考引用 ##

*  [https://waylau.com/spring-boot-weather-report/][https_waylau.com_spring-boot-weather-report]
 *  [https://github.com/waylau/spring-boot-tutorial][https_github.com_waylau_spring-boot-tutorial]

[http_wthrcdn.etouch.cn_weather_mini_city]: http://wthrcdn.etouch.cn/weather_mini?city=深圳
[http_wthrcdn.etouch.cn_weather_mini_citykey_101280601]: http://wthrcdn.etouch.cn/weather_mini?citykey=101280601
[http_cj.weather.com.cn_support_Detail.aspx_id_51837fba1b35fe0f8411b6df]: http://cj.weather.com.cn/support/Detail.aspx?id=51837fba1b35fe0f8411b6df
[http_mobile.weather.com.cn_js_citylist.xml]: http://mobile.weather.com.cn/js/citylist.xml
[https_github.com_waylau_spring-boot-tutorial]: https://github.com/waylau/spring-boot-tutorial
[https_waylau.com_change-gradle-wrapper-distribution-url-to-local-file]: https://waylau.com/change-gradle-wrapper-distribution-url-to-local-file/
[https_waylau.com_use-maven-mirrors]: https://waylau.com/use-maven-mirrors/
[http_localhost_8080_weather_cityId_101280601]: http://localhost:8080/weather/cityId/101280601
[http_localhost_8080_weather_cityName]: http://localhost:8080/weather/cityName/惠州
[weather-data]: https://raw.githubusercontent.com/waylau/spring-cloud-tutorial/master/images/msa-boot/weather-data.jpg
[https_github.com_waylau_spring-cloud-tutorial]: https://github.com/waylau/spring-cloud-tutorial/
[https_waylau.com_spring-boot-weather-report]: https://waylau.com/spring-boot-weather-report/