### 欢迎访问我的GitHub
> 这里分类和汇总了欣宸的全部原创(含配套源码)：[https://github.com/zq2599/blog_demos](https://github.com/zq2599/blog_demos)

### 本篇概览
- 本文的实战是开发一个springboot应用，通过RestTemplate获取公共的远程api服务，将查询到的指定城市的天气信息返回给前端；

### 创建springboot应用
- 基于maven创建一个springboot应用，pom信息如下，注意添加了**httpclient**：

```xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.2.RELEASE</version>
        <relativePath/> 
    </parent>
    <groupId>com.bolingcavalry</groupId>
    <artifactId>weatherservice</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>weatherservice</name>
    <description>Demo project for Spring Boot</description>

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

<dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.7</version>
        </dependency>

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

<build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>
```

- 启动类如下：

```java
package com.bolingcavalry.weatherservice;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

### 创建配置类
- 创建一个配置类，这里注意要使用HttpComponentsClientHttpRequestFactory作为RestTemplate构造方法的入参，这样才能支持gzip压缩的response，否则得到的就是乱码：

```java
package com.bolingcavalry.weatherservice;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.client.RestTemplate;
import java.nio.charset.StandardCharsets;

@Configuration
public class WeatherConfig {
    @Bean
    public RestTemplate restTemplate(){
        RestTemplate restTemplate = new RestTemplate(new HttpComponentsClientHttpRequestFactory());
        restTemplate.getMessageConverters().set(1, new StringHttpMessageConverter(StandardCharsets.UTF_8));
        return restTemplate;
    }
}
```

### 创建controller

- 创建一个controller来接收web请求，然后发起气象服务网站发起天气查询：

```java
package com.bolingcavalry.weatherservice.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.*;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
public class QueryWeather {

@Autowired
    RestTemplate restTemplate;

@RequestMapping(value = "/get/{city}", method = RequestMethod.GET)
    public String extern(@PathVariable("city") String city){
        String apiURL = "http://wthrcdn.etouch.cn/weather_mini?city=" + city;
        ResponseEntity<String> responseEntity = restTemplate.getForEntity(apiURL, String.class);

if(200==responseEntity.getStatusCodeValue()){
            return responseEntity.getBody();
        }else{
            return "error with code : " + responseEntity.getStatusCodeValue();
        }
    }
}
```

### 验证
- 启动应用WeatherserviceApplication，假如服务器IP地址是172.30.192.1，浏览器响应如下图，地址是：http://172.30.192.1:8080/get/深圳

![在这里插入图片描述](https://img-blog.csdnimg.cn/20190206233606329.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JvbGluZ19jYXZhbHJ5,size_16,color_FFFFFF,t_70)

### 源码下载
- 接下来的实战是编写Flink应用的源码，您可以选择直接从GitHub下载这个工程的源码，地址和链接信息如下表所示：

| 名称      |   链接 |   备注|
| :-------- | :----| :----|
| 项目主页| https://github.com/zq2599/blog_demos | 该项目在GitHub上的主页 |
| git仓库地址(https)| https://github.com/zq2599/blog_demos.git | 该项目源码的仓库地址，https协议 |
| git仓库地址(ssh)| git@github.com:zq2599/blog_demos.git | 该项目源码的仓库地址，ssh协议 |

- 这个git项目中有多个文件夹，本章源码在flinkkafkademo这个文件夹下，如下图红框所示：
![在这里插入图片描述](https://img-blog.csdnimg.cn/20190207144200102.jpg?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JvbGluZ19jYXZhbHJ5,size_16,color_FFFFFF,t_70)

### 欢迎关注ITpub：程序员欣宸
> [学习路上，你不孤单，欣宸原创一路相伴...](http://blog.itpub.net/70017844/)

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