1、API调用的第一步：购买API接口

关于API的购买这里就不过多陈述，网上一搜一大把,我这次教程使用的API是天行数据的API

2、获取ID和Key （类似账号密码）

这里就把我的KEY送给大家免费调用：

这个是查询全国疫情信息的API—可使用次数：100000

key=d557d60eeebe9fa695424a6e3930a8fd

1

3.使用你需要的请求示例（API文档里会有）

3.使用API文档里的请求示例（）

public class DataTest {

public static String request(String httpUrl, String httpArg) {

BufferedReader reader = null;

String result = null;

StringBuffer sbf = new StringBuffer();

//httpUrl = httpUrl + "?" + httpArg;

try {

URL url = new URL(httpUrl);

HttpURLConnection connection = (HttpURLConnection) url

.openConnection();

connection.setRequestMethod("GET");

InputStream is = connection.getInputStream();

reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));

String strRead = null;

while ((strRead = reader.readLine()) != null) {

sbf.append(strRead);

sbf.append("\r ");

}

reader.close();

result = sbf.toString();

} catch (Exception e) {

e.printStackTrace();

}

return result;

}

public static void main(String[] args) {

/**

* @param urlAll

* :请求接口

* @param httpArg

* :参数

* @return 返回结果

*/

String httpUrl = "http://api.tianapi.com/txapi/ncovcity/index?key=d557d60eeebe9fa695424a6e3930a8fd";

String httpArg="";

System.out.println(request(httpUrl,httpArg));

}

}

测试效果：

4.请求参数

5、添加请求参数，查询2020年3月12日的全国疫情数据

修改后的代码

public static String request(String httpUrl, String httpArg) {

BufferedReader reader = null;

String result = null;

StringBuffer sbf = new StringBuffer();

httpUrl = httpUrl + "&" + httpArg;

try {

URL url = new URL(httpUrl);

HttpURLConnection connection = (HttpURLConnection) url

.openConnection();

connection.setRequestMethod("GET");

InputStream is = connection.getInputStream();

reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));

String strRead = null;

while ((strRead = reader.readLine()) != null) {

sbf.append(strRead);

sbf.append("\r ");

}

reader.close();

result = sbf.toString();

} catch (Exception e) {

e.printStackTrace();

}

return result;

}

public static void main(String[] args) {

/**

* @param urlAll

* :请求接口

* @param httpArg

* :参数

* @return 返回结果

*/

String httpUrl = "http://api.tianapi.com/txapi/ncovcity/index?key=d557d60eeebe9fa695424a6e3930a8fd";

String httpArg="date=2020-03-12";

System.out.println(request(httpUrl,httpArg));

}

}

测试结果