如何在该请求中添加Content-Type application/json

  - Python（使用requests库）：

    ```python

    import requests

    headers = {

        "Content-Type": "application/json"

    }

    response = requests.post(url, headers=headers, json=data)

    ```

  - JavaScript（使用fetch API）：

    ```javascript

    fetch(url, {

        method: 'POST',

        headers: {

            'Content-Type': 'application/json'

        },

        body: JSON.stringify(data)

    })

    .then(response => response.json())

    .then(data => console.log(data))

    .catch(error => console.error(error));

    ```

  - Java（使用Apache HttpClient库）：

    ```java

    import org.apache.http.HttpEntity;

    import org.apache.http.HttpHeaders;

    import org.apache.http.client.methods.HttpPost;

    import org.apache.http.entity.ContentType;

    import org.apache.http.entity.StringEntity;

    import org.apache.http.impl.client.CloseableHttpClient;

    import org.apache.http.impl.client.HttpClients;

    import org.apache.http.util.EntityUtils;

    CloseableHttpClient httpClient = HttpClients.createDefault();

    HttpPost httpPost = new HttpPost(url);

    httpPost.setHeader(HttpHeaders.CONTENT_TYPE, "application/json");

    StringEntity requestEntity = new StringEntity(jsonData, ContentType.APPLICATION_JSON);

    httpPost.setEntity(requestEntity);

    CloseableHttpResponse response = httpClient.execute(httpPost);

    HttpEntity responseEntity = response.getEntity();

    String responseBody = EntityUtils.toString(responseEntity);

    ```