java 获取 token 代码 事例

获取token是在进行接口调用时的重要步骤，下面是一个使用Java语言获取token的示例代码：

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class TokenExample {

    public static void main(String[] args) {
        String tokenUrl = "https://example.com/api/token";
        String clientId = "your_client_id";
        String clientSecret = "your_client_secret";
        
        try {
            URL url = new URL(tokenUrl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            conn.setDoOutput(true);

            String requestBody = "grant_type=client_credentials&client_id=" + clientId + "&client_secret=" + clientSecret;
            
            DataOutputStream wr = new DataOutputStream(conn.getOutputStream());
            wr.writeBytes(requestBody);
            wr.flush();
            wr.close();

            int responseCode = conn.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
                String inputLine;
                StringBuffer response = new StringBuffer();

                while ((inputLine = in.readLine()) != null) {
                    response.append(inputLine);
                }
                in.close();

                String token = response.toString();
                System.out.println("Token: " + token);
            } else {
                System.out.println("Failed to get token. Response code: " + responseCode);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

请注意，此代码仅是一个示例，实际情况下需要根据具体的接口和授权方式进行调整。在该例子中，我们使用了HTTP POST请求向指定的token获取接口发送了包含客户端ID和客户端秘钥的请求体，得到了返回的token数据，并将其打印输出。在实际使用中，可能还需要对获取到的token进行解析和存储以备后续接口调用使用。