java发送短信验证码

要发送短信验证码，你需要使用短信服务提供商的 API。以下是一个使用阿里云短信服务的示例代码：

import java.util.Random;
import com.aliyuncs.DefaultAcsClient;
import com.aliyuncs.IAcsClient;
import com.aliyuncs.exceptions.ClientException;
import com.aliyuncs.profile.DefaultProfile;
import com.aliyuncs.profile.IClientProfile;
import com.aliyuncs.sms.model.v20170605.SendSmsRequest;
import com.aliyuncs.sms.model.v20170605.SendSmsResponse;

public class SmsSender {
    private static final String ACCESS_KEY_ID = "your_access_key_id";
    private static final String ACCESS_KEY_SECRET = "your_access_key_secret";
    private static final String SIGN_NAME = "your_sign_name";
    private static final String TEMPLATE_CODE = "your_template_code";

    public static void sendSms(String phone) throws ClientException {
        IClientProfile profile = DefaultProfile.getProfile("cn-hangzhou", ACCESS_KEY_ID, ACCESS_KEY_SECRET);
        DefaultProfile.addEndpoint("cn-hangzhou", "cn-hangzhou", "Sms", "sms.aliyuncs.com");

        IAcsClient client = new DefaultAcsClient(profile);

        SendSmsRequest request = new SendSmsRequest();
        request.setPhoneNumbers(phone);
        request.setSignName(SIGN_NAME);
        request.setTemplateCode(TEMPLATE_CODE);

        String code = String.format("%04d", new Random().nextInt(10000));
        request.setTemplateParam("{\"code\":\"" + code + "\"}");

        SendSmsResponse response = client.getAcsResponse(request);
        System.out.println("短信发送结果：" + response.getCode());
    }
}

在上面的代码中，你需要替换以下常量：

- `your_access_key_id`：你的阿里云 Access Key ID
- `your_access_key_secret`：你的阿里云 Access Key Secret
- `your_sign_name`：你在阿里云短信服务中设置的签名名称
- `your_template_code`：你在阿里云短信服务中设置的短信模板编号

使用时，你只需要调用 `sendSms` 方法并传入要发送的手机号码即可。该方法会生成一个 4 位的随机验证码并发送到指定的手机号码上。