OSS STS 获取Token 调用sdk 报错，要怎么解决

     // 创建一个 Aliyun Acs Client, 用于发起 OpenAPI 请求
            IClientProfile profile = DefaultProfile.getProfile(REGION_CN_SHENZHEN, assumeAccessKeyId,
                    assumeAccessKeySecret);
            DefaultAcsClient client = new DefaultAcsClient(profile);

            // 创建一个 AssumeRoleRequest 并设置请求参数
            final AssumeRoleRequest request = new AssumeRoleRequest();
            request.setMethod(MethodType.POST);
            request.setVersion(STS_API_VERSION);
            request.setProtocol(ProtocolType.HTTPS);

            request.setRoleArn(roleArn);
//            request.setRoleSessionName(roleSessionName);
//            request.setPolicy(policy);
            request.setDurationSeconds(new Long(15 * 60));

            // 发起请求，并得到response
            AssumeRoleResponse response = client.getAcsResponse(request);

AssumeRoleResponse response = client.getAcsResponse(request); //报错,错误如下