签发数字凭据

借助 Credential Manager API，您可以向 Android 持有者（也称为“钱包”）应用签发凭据。本指南介绍了如何将凭据保存到用户的首选持有者。

实现

本部分详细介绍了签发数字凭据所需的步骤。

添加依赖项

将以下依赖项添加到 Gradle 构建脚本中：

Kotlin

dependencies {
    implementation("androidx.credentials:credentials:1.7.0-alpha02")
    implementation("androidx.credentials:credentials-play-services-auth:1.7.0-alpha02")
}

Groovy

dependencies {
    implementation "androidx.credentials:credentials:1.7.0-alpha02"
    implementation "androidx.credentials:credentials-play-services-auth:1.7.0-alpha02"
}

初始化 Credential Manager

初始化 CredentialManager 类的实例。

val credentialManager = CredentialManager.create(context)

创建发放请求

数字凭据创建请求应包含遵循 OpenID4VCI 标准协议的 JSON 字符串。以下是 OpenID4VCI 请求的示例：

"requests": [
  {
    "protocol": "openid4vci-v1",
    "data": {
      "credential_issuer": "https://digital-credentials.dev",
      "credential_configuration_ids": [
        "com.emvco.payment_card"
      ],
      "grants": {
        "urn:ietf:params:oauth:grant-type:pre-authorized_code": {
          "pre-authorized_code": "..."
        }
      }
    }
  }
]

创建包含签发请求的 CreateDigitalCredentialRequest。

val issuanceRequestJson = "{ ... }" // Your issuance JSON
val createRequest = CreateDigitalCredentialRequest(
    requestJson = issuanceRequestJson,
    origin = null
)

发出签发请求

使用 createCredential 函数向用户持有者发放凭据。此函数会启动 Credential Manager 底部动作条选择器，让用户选择他们希望将凭据存储在哪个持有者应用中。

try {
    val response = credentialManager.createCredential(
        context = context,
        request = createRequest
    )
    handleSuccess(response as CreateDigitalCredentialResponse)
} catch (e: CreateCredentialException) {
    handleCreateException(e)
}

处理响应

在您发出签发请求后，系统会返回 CreateDigitalCredentialResponse。此响应包含一个 responseJson 字符串，用于描述签发结果。

fun handleSuccess(response: CreateDigitalCredentialResponse) {
    val responseJson = response.responseJson
    // Parse responseJson according to your protocol (e.g. OpenID4VCI)
}

处理异常

如果签发流程失败，createCredential 会抛出 CreateCredentialException，您的应用应处理此异常：

fun handleCreateException(e: CreateCredentialException) {
    when (e) {
        is CreateCredentialCancellationException -> {
            // The user canceled the flow
        }
        is CreateCredentialInterruptedException -> {
            // The flow was interrupted (e.g. by another UI element)
        }
        is CreateCredentialNoCreateOptionException -> {
            // No wallet application is available to handle the request
        }
        is CreateCredentialUnsupportedException -> {
            // The device or the system doesn't support this request
        }
        is CreateCredentialProviderConfigurationException -> {
            // There is a configuration issue with the wallet provider
        }
        is CreateCredentialCustomException -> {
            // A protocol-specific error occurred
            val errorType = e.type
            val errorMessage = e.message
        }
        is CreateCredentialUnknownException -> {
            // An unknown error occurred
        }
        else -> {
            // Generic error handling
        }
    }
}