安卓OAuth2 AppAuth库的kotlin示例

// 导入所需的库
import net.openid.appauth.AuthorizationService
import net.openid.appauth.AuthorizationRequest
import net.openid.appauth.AuthorizationResponse
import net.openid.appauth.AuthorizationException
import net.openid.appauth.TokenRequest
import net.openid.appauth.TokenResponse
import net.openid.appauth.AuthState
import net.openid.appauth.AuthState.AuthStateAction

// 创建授权请求
val authService = AuthorizationService(context)
val authRequest = AuthorizationRequest.Builder(
    configuration, // OAuth2配置
    clientId, // 客户端ID
    ResponseTypeValues.CODE, // 响应类型
    redirectUri // 重定向URI
)
    .setScope("openid profile email") // 请求的范围
    .build()

// 发起授权请求
val authIntent = authService.getAuthorizationRequestIntent(authRequest)
startActivityForResult(authIntent, AUTH_REQUEST_CODE)

// 处理授权回调
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    if (requestCode == AUTH_REQUEST_CODE) {
        val resp = AuthorizationResponse.fromIntent(data)
        val ex = AuthorizationException.fromIntent(data)
        
        if (resp != null) {
            // 授权成功，获取授权码
            val authCode = resp.authorizationCode
            
            // 创建令牌请求
            val tokenRequest = TokenRequest.Builder(
                configuration, // OAuth2配置
                clientId // 客户端ID
            )
                .setAuthorizationCode(authCode) // 授权码
                .setRedirectUri(redirectUri) // 重定向URI
                .build()
            
            // 发起令牌请求
            authService.performTokenRequest(tokenRequest) { tokenResponse, tokenException ->
                if (tokenResponse != null) {
                    // 令牌请求成功，获取访问令牌和刷新令牌
                    val accessToken = tokenResponse.accessToken
                    val refreshToken = tokenResponse.refreshToken
                    
                    // 更新授权状态
                    val authState = AuthState(authResponse, tokenResponse)
                    authState.update(tokenResponse, tokenException)
                    
                    // 保存授权状态
                    authState.performActionWithFreshTokens(authService) { accessToken, idToken, ex ->
                        // 使用访问令牌访问受保护资源
                        // 处理响应数据
                    }
                } else {
                    // 令牌请求失败，处理异常
                }
            }
        } else {
            // 授权失败，处理异常
        }
    }
}

// 在应用启动时恢复授权状态
val authState = AuthState.fromJson(savedAuthStateJson)
authState.performActionWithFreshTokens(authService) { accessToken, idToken, ex ->
    // 使用访问令牌访问受保护资源
    // 处理响应数据
}

// 在应用退出时保存授权状态
val savedAuthStateJson = authState.jsonSerializeString()