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多用户应用程序 — Java SDK

Atlas Device SDK 已弃用。有关详细信息，请参阅弃用页面。

Realm 软件开发工具包（Realm SDK）允许多个用户在给定设备上同时登录应用。即使多个用户同时登录， Realm 客户端应用程序也会在单个活动用户的上下文中运行。您可以在经过身份验证的用户之间快速切换，而无需他们再次登录。

警告

任何登录用户都可以成为活动用户，而无需重新进行身份验证。 这可能是一个安全漏洞，具体取决于您的应用程序。例如，共享设备上的用户可以切换到同事的登录帐户，而无需提供他们的凭证或征求他们的明确许可。如果您的应用程序需要更严格的身份验证，请避免在用户之间切换，并且最好在对其他用户进行身份验证之前显式注销活动用户。

用户账户状态

当用户首次通过给定设备或浏览器上的 Realm SDK 登录时，SDK 会保存用户的信息并跟踪用户在设备上的状态。即使用户注销，其数据仍会保留在设备上，除非您主动删除用户。

以下状态描述了设备上的用户在任何给定时间的状态：

已通过身份验证：已登录设备且未注销或撤销会话的任何用户。
- Active ：当前正在给定设备上使用该应用的单个经过身份验证的用户。 SDK 会将此用户与传出请求相关联， Atlas App Services会评估数据访问权限并在此用户的上下文中运行函数。请参阅活跃用户以了解更多信息。
- 非活跃：所有经过身份验证但不是当前活跃用户的用户。您可以随时将活跃用户切换为当前非活跃用户。
已注销：在设备上进行身份验证但已注销或已撤销会话的任何用户。

下图展示了在特定事件发生时，Realm 客户端应用程序中的用户如何在各个状态之间进行转换：

该图表概述了用户可能处于的不同状态：已注销、已登录和处于活动状态、已登录和非活动状态。

向设备添加新用户

当用户首次登录设备时，Realm SDK 会自动将用户添加到该设备。用户登录后，将立即成为应用程序的活跃用户。

String appID = YOUR_APP_ID; // replace this with your App ID
App app = new App(new AppConfiguration.Builder(appID).build());
// Log in as Joe
Credentials joeCredentials = Credentials.emailPassword(firstUserEmail, firstUserPassword);
app.loginAsync(joeCredentials, it -> {
    if (it.isSuccess()) {
        // The active user is now Joe
        User joe = it.get();
        assert joe == app.currentUser();
    } else {
        Log.e("EXAMPLE", "Failed to log in: " + it.getError().getErrorMessage());
    }
});
// Log in as Emma
Credentials emmaCredentials = Credentials.emailPassword(secondUserEmail, secondUserPassword);
app.loginAsync(emmaCredentials, it -> {
    if (it.isSuccess()) {
        // The active user is now Emma
        User emma = it.get();
        assert emma == app.currentUser();
    } else {
        Log.e("EXAMPLE", "Failed to log in: " + it.getError().getErrorMessage());
    }
});

val appID: String = YOUR_APP_ID // replace this with your App ID
val app = App(AppConfiguration.Builder(appID).build())
// Log in as Joe
val joeCredentials = Credentials.emailPassword(firstUserEmail, firstUserPassword)
app.loginAsync(joeCredentials) {
    if (it.isSuccess) {
        // The active user is now Joe
        val joe = it.get()
        assert(joe === app.currentUser())
    } else {
        Log.e("EXAMPLE", "Failed to log in: ${it.error.errorMessage}")
    }
}
// Log in as Emma
val emmaCredentials = Credentials.emailPassword(secondUserEmail, secondUserPassword)
app.loginAsync(emmaCredentials) {
    if (it.isSuccess) {
        // The active user is now Emma
        val emma = it.get()
        assert(emma === app.currentUser())
    } else {
        Log.e("EXAMPLE", "Failed to log in: ${it.error.errorMessage}")
    }
}

列出设备上的所有用户

您可以访问权限设备上存储的所有用户帐户的列表。此列表包括在给定设备上登录过客户端应用的所有用户，无论他们当前是否经过身份验证。

Map<String, User> users = app.allUsers();
for (Map.Entry<String, User> user : users.entrySet()) {
    Log.v("EXAMPLE", "User: " + user.getKey());
}

val users = app.allUsers()
for ((key) in users) {
    Log.v("EXAMPLE", "User: $key")
}

从设备上删除用户

要从设备中删除有关用户的所有信息，请使用user.remove()或user.removeAsync()：

app.loginAsync(credentials, it -> {
    if (it.isSuccess()) {
        User user = it.get();
        user.removeAsync(result -> {
            if (result.isSuccess()) {
                Log.v("EXAMPLE", "Successfully removed user from device.");
            } else {
                Log.e("EXAMPLE", "Failed to remove user from device.");
            }
        });
    } else {
        Log.e("EXAMPLE", "Failed to log in: " + it.getError().getErrorMessage());
    }
});

app.loginAsync(credentials) {
    if (it.isSuccess) {
        val user = it.get()
        user.removeAsync { result: App.Result<User?> ->
            if (result.isSuccess) {
                Log.v("EXAMPLE",
                    "Successfully removed user from device.")
            } else {
                Log.e("EXAMPLE", "Failed to remove user from device.")
            }
        }
    } else {
        Log.e("EXAMPLE", "Failed to log in: ${it.error.errorMessage}")
    }
}

更改活动用户

您可以随时将应用程序的活跃用户快速切换成其他登录用户。

// Joe is already logged in and is the currently active user
User joe = app.currentUser();
// Log in as Emma
Credentials emmaCredentials = Credentials.emailPassword(secondUserEmail, secondUserPassword);
app.loginAsync(emmaCredentials, result -> {
    if (result.isSuccess()) {
        // The active user is now Emma
        User emma = result.get();
        assert emma == app.currentUser();
        // Switch active user back to Joe
        app.switchUser(joe);
        assert joe == app.currentUser();
    } else {
        Log.e("EXAMPLE", "Failed to log in: " + result.getError().getErrorMessage());
    }
});

// Joe is already logged in and is the currently active user
val joe = app.currentUser()
// Log in as Emma
val emmaCredentials = Credentials.emailPassword(
    secondUserEmail,
    secondUserPassword
)
app.loginAsync(emmaCredentials) { result ->
    if (result.isSuccess) {
        // The active user is now Emma
        val emma = result.get()
        assert(emma === app.currentUser())
        // Switch active user back to Joe
        app.switchUser(joe)
        assert(joe === app.currentUser())
    } else {
        Log.e("EXAMPLE", "Failed to log in: ${result.error.errorMessage}")
    }
}

后退

管理电子邮件/密码用户

来年

关联用户身份