将firebase数据库url(String)分配给Database Reference变量? [英] Assign a firebase database url(String) to a Database Reference variable?

问题描述

我试图将包含数据库中某个位置的url的字符串分配给DatabaseReference类型. 示例:

I'm trying to assign a string that contains a url for a place in my database to a DatabaseReference type. Example:

String strRef = "my database url";
DatabaseReference ref = //here I want to assign the content of strRef.

更新(从评论到Alex的回答):

Update (from comment to Alex's answer):

我从另一个活动中获得了指向数据库中某个位置的特定URL.现在，我需要将其转换为DatabaseReference类型，以便能够从数据库中的该位置读取该URL.

I'm getting from another activity a specific url that point on a place in my database.and now I need to cast it to a DatabaseReference type that I'll be able to read from this place in my database.

推荐答案

如果从某处获得指向数据库中某个位置的完整URL，则可以使用以下方法为该位置创建DatabaseReference:

If you get a full URL to a location in the database from somewhere, you can create a DatabaseReference to that location with:

String url = "https://<your-project>.firebaseio.com/path/to/data";
DatabaseReference ref = FirebaseDatabase.getInstance().getReferenceFromUrl(url);

因此，如果您的URL以https://<your-project>.firebaseio.com/开头，则上述方法适用.

So the above works if your URL starts with https://<your-project>.firebaseio.com/.

如果获得完整路径，则可以使用:

If you get a full path instead, you'd use:

String path = "/path/to/data";
DatabaseReference ref = FirebaseDatabase.getInstance().getReference(path);

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