java - 从 firebase 数据库中删除一个值

Question

我尝试从 Firebase 数据库中删除节点，但没有任何反应。

这是我的代码:

FileInputStream serviceAccount = new FileInputStream(keyPath);

FirebaseOptions options = new FirebaseOptions.Builder()
    .setCredentials(GoogleCredentials.fromStream(serviceAccount))
    .setDatabaseUrl(databaseUrl)
    .build();

FirebaseApp.initializeApp(options);

DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
ref.child("Users").child(uid).child("name").removeValue()

这是输出:

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J:See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

09-02-2018 05:43:53 PM - [START] - Start action : Statement - serviceAccount = new java.io.FileInputStream(keyPath) 09-02-2018 05:43:53 PM - [END] - End action : Statement - serviceAccount = new java.io.FileInputStream(keyPath) 09-02-2018 05:43:53 PM - [START] - Start action : Statement - options = new com.google.firebase.FirebaseOptions$Builder().setCredentials(com.google.auth.oauth2.GoogleCredentials.fromStream(serviceAccount)).setDatabaseUrl(databaseUrl).build() 09-02-2018 05:43:53 PM - [END] - End action : Statement - options = new com.google.firebase.FirebaseOptions$Builder().setCredentials(com.google.auth.oauth2.GoogleCredentials.fromStream(serviceAccount)).setDatabaseUrl(databaseUrl).build() 09-02-2018 05:43:53 PM - [START] - Start action : Statement - com.google.firebase.FirebaseApp.initializeApp(options) 09-02-2018
05:43:53 PM - [END] - End action : Statement - com.google.firebase.FirebaseApp.initializeApp(options) 09-02-2018
05:43:53 PM - [START] - Start action : Statement - ref = com.google.firebase.database.FirebaseDatabase.getInstance().getReference()
09-02-2018 05:43:53 PM - [END] - End action : Statement - ref = com.google.firebase.database.FirebaseDatabase.getInstance().getReference()
09-02-2018 05:43:53 PM - [START] - Start action : Statement ref.child("Users").child(uid).child("name").removeValue() 09-02-2018
05:43:53 PM - [END] - End action : Statement - ref.child("Users").child(uid).child("name").removeValue() 09-02-2018
05:43:53 PM - [PASSED] - Test Cases/V2/General/Draft 09-02-2018
05:43:53 PM - [END] - End Test Case : Test Cases/V2/General/Draft

正如我所说，数据库没有任何变化。
有什么想法吗？

Answer 1

我最终在 github 上找到了这个存储库:https://github.com/bane73/firebase4j
在自述文件中，有一个简单的示例，通过仅提供数据库 url 和要写入的数据来将值写入 firebase 数据库。
要删除某个值，只需将该值设置为 null:

String url = 'https://project-name.firebaseio.com/users/user1/email'

//Initialize database
Firebase firebase = new Firebase(baseUrl);

//remove email of user1
Map<String, Object> dataMap = new LinkedHashMap<String, Object>();
dataMap.put("some str", null);
firebase.put(dataMap)