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Java 从节点获取数据_Java_Android_Firebase_Firebase Realtime Database - Fatal编程技术网

Java 从节点获取数据

Java 从节点获取数据,java,android,firebase,firebase-realtime-database,Java,Android,Firebase,Firebase Realtime Database,如何检索这些值​​从user1 posts节点将它们添加到listview 我尝试了下面的代码,但我不知道下一步该怎么做 FirebaseDatabase.getInstance() .getReference("user1") .child("posts") .addValueEventListener( ); 要解决此问题,请使用以下代码: DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference()

如何检索这些值​​从user1 posts节点将它们添加到listview

我尝试了下面的代码,但我不知道下一步该怎么做

FirebaseDatabase.getInstance()
.getReference("user1")
.child("posts")
.addValueEventListener(

 );

要解决此问题,请使用以下代码:

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference postsRef = rootRef.child("users").child("user1").child("posts");
ValueEventListener eventListener = new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        List<String> list = new ArrayList<>();
        for(DataSnapshot ds : dataSnapshot.getChildren()) {
            String title = ds.child("title").getValue(String.class);
            String body = ds.child("body").getValue(String.class);
            list.add(title + " / " +  body);
            Log.d("TAG", title + " / " +  body);
        }
        ListView listView = (ListView) findViewById(R.id.list_view);
        ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, list);
        listView.setAdapter(arrayAdapter);
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {}
};
postsRef .addListenerForSingleValueEvent(eventListener);

你已经试过什么了吗?如果是这样,请编辑您的问题以包括以下内容。如果没有,请参阅和
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