android studio firebase数据库:如何从子节点获取数据

import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.ValueEventListener;

FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference myRef = database.getReference("子节点路径");

myRef.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        // 从子节点获取数据
        String data = dataSnapshot.getValue(String.class);
        // 处理数据
        // ...
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {
        // 处理取消事件
        // ...
    }
});