第一个firebase调用的主要代码:
refFB.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot snapshot, String previousChildName) {
FirebaseReq fbReq = snapshot.getValue(FirebaseReq.class);
service(fbReq);
}
...
});
对于维护和可读性,对我来说更清楚:
Run service(fbReq) in new thread.
public void service(FirebaseReq firebaseReq) {
value = dao(firebaseReq);
/*some other code which use value*/
}
public String dao(FirebaseReq firebaseReq) {
String result = null;
//the second firebase call
childRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot snapshot) {
result = snapshot.getName();
}
...
});
while (result== null){
}
return result;
}
或者更好地避免线程和等待循环,但具有不可读代码:
public void service(FirebaseReq firebaseReq) {
ValueEventListener valueEventListener = new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot snapshot) {
/*some other code which use value*/
}
...
});
dao(firebaseReq,valueEventListener);
}
public String dao(FirebaseReq firebaseReq,ValueEventListener valueEventListener) {
//the second firebase call
childRef.addListenerForSingleValueEvent(valueEventListener);
}
感谢您的回复
答案 0 :(得分:5)
异步回调几乎总是等待等待。特别是你正在使用的忙碌等待。
我发现你的回调代码实际上更清晰了。