我想我在Firebase或Android Studio中发现了一个错误 我将代码（图1）添加到ChatActivity.java，我收到错误：
（ com.google.firebase.database.DatabaseException：无法将java.lang.String类型的值转换为int ）
但是当我删除代码（图1）时，我仍然会收到包含（图2）的每个脚本中的消息。
为什么现在将它删除后将其引用为整数而不是字符串？
fig1（代码）
private FirebaseDatabase database;
private DatabaseReference myConnectionsRef;
...
protected void onCreate(Bundle savedInstanceState) {...` database = FirebaseDatabase.getInstance();
myConnectionsRef = database.getReference("users/" + FirebaseAuth.getInstance().getCurrentUser().getUid() + "/n_newmessages_c");` fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (input.getText().toString().trim().equals("")) {
Toast.makeText(ChatActivity.this, "Please enter some texts!", Toast.LENGTH_SHORT).show();
} else {.... myConnectionsRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(com.google.firebase.database.DataSnapshot dataSnapshot) {
try{
notifMcount = (long) dataSnapshot.getValue();
Log.e(TAG, "onDataChange: NOTIFICATION COUNT MESSAGES--------------------- = " + notifMcount );
long newNotifAmount = notifMcount + 1;
myRef.child(getString(R.string.dbname_users))
.child(mUser.getUser_id())
.child("n_newmessages_c")
.setValue(newNotifAmount);
}catch (NullPointerException e){
Log.e(TAG, "onDataChange: NullPointerException" + e.getMessage() );
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
fig2（code）（来自MessengerFriendsOnline.java）
private void updateUserslist(){
Log.d(TAG, "updateUsersList: updating users list");
mAdapter = new MessagesListAdapter(getActivity(), R.layout.layout_friend_listitem, mUserList);
mListView.setAdapter(mAdapter);
mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Log.d(TAG, "onItemClick: selected user: " + mUserList.get(position).toString());
//navigate to profile activity
Intent intent = new Intent(getActivity(), ChatActivity.class);
intent.putExtra(getString(R.string.intent_user), mUserList.get(position));
startActivity(intent);
}
});
}
private void updateFriendsList(){
Log.d(TAG, "getPhotos: getting Friend(s)");
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
for(int i = 0; i < mFriends.size(); i++){
final int count = i;
Query query = reference
.child(getString(R.string.dbname_users))
.orderByChild(getString(R.string.field_user_id))
.equalTo(mFriends.get(i));
query.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot singleSnapshot : dataSnapshot.getChildren()){
//boolean is_Online = singleSnapshot.getValue(User.class).isOnline();
// Log.w(TAG, "onDataChange: FRIEND IS ONLINE ********************** = " + is_Online );
//if(is_Online == true) {
mUserList.add(singleSnapshot.getValue(User.class));
//}
}
if(count >= mFriends.size() - 1){
updateUserslist();
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}
private void getFriends(){
Log.d(TAG, "getFollowing: searching for FRIENDS **************************************");
mFriends.clear();
mUserList.clear();
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
Query query = reference
.child(getString(R.string.dbname_friends))
.child(FirebaseAuth.getInstance().getCurrentUser().getUid());
query.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot singleSnapshot : dataSnapshot.getChildren()) {
Log.d(TAG, "onDataChange: found friend----------------**: " + singleSnapshot.getValue(User.class).toString());
mFriends.add(singleSnapshot.child(getString(R.string.field_user_id)).getValue().toString());
Log.d(TAG, "onDataChange: Freinds user id: " + mFriends.toString() );
}
//get the photos
updateFriendsList();
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
ChatActivity.java
public class ChatActivity extends AppCompatActivity {
private static final String TAG = "ChatActivity";
private static final int SIGN_IN_REQUEST_CODE = 111;
private FirebaseListAdapter<ChatMessage> adapter;
private ListView listView;
private String loggedInUserName = "";
private int messagesCount = 0;
private DatabaseReference myRef;
private long notifMcount;
Map data;
private FirebaseDatabase database;
private DatabaseReference myConnectionsRef;
private User mUser;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_chat);
myRef = FirebaseDatabase.getInstance().getReference();
//find views by Ids
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
final EditText input = (EditText) findViewById(R.id.input);
listView = (ListView) findViewById(R.id.list);
data = new HashMap();
try {
mUser = getUserFromBundle();
//init();
}catch (NullPointerException e){
Log.e(TAG, "NullPointerException: " + e.getMessage() );
Toast.makeText(this, "Something went wrong", Toast.LENGTH_SHORT).show();
getSupportFragmentManager().popBackStack();
}
if (FirebaseAuth.getInstance().getCurrentUser() == null) {
// Start sign in/sign up activity
startActivityForResult(AuthUI.getInstance()
.createSignInIntentBuilder()
.build(), SIGN_IN_REQUEST_CODE);
} else {
// User is already signed in, show list of messages
showAllOldMessages();
}
database = FirebaseDatabase.getInstance();
myConnectionsRef = database.getReference("users/" + FirebaseAuth.getInstance().getCurrentUser().getUid() + "/n_newmessages_c");
Log.d(TAG, "onCreate: USER SELECT TO CHAT WITH********************** " + mUser.getUser_id());
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (input.getText().toString().trim().equals("")) {
Toast.makeText(ChatActivity.this, "Please enter some texts!", Toast.LENGTH_SHORT).show();
} else {
Log.d(TAG, "onDataChange: Messages -- BEFORE 2 *******************************" + messagesCount);
myRef.child(getString(R.string.dbname_messages))
.child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child(mUser.getUser_id())
.child("Chat")
.push()
.setValue(new ChatMessage(input.getText().toString(),
FirebaseAuth.getInstance().getCurrentUser().getEmail(),
FirebaseAuth.getInstance().getCurrentUser().getUid())
);
Log.d(TAG, "onDataChange: Messages AFTER 1 --- *******************************" + messagesCount);
myRef.child(getString(R.string.dbname_messages))
.child(mUser.getUser_id())
.child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child("Chat")
.push()
.setValue(new ChatMessage(input.getText().toString(),
FirebaseAuth.getInstance().getCurrentUser().getEmail(),
FirebaseAuth.getInstance().getCurrentUser().getUid())
);
myRef.child(getString(R.string.dbname_messages))
.child(mUser.getUser_id())
.child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child("ChatSettings")
.child("new_message_n")
.setValue(true);
myConnectionsRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(com.google.firebase.database.DataSnapshot dataSnapshot) {
try{
notifMcount = (long) dataSnapshot.getValue();
Log.e(TAG, "onDataChange: NOTIFICATION COUNT MESSAGES--------------------- = " + notifMcount );
long newNotifAmount = notifMcount + 1;
myRef.child(getString(R.string.dbname_users))
.child(mUser.getUser_id())
.child("n_newmessages_c")
.setValue(newNotifAmount);
}catch (NullPointerException e){
Log.e(TAG, "onDataChange: NullPointerException" + e.getMessage() );
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
long newNotifAmount = notifMcount + 1;
myRef.child(getString(R.string.dbname_users))
.child(mUser.getUser_id())
.child("n_newmessages_c")
.setValue(newNotifAmount);
Log.d(TAG, "onDataChange: Messages AFTER 2 --- *******************************" + messagesCount);
}
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == SIGN_IN_REQUEST_CODE) {
if (resultCode == RESULT_OK) {
Toast.makeText(this, "Signed in successful!", Toast.LENGTH_LONG).show();
showAllOldMessages();
} else {
Toast.makeText(this, "Sign in failed, please try again later", Toast.LENGTH_LONG).show();
finish();
}
}
}
private void showAllOldMessages() {
loggedInUserName = FirebaseAuth.getInstance().getCurrentUser().getUid();
Log.d("Main", "user id: " + loggedInUserName);
adapter = new MessageAdapter(this, ChatMessage.class, R.layout.item_in_message,
FirebaseDatabase.getInstance().getReference().child(getString(R.string.dbname_messages))
.child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child(mUser.getUser_id())
.child("Chat"));
listView.setAdapter(adapter);
}
private User getUserFromBundle(){
Bundle bundle = getIntent().getExtras();
if(bundle != null){
return bundle.getParcelable(getString(R.string.intent_user));
}else{
return null;
}
}
@Override
public void onStart() {
super.onStart();
myRef.child(getString(R.string.dbname_messages))
.child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child(mUser.getUser_id())
.child("ChatSettings")
.child("new_message_n")
.setValue(false);
}
@Override
public void onStop() {
super.onStop();
myRef.child(getString(R.string.dbname_messages))
.child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child(mUser.getUser_id())
.child("ChatSettings")
.child("new_message_n")
.setValue(false);
}
错误讯息：
12-02 18:04:39.200 19657-19657/com.example.user.someapp E/MessengerMessagesFragme: getFollowing: searching for FRIENDS **************************************
12-02 18:04:40.106 3829-530/? E/ctxmgr: [AppIntervalImpl]closeInterval: ongoing
12-02 18:04:41.046 1472-1561/? E/TaskPersister: File error accessing recents directory (directory doesn't exist?).
12-02 18:04:49.056 1472-1485/? E/memtrack: Couldn't load memtrack module
12-02 18:05:00.002 1472-1485/? E/memtrack: Couldn't load memtrack module
12-02 18:05:06.403 1472-1485/? E/memtrack: Couldn't load memtrack module
12-02 18:05:06.419 1472-1485/? E/memtrack: Couldn't load memtrack module
12-02 18:05:09.294 1472-1485/? E/memtrack: Couldn't load memtrack module
12-02 18:05:09.298 1472-1489/? E/BatteryStatsService: modem info is invalid: ModemActivityInfo{ mTimestamp=0 mSleepTimeMs=0 mIdleTimeMs=0 mTxTimeMs[]=[0, 0, 0, 0, 0] mRxTimeMs=0 mEnergyUsed=0}
12-02 18:05:11.297 19657-19657/com.example.user.someapp E/libEGL: call to OpenGL ES API with no current context (logged once per thread)
12-02 18:05:11.408 19657-19657/com.example.user.someapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.user.someapp, PID: 19657
com.google.firebase.database.DatabaseException: Failed to convert a value of type java.lang.String to int
at com.google.android.gms.internal.zzekp.zzb(Unknown Source:180)
at com.google.android.gms.internal.zzekp.zza(Unknown Source:312)
at com.google.android.gms.internal.zzekp.zzb(Unknown Source:0)
at com.google.android.gms.internal.zzekq.zze(Unknown Source:153)
at com.google.android.gms.internal.zzekp.zzb(Unknown Source:772)
at com.google.android.gms.internal.zzekp.zza(Unknown Source:0)
at com.google.firebase.database.DataSnapshot.getValue(Unknown Source:10)
at com.example.user.someapp.MessengerFriendsOnline$2.onDataChange(MessengerFriendsOnline.java:146)
at com.google.firebase.database.zzp.onDataChange(Unknown Source:7)
at com.google.android.gms.internal.zzeex.zza(Unknown Source:13)
at com.google.android.gms.internal.zzegs.zzbwg(Unknown Source:2)
at com.google.android.gms.internal.zzegy.run(Unknown Source:65)
at android.os.Handler.handleCallback(Handler.java:789)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
答案 0 :(得分：2)
首先，这是从DataSnapshot获取Long的正确方法
notifMcount = dataSnapshot.getValue(Long.class)
其次，您的User类的数据类型错误
mUserList.add(singleSnapshot.getValue(User.class));
Something是一个String，但实际上是Firebase中的一个int。查看您的代码，并将字符串字段与Firebase中没有引号的值进行比较