我创建了一种方法，用于在用户登录后获取用户的facebook数据，并在我的firebase数据库中为他们创建“用户”。此方法addUser（）也为所述用户创建和设置变量。但我必须保留方法，登录，所以它创建我的变量，然后注释方法以供将来测试，或者它将重置所有值。 那么，只要用户已经存在，我可以在哪里添加“addUser（）”来第一次创建所述用户，并确保它再也不会再次调用它？
MainActivity（开始和登录）
public class MainActivity extends AppCompatActivity {
CallbackManager callbackManager;
ShareDialog shareDialog;
LoginButton login;
ProfilePictureView profile;
Dialog details_dialog;
TextView details_txt;
JSONObject response;
/* Used to track user logging in/out off Facebook */
private AccessTokenTracker mFacebookAccessTokenTracker;
/* A reference to the Firebase */
private Firebase mFirebaseRef;
/* A reference to the Firebase */
private Firebase userRef;
/* Data from the authenticated user */
public static AuthData mAuthData;
/* Listener for Firebase session changes */
private Firebase.AuthStateListener mAuthStateListener;
public static String uName = null;
public static String uEmail = null;
public static String uUrl = null;
public static int mTokens = 50;
public static String uID = null;
public static int getLiveTokens() {
return liveTokens;
}
public static void setLiveTokens(int liveTokens) {
MainActivity.liveTokens = liveTokens;
}
public static int liveTokens = 0;
public static int getLiveSpins() {
return liveSpins;
}
public static void setLiveSpins(int liveSpins) {
MainActivity.liveSpins = liveSpins;
}
public static int liveSpins = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mFirebaseRef = new Firebase("https://<url>.firebaseio.com/");
callbackManager = CallbackManager.Factory.create();
login = (LoginButton) findViewById(R.id.login_button);
profile = (ProfilePictureView) findViewById(R.id.picture);
shareDialog = new ShareDialog(this);
login.setReadPermissions("public_profile email");
details_dialog = new Dialog(this);
details_dialog.setContentView(R.layout.dialog_details);
details_dialog.setTitle("Details");
details_txt = (TextView) details_dialog.findViewById(R.id.details);
getLoginDetails(login);
mFacebookAccessTokenTracker = new AccessTokenTracker() {
@Override
protected void onCurrentAccessTokenChanged(AccessToken oldAccessToken, AccessToken currentAccessToken) {
//Log.i(Tag, "Facebook.AccessTokenTracker.OnCurrentAccessTokenChanged");
// Toast.makeText(getApplicationContext(), "FBAccessTokenChange", Toast.LENGTH_LONG).show();
MainActivity.this.onFacebookAccessTokenChange(currentAccessToken);
}
};
if (AccessToken.getCurrentAccessToken() != null) {
RequestData();
getLoginDetails(login);
getUserInfo();
Toast.makeText(getApplicationContext(), "Already Logged In", Toast.LENGTH_LONG).show();
}
login.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (AccessToken.getCurrentAccessToken() != null) {
profile.setProfileId(null);
}
}
});
mAuthStateListener = new Firebase.AuthStateListener() {
@Override
public void onAuthStateChanged(AuthData authData) {
// mAuthProgressDialog.hide();
setAuthenticatedUser(authData);
}
};
/* Check if the user is authenticated with Firebase already. If this is the case we can set the authenticated
* user and hide hide any login buttons */
mFirebaseRef.addAuthStateListener(mAuthStateListener);
}
public void addUser() {
this.uID = mAuthData.getUid();
Toast.makeText(getApplicationContext(), "Setting Up User Account", Toast.LENGTH_LONG).show();
Firebase rootRef = new Firebase("https://<url>.firebaseio.com/users/");
Firebase userRef = rootRef.child(mAuthData.getUid() + "/");
userRef.child("name").setValue(mAuthData.getProviderData().get("displayName"));
userRef.child("provider").setValue(mAuthData.getProvider());
userRef.child("email").setValue(mAuthData.getProviderData().get("email"));
userRef.child("tokens").setValue("100");
userRef.child("spins").setValue("100");
userRef.child("totalspins").setValue("0");
userRef.child("topwin").setValue("0");
}
protected void getLoginDetails(LoginButton login){
login.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
@Override
public void onSuccess(LoginResult login_Result) {
getUserInfo();
}
@Override
public void onCancel() {
}
@Override
public void onError(FacebookException exception) {
}
});
}
// LoginResult login_result
protected void getUserInfo() {
// LoginResult login_result.getAccessToken()
GraphRequest data_request = GraphRequest.newMeRequest(AccessToken.getCurrentAccessToken(), new GraphRequest.GraphJSONObjectCallback() {
@Override
public void onCompleted(JSONObject json_object, GraphResponse response) {
Intent intent = new Intent(MainActivity.this, HomeActivity.class);
intent.putExtra("jsondata", json_object.toString());
intent.putExtra("Uid", uID);
startActivity(intent);
}
});
Bundle permission_param = new Bundle();
permission_param.putString("fields", "id,name,email,picture.width(120).height(120)");
data_request.setParameters(permission_param);
data_request.executeAsync();
}
public void RequestData() {
GraphRequest request = GraphRequest.newMeRequest(AccessToken.getCurrentAccessToken(), new GraphRequest.GraphJSONObjectCallback() {
@Override
public void onCompleted(JSONObject object, GraphResponse response) {
JSONObject json = response.getJSONObject();
try {
if (json != null) {
String text = "<b>Name :</b> " + json.getString("name") + "<br><br><b>Email :</b> " + json.getString("email") + "<br><br><b>Profile link :</b> " + json.getString("link");
details_txt.setText(Html.fromHtml(text));
profile.setProfileId(json.getString("id"));
uName = json.getString("name");
uEmail = json.getString("email");
uUrl = json.getString("id");
}
} catch (JSONException e) {
e.printStackTrace();
}
}
});
Bundle parameters = new Bundle();
parameters.putString("fields", "id,name,link,email,picture");
request.setParameters(parameters);
request.executeAsync();
}
/**
* This method will attempt to authenticate a user to firebase given an oauth_token (and other
* necessary parameters depending on the provider)
*/
private void authWithFirebase(final String provider, Map<String, String> options) {
if (options.containsKey("error")) {
showErrorDialog(options.get("error"));
} else {
//mAuthProgressDialog.show();
// if the provider is not twitter, we just need to pass in the oauth_token
mFirebaseRef.authWithOAuthToken(provider, options.get("oauth_token"), new AuthResultHandler(provider));
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
callbackManager.onActivityResult(requestCode, resultCode, data);
}
private void setAuthenticatedUser(AuthData authData) {
if (authData != null) {
/* show a provider specific status text */
String name = null;
if (authData.getProvider().equals("facebook")) {
name = (String) authData.getProviderData().get("displayName");
} else if (authData.getProvider().equals("anonymous")
|| authData.getProvider().equals("password")) {
name = authData.getUid();
} else {
Toast.makeText(getApplicationContext(), "invalid provider", Toast.LENGTH_LONG).show();
}
if (name != null) {
//success
// Toast.makeText(getApplicationContext(), "Log " + name + " (" + authData.getProvider() + ")", Toast.LENGTH_LONG).show();
}
} else {
}
// Firebase Authenticated
this.mAuthData = authData;
MainActivity.uID = mAuthData.getUid();
//addUser();
/* invalidate options menu to hide/show the logout button */
supportInvalidateOptionsMenu();
}
/**
* Show errors to users
*/
private void showErrorDialog(String message) {
new AlertDialog.Builder(this)
.setTitle("Error")
.setMessage(message)
.setPositiveButton(android.R.string.ok, null)
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
}
private class AuthResultHandler implements Firebase.AuthResultHandler {
private final String provider;
public AuthResultHandler(String provider) {
this.provider = provider;
}
@Override
public void onAuthenticated(AuthData authData) {
// mAuthProgressDialog.hide();
// Toast.makeText(getApplicationContext(), "Auth Success", Toast.LENGTH_LONG).show();
// Toast.makeText(getApplicationContext(), authData.getUid(), Toast.LENGTH_LONG).show();
// createUser();
setAuthenticatedUser(authData);
String mEmail = authData.getUid();
// uID = authData.getUid();
String mProvide = mAuthData.getProvider();
}
@Override
public void onAuthenticationError(FirebaseError firebaseError) {
//mAuthProgressDialog.hide();
showErrorDialog(firebaseError.toString());
}
}
public void createUser(){
Firebase rootRef = new Firebase("https://<url>.firebaseio.com/");
Firebase userRef = rootRef.child("users").child(mAuthData.getUid());
userRef.child("provider").setValue(mAuthData.getProvider());
userRef.child("provider").setValue(mAuthData.getProviderData().get("displayName)"));
rootRef.createUser(mAuthData.getProviderData().get("email").toString(), mAuthData.getProviderData().get("id").toString(), new Firebase.ValueResultHandler<Map<String, Object>>() {
@Override
public void onSuccess(Map<String, Object> result){
Toast.makeText(getApplicationContext(), "Yes-UID=" + result.get("Uid") , Toast.LENGTH_LONG).show();
}
@Override
public void onError(FirebaseError firebaseError){
Toast.makeText(getApplicationContext(), "Not Created", Toast.LENGTH_LONG).show();
}
});
}
private void logout() {
if (this.mAuthData != null) {
/* logout of Firebase */
mFirebaseRef.unauth();
/* Logout of any of the Frameworks. This step is optional, but ensures the user is not logged into
* Facebook/Google+ after logging out of Firebase. */
if (this.mAuthData.getProvider().equals("facebook")) {
/* Logout from Facebook */
LoginManager.getInstance().logOut();
}
/* Update authenticated user and show login buttons */
setAuthenticatedUser(null);
}
}
@Override
protected void onResume() {
super.onResume();
AppEventsLogger.activateApp(this);
}
@Override
protected void onPause() {
super.onPause();
AppEventsLogger.deactivateApp(this);
}
/* ************************************
* FACEBOOK *
**************************************
*/
private void onFacebookAccessTokenChange(AccessToken token) {
if (token != null) {
//mAuthProgressDialog.show();
mFirebaseRef.authWithOAuthToken("facebook", token.getToken(), new AuthResultHandler("facebook"));
} else {
// Logged out of Facebook and currently authenticated with Firebase using Facebook, so do a logout
if (this.mAuthData != null && this.mAuthData.getProvider().equals("facebook")) {
mFirebaseRef.unauth();
setAuthenticatedUser(null);
}
}
}
public static int getmTokens() {
return getLiveTokens();
}
public static void setmTokens(int mTokens) {
MainActivity.mTokens = mTokens;
}
public static void takemTokens(int mTokens) {
MainActivity.mTokens -= mTokens;
}
public static void givemTokens(final int ttokens) {
//MainActivity.mTokens += tokens;
// TODO
// if (ttokens > MainActivity.getmTopWin()){
// MainActivity.setmTopWin(ttokens);
//}
Firebase ref = new Firebase("https://<url>.firebaseio.com/users/" + MainActivity.uID + "/");
final Firebase tokensRef = ref.child("tokens");
tokensRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
int iii = new Integer(dataSnapshot.getValue().toString());
iii += ttokens;
tokensRef.setValue(iii);
setLiveTokens(iii);
checkmTopWin(ttokens);
}
@Override
public void onCancelled(FirebaseError firebaseError) {
}
});
//tokensRef.removeEventListener(MainActivity);
}
public static int mSpins = 30;
public static int getmSpins() {
return getLiveSpins();
}
public static void setmSpins(int mspins) {
MainActivity.mSpins = mspins;
}
public static void takemSpins(final int mspins) {
Firebase ref = new Firebase("https://<url>.firebaseio.com/users/" + MainActivity.uID + "/");
final Firebase tokensRef = ref.child("spins");
tokensRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
int i = Integer.valueOf(dataSnapshot.getValue().toString());
i -= mspins;
tokensRef.setValue(i);
setLiveSpins(i);
}
@Override
public void onCancelled(FirebaseError firebaseError) {}
});
}
public static void givemSpins(final int mspins){
Firebase ref = new Firebase("https://<url>.firebaseio.com/users/" + MainActivity.uID + "/");
final Firebase tokensRef = ref.child("spins");
tokensRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
int i = Integer.valueOf(dataSnapshot.getValue().toString());
i += mspins;
tokensRef.setValue(i);
}
@Override
public void onCancelled(FirebaseError firebaseError) {}
});
}
public static int slotVari = 0;
public static int getSlotVari() {
return slotVari;
}
public static void setSlotVari(int slotVari) {
MainActivity.slotVari = slotVari;
}
public static int mTotalSpins;
public static int getmTotalSpins() {
return mTotalSpins;
}
public static void setmTotalSpins(int mTotalSpins) {
MainActivity.mTotalSpins = mTotalSpins;
}
public static void incmTotalSpins(){
Firebase ref = new Firebase("https://<url>.firebaseio.com/users/" + MainActivity.uID + "/");
final Firebase tokensRef = ref.child("totalspins");
tokensRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
int i = Integer.valueOf(dataSnapshot.getValue().toString());
i++;
tokensRef.setValue(i);
}
@Override
public void onCancelled(FirebaseError firebaseError) {}
});
MainActivity.mTotalSpins++;
}
public static int mTopWin;
public static int getmTopWin() {
return mTopWin;
}
public static void setmTopWin(int mTopWin) {
Firebase ref = new Firebase("https://<url>.firebaseio.com/users/" + MainActivity.uID + "/");
Firebase tokensRef = ref.child("topwin");
tokensRef.setValue(mTopWin);
MainActivity.mTopWin = mTopWin;
}
public static void checkmTopWin(final int mTokensWon) {
Firebase ref = new Firebase("https://<url>.firebaseio.com/users/" + MainActivity.uID + "/");
final Firebase tokensRef = ref.child("topwin");
tokensRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
int i = Integer.valueOf(dataSnapshot.getValue().toString());
if (i < mTokensWon){
tokensRef.setValue(mTokensWon);
}
}
@Override
public void onCancelled(FirebaseError firebaseError) {}
});
}
}
答案 0 :(得分：7)
您需要设置FIRST_LAUNCH等首选项，并在每次用户登录时检查其是否为真。首次启动应用程序时，将找不到FIRST_LAUNCH首选项。因此，请调用addUser()函数在FireBase数据库中创建新条目。
SharedPreferences pref = getSharedPreferences(Constants.ApplicationTag, Activity.MODE_PRIVATE);
if (!pref.contains(Constants.FIRST_LAUNCH)) {
addUser();
pref.edit().putBoolean(Constants.FIRST_LAUNCH, true).commit();
}
因此，您可能会考虑用户是否卸载您的应用程序然后重新安装它，首选项将会消失，并且将再次调用addUser()函数。没问题，只要child属性的路径相同，您就不会获得新的Firebase条目。这些值将替换为特定路径（如果存在），并包含用户的当前信息。
现在，如果您想检查您的用户是否已存在于Firebase数据库中，您需要添加这样的监听器。我附上了一个代码示例，以便更好地理解。
Firebase rootRef = new Firebase("https://<url>.firebaseio.com/users/");
Firebase userRef = rootRef.child(mAuthData.getUid() + "/");
userRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
// User exists. Do nothing
} else addUser();
}
@Override
public void onCancelled(FirebaseError firebaseError) {}
});