java– 如果已经创建了用户,请更正Firebase的代码位置？

概述我创建了一种方法,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.那么我可以在哪里添加“addUser()”来第

我创建了一种方法,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.
那么我可以在哪里添加“addUser()”来第一次创建所述用户,并确保它永远不会再次调用它,只要用户已经存在？

MainActivity(启动和登录)

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 one rror(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 one rror(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) {}        });    }}

解决方法:

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,调用addUser()函数在FireBase数据库中创建一个新条目.

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,您可能会想到如果用户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.将使用用户的当前信息将值替换为特定路径(如果存在).

现在,如果要检查用户是否已存在于Firebase数据库中,则需要添加此类侦听器.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) {}});

总结

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