我正在尝试为Android创建一个登录系统。在此登录系统中，当用户登录时，他的详细信息将被添加到sqlite数据库中，因此当他再次打开此应用程序时，他将保持登录状态。目前的问题是，当我在DatabaseHandler类中调用addUser（）方法时，它说不uid的价值。但是当我在logcat中显示json数据时，它会显示uid值。我不知道我在哪里弄错了。请帮我。这是我的代码
LoginActivity
public class LoginActivity extends Activity {
EditText email, password;
Button loginButton, btnLinkToLoginScreen;
TextView login_error;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
email = (EditText)findViewById(R.id.loginEmail);
password = (EditText)findViewById(R.id.loginPassword);
loginButton = (Button)findViewById(R.id.btnLogin);
login_error = (TextView)findViewById(R.id.login_error);
btnLinkToLoginScreen = (Button)findViewById(R.id.btnLinkToLoginScreen);
// JSON Response node names
String KEY_SUCCESS = "success";
String KEY_ERROR = "error";
String KEY_ERROR_MSG = "error_msg";
final String KEY_UID = "uid";
final String KEY_NAME = "name";
final String KEY_EMAIL = "email";
final String KEY_CREATED_AT = "created_at";
loginButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//loginButton.setEnabled(false);
final String useremail = email.getText().toString();
final String userpassword = password.getText().toString();
//Toast.makeText(getBaseContext(), useremail, Toast.LENGTH_LONG).show();
//Log.e("useremail ", useremail);
//Toast.makeText(getBaseContext(), useremail, Toast.LENGTH_LONG).show();
if(!useremail.isEmpty() && !userpassword.isEmpty()) {
UserFunctions userFunction = new UserFunctions();
JSONObject json = userFunction.loginUser(useremail,userpassword);
/*************************************************/
try {
JSONObject obj = json.getJSONObject("user");
Log.e("son", obj.getString(KEY_UID));
} catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
/**************************************************/
try {
if(json != null && json.getString("success") != null) {
login_error.setText("");
String res = json.getString("success");
if(Integer.parseInt(res) == 1) {
//loginButton.setEnabled(true);
//store user in SQLITE
// user successfully logged in
// Store user details in SQLite Database
DatabaseHandler db = new DatabaseHandler(getApplicationContext());
JSONObject json_user = json.getJSONObject("user");
String s = json_user.getString("name") + ", " + json_user.getString("email") + ", " + json.getString("uid") + ", " + json_user.getString("created_at");
Log.e("String: ", s);
// Clear all previous data in database
userFunction.logoutUser(getApplicationContext());
db.addUser(json_user.getString("name"), json_user.getString("email"), json_user.getString(KEY_UID), json_user.getString("created_at"));
//store user in SQLITE ends
//launch dashboard screen
//Intent dashboard = new Intent(getApplicationContext(), DashboardActivity.class);
//Toast.makeText(getBaseContext(), "Success", Toast.LENGTH_LONG).show();
Intent i = new Intent(getApplicationContext(),
DashboardActivity.class);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
finish();
}
} else {
Toast.makeText(getBaseContext(), "Login failed", Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
loginButton.setEnabled(true);
login_error.setText("Enter username and password");
}
}
});
btnLinkToLoginScreen.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i = new Intent(getApplicationContext(),
RegisterActivity.class);
startActivity(i);
finish();
}
});
}
}
这是我的DatabaseHandler类
public class DatabaseHandler extends SQLiteOpenHelper {
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "android_api";
// Login table name
private static final String TABLE_LOGIN = "login";
// Login Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_EMAIL = "email";
private static final String KEY_UID = "uid";
private static final String KEY_CREATED_AT = "created_at";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_LOGIN_TABLE = "CREATE TABLE " + TABLE_LOGIN + "("
+ KEY_ID + " INTEGER PRIMARY KEY,"
+ KEY_NAME + " TEXT,"
+ KEY_EMAIL + " TEXT UNIQUE,"
+ KEY_UID + " TEXT,"
+ KEY_CREATED_AT + " TEXT" + ")";
Log.e("Query: ", CREATE_LOGIN_TABLE);
db.execSQL(CREATE_LOGIN_TABLE);
}
// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LOGIN);
// Create tables again
onCreate(db);
}
/**
* Storing user details in database
* */
public void addUser(String name, String email, String uid, String created_at) {
SQLiteDatabase db = this.getWritableDatabase();
Log.e("Data", uid);
ContentValues values = new ContentValues();
values.put(KEY_NAME, name); // Name
values.put(KEY_EMAIL, email); // Email
values.put(KEY_UID, uid); // Email
values.put(KEY_CREATED_AT, created_at); // Created At
Log.e("Values: ", values.toString());
// Inserting Row
db.insert(TABLE_LOGIN, null, values);
db.close(); // Closing database connection
}
/**
* Getting user data from database
* */
public HashMap<String, String> getUserDetails(){
HashMap<String,String> user = new HashMap<String,String>();
String selectQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// Move to first row
cursor.moveToFirst();
if(cursor.getCount() > 0){
user.put("name", cursor.getString(1));
user.put("email", cursor.getString(2));
user.put("uid", cursor.getString(3));
user.put("created_at", cursor.getString(4));
}
cursor.close();
db.close();
// return user
return user;
}
/**
* Getting user login status
* return true if rows are there in table
* */
public int getRowCount() {
String countQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int rowCount = cursor.getCount();
db.close();
cursor.close();
// return row count
return rowCount;
}
/**
* Re crate database
* Delete all tables and create them again
* */
public void resetTables(){
SQLiteDatabase db = this.getWritableDatabase();
// Delete All Rows
db.delete(TABLE_LOGIN, null, null);
db.close();
}
}
这是logcat
06-01 07:38:43.111: W/KeyCharacterMap(32734): No keyboard for id 0
06-01 07:38:43.111: W/KeyCharacterMap(32734): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
06-01 07:38:43.316: D/CLIPBOARD(32734): Hide Clipboard dialog at Starting input: finished by someone else... !
06-01 07:38:43.316: W/IInputConnectionWrapper(32734): showStatusIcon on inactive InputConnection
06-01 07:38:48.346: D/dalvikvm(32734): GC_EXTERNAL_ALLOC freed 100K, 47% free 3040K/5639K, external 357K/661K, paused 20ms
06-01 07:38:49.521: W/KeyCharacterMap(32734): No keyboard for id 0
06-01 07:38:49.521: W/KeyCharacterMap(32734): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
06-01 07:38:49.831: D/CLIPBOARD(32734): Hide Clipboard dialog at Starting input: finished by someone else... !
06-01 07:38:49.831: W/IInputConnectionWrapper(32734): showStatusIcon on inactive InputConnection
06-01 07:39:49.646: D/dalvikvm(582): GC_CONCURRENT freed 115K, 46% free 3028K/5575K, external 319K/661K, paused 7ms+7ms
06-01 07:39:50.271: E/JSON(582): {"tag":"login","success":1,"error":0,"user":{"name":"Zafar Saleem","uid":"4fc0e87ec8ade4.83917704","email":"zafar@gmail.com","created_at":"2012-05-26 17:28:14","updated_at":null}}
06-01 07:39:50.276: E/son(582): 4fc0e87ec8ade4.83917704
06-01 07:39:50.276: W/System.err(582): org.json.JSONException: No value for uid
06-01 07:39:50.276: W/System.err(582): at org.json.JSONObject.get(JSONObject.java:354)
06-01 07:39:50.296: W/System.err(582): at org.json.JSONObject.getString(JSONObject.java:510)
06-01 07:39:50.296: W/System.err(582): at com.zafar.login.LoginActivity$1.onClick(LoginActivity.java:74)
06-01 07:39:50.296: W/System.err(582): at android.view.View.performClick(View.java:2538)
06-01 07:39:50.296: W/System.err(582): at android.view.View$PerformClick.run(View.java:9152)
06-01 07:39:50.296: W/System.err(582): at android.os.Handler.handleCallback(Handler.java:587)
06-01 07:39:50.296: W/System.err(582): at android.os.Handler.dispatchMessage(Handler.java:92)
06-01 07:39:50.296: W/System.err(582): at android.os.Looper.loop(Looper.java:130)
06-01 07:39:50.301: W/System.err(582): at android.app.ActivityThread.main(ActivityThread.java:3691)
06-01 07:39:50.301: W/System.err(582): at java.lang.reflect.Method.invokeNative(Native Method)
06-01 07:39:50.301: W/System.err(582): at java.lang.reflect.Method.invoke(Method.java:507)
06-01 07:39:50.306: W/System.err(582): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907)
06-01 07:39:50.306: W/System.err(582): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
06-01 07:39:50.306: W/System.err(582): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：2)
更改
String s = json_user.getString("name") + ", " +
json_user.getString("email") + ", " +
json.getString("uid") + ", " +
json_user.getString("created_at");
到
String s = json_user.getString("name") + ", " +
json_user.getString("email") + ", " +
json_user.getString("uid") + ", " +
json_user.getString("created_at");
在LoginActivity.java的第74行