Java Android应用程序登录和注册错误
我一直在学习一个关于使用PHP、MySQL开发android登录和注册系统的教程。注册用户时，会将一条记录添加到我的本地数据库（xampp），但应用程序会崩溃。关于这个问题，我也看过类似的问题，但我仍然感到困惑，无法找到解决办法 日志：Java Android应用程序登录和注册错误,java,php,android,mysql,Java,Php,Android,Mysql,我一直在学习一个关于使用PHP、MySQL开发android登录和注册系统的教程。注册用户时，会将一条记录添加到我的本地数据库（xampp），但应用程序会崩溃。关于这个问题，我也看过类似的问题，但我仍然感到困惑，无法找到解决办法 日志： 12-24 14:43:10.875: E/JSON(782): <br /> 12-24 14:43:10.875: E/JSON(782): <b>Deprecated</b>: mysql_connect(): The
12-24 14:43:10.875: E/JSON(782): <br />
12-24 14:43:10.875: E/JSON(782): <b>Deprecated</b>: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in <b>G:\xampp\htdocs\learn2crack_login_api\include\DB_Connect.php</b> on line <b>18</b><br />
12-24 14:43:10.875: E/JSON(782): {"tag":"register","success":1,"error":0,"user":{"fname":"benmid","lname":"muli","email":"benmid@yahoo.com","uname":"benmid14","uid":"549ad0fcaf8052.70050491","created_at":"2014-12-24 14:43:08"}}
12-24 14:43:10.875: E/JSON Parser(782): Error parsing data org.json.JSONException: Value <br of type java.lang.String cannot be converted to JSONObject
12-24 14:43:10.905: D/AndroidRuntime(782): Shutting down VM
12-24 14:43:10.905: W/dalvikvm(782): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
12-24 14:43:10.915: E/AndroidRuntime(782): FATAL EXCEPTION: main
12-24 14:43:10.915: E/AndroidRuntime(782): java.lang.NullPointerException
12-24 14:43:10.915: E/AndroidRuntime(782): at com.learn2crack.Register$ProcessRegister.onPostExecute(Register.java:237)
12-24 14:43:10.915: E/AndroidRuntime(782): at com.learn2crack.Register$ProcessRegister.onPostExecute(Register.java:1)
12-24 14:43:10.915: E/AndroidRuntime(782): at android.os.AsyncTask.finish(AsyncTask.java:631)
12-24 14:43:10.915: E/AndroidRuntime(782): at android.os.AsyncTask.access$600(AsyncTask.java:177)
12-24 14:43:10.915: E/AndroidRuntime(782): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
12-24 14:43:10.915: E/AndroidRuntime(782): at android.os.Handler.dispatchMessage(Handler.java:99)
12-24 14:43:10.915: E/AndroidRuntime(782): at android.os.Looper.loop(Looper.java:137)
12-24 14:43:10.915: E/AndroidRuntime(782): at android.app.ActivityThread.main(ActivityThread.java:5041)
12-24 14:43:10.915: E/AndroidRuntime(782): at java.lang.reflect.Method.invokeNative(Native Method)
12-24 14:43:10.915: E/AndroidRuntime(782): at java.lang.reflect.Method.invoke(Method.java:511)
12-24 14:43:10.915: E/AndroidRuntime(782): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
12-24 14:43:10.915: E/AndroidRuntime(782): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
12-24 14:43:10.915: E/AndroidRuntime(782): at dalvik.system.NativeStart.main(Native Method)
更新：问题已解决。我重新启动了应用程序，现在注册和登录工作正常。谢谢大家的支持 检查json的前几行：
<b>Deprecated</b>: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in <b>G:\xampp\htdocs\learn2crack_login_api\include\DB_Connect.php</b> on line <b>18</b><br /
已弃用：mysql_connect（）：mysql扩展已弃用，将来将被删除：在第18行的G:\xampp\htdocs\learn2crack_login_api\include\DB_connect.php中使用mysqli或PDO，问题似乎是php代码的响应不是应用程序期望的JSON字符串。PHP页面提供的是一个针对mysql\u connect
的弃用警告
，mysql\u connect
被弃用，取而代之的是
或者，您也可以更改
我最初认为您可以将JSON解码调用封装在一个try/catch中，但是在进一步检查代码之后，看起来您已经涵盖了这一点。相反，我意识到可能是代码的其他部分没有处理null
值，如您提供的日志文件中稍微低一点所示。确保您有代码来检查可能的null
值，以防止您的应用程序崩溃，在生产/实时环境中很容易发生这种情况。您从服务器收到的字符串不是有效的JSON
字符串
请参阅下面的字符串：
<b>Deprecated</b>: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in <b>G:\xampp\htdocs\learn2crack_login_api\include\DB_Connect.php</b> on line <b>18</b><br />
已弃用：mysql_connect（）：mysql扩展已弃用，将来将被删除：在第18行的G:\xampp\htdocs\learn2crack_login_api\include\DB_connect.php中使用mysqli或PDO
这意味着，您应该切换到mysqli或PDO，因为mysql扩展已经贬值
替代解决方案：
关闭服务器上的所有PHP
错误和警告。好主意提及已准备好的语句，他拥有的当前代码看起来是为SQL注入打开的。它不仅看起来很脆弱，而且很容易受到攻击。：）Hi Gerifield我关闭了错误消息，现在我的屏幕停留在“联系服务器，注册”上。我得到以下错误：12-24 15:33:34.971:E/JSON（863）：{“tag”：“register”，“success”：0，“error”：1，“error_msg”：“registarion中发生了JSON错误”}JSON本身现在是正确的。这是另一个错误和问题。连接正常，可以检查解析器。您不需要关闭所有错误和警告，只需关闭弃用消息即可。可以，但在开发服务器上，而不是在实时服务器上。改为在每日日志文件中记录错误和警告。嗨，MTahir，我关闭了错误消息，现在我的屏幕停留在“联系服务器，注册”上。我得到以下错误：12-24 15:33:34.971:E/JSON（863）：{“tag”：“register”，“success”：0，“error”：1，“error_msg”：“registarion中发生JSON错误”}
<?php
/**
* Database config variables
*/
define("DB_HOST", "127.0.0.1");
define("DB_USER", "root");
define("DB_PASSWORD", "");
define("DB_DATABASE", "learn2crack_login_api");
?>
package com.learn2crack.library;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import java.util.HashMap;
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 = "cloud_contacts";
// 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_FIRSTNAME = "fname";
private static final String KEY_LASTNAME = "lname";
private static final String KEY_EMAIL = "email";
private static final String KEY_USERNAME = "uname";
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_FIRSTNAME + " TEXT,"
+ KEY_LASTNAME + " TEXT,"
+ KEY_EMAIL + " TEXT UNIQUE,"
+ KEY_USERNAME + " TEXT,"
+ KEY_UID + " TEXT,"
+ KEY_CREATED_AT + " TEXT" + ")";
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 fname, String lname, String email, String uname, String uid, String created_at) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_FIRSTNAME, fname); // FirstName
values.put(KEY_LASTNAME, lname); // LastName
values.put(KEY_EMAIL, email); // Email
values.put(KEY_USERNAME, uname); // UserName
values.put(KEY_UID, uid); // Email
values.put(KEY_CREATED_AT, created_at); // Created At
// 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("fname", cursor.getString(1));
user.put("lname", cursor.getString(2));
user.put("email", cursor.getString(3));
user.put("uname", cursor.getString(4));
user.put("uid", cursor.getString(5));
user.put("created_at", cursor.getString(6));
}
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();
}
}
package com.learn2crack.library;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url, List<NameValuePair> params) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
Log.e("JSON", json);
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
package com.learn2crack.library;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONObject;
import android.content.Context;
public class UserFunctions {
private JSONParser jsonParser;
//URL of the PHP API
private static String loginURL = "http://10.0.2.2/learn2crack_login_api/";
private static String registerURL = "http://10.0.2.2/learn2crack_login_api/";
private static String forpassURL = "http://10.0.2.2/learn2crack_login_api/";
private static String chgpassURL = "http://10.0.2.2/learn2crack_login_api/";
private static String login_tag = "login";
private static String register_tag = "register";
private static String forpass_tag = "forpass";
private static String chgpass_tag = "chgpass";
// constructor
public UserFunctions(){
jsonParser = new JSONParser();
}
/**
* Function to Login
**/
public JSONObject loginUser(String email, String password){
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("tag", login_tag));
params.add(new BasicNameValuePair("email", email));
params.add(new BasicNameValuePair("password", password));
JSONObject json = jsonParser.getJSONFromUrl(loginURL, params);
return json;
}
/**
* Function to change password
**/
public JSONObject chgPass(String newpas, String email){
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("tag", chgpass_tag));
params.add(new BasicNameValuePair("newpas", newpas));
params.add(new BasicNameValuePair("email", email));
JSONObject json = jsonParser.getJSONFromUrl(chgpassURL, params);
return json;
}
/**
* Function to reset the password
**/
public JSONObject forPass(String forgotpassword){
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("tag", forpass_tag));
params.add(new BasicNameValuePair("forgotpassword", forgotpassword));
JSONObject json = jsonParser.getJSONFromUrl(forpassURL, params);
return json;
}
/**
* Function to Register
**/
public JSONObject registerUser(String fname, String lname, String email, String uname, String password){
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("tag", register_tag));
params.add(new BasicNameValuePair("fname", fname));
params.add(new BasicNameValuePair("lname", lname));
params.add(new BasicNameValuePair("email", email));
params.add(new BasicNameValuePair("uname", uname));
params.add(new BasicNameValuePair("password", password));
JSONObject json = jsonParser.getJSONFromUrl(registerURL,params);
return json;
}
/**
* Function to logout user
* Resets the temporary data stored in SQLite Database
* */
public boolean logoutUser(Context context){
DatabaseHandler db = new DatabaseHandler(context);
db.resetTables();
return true;
}
}
12-24 15:33:34.971: E/JSON(863): {"tag":"register","success":0,"error":1,"error_msg":"JSON Error occured in Registartion"}
<b>Deprecated</b>: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in <b>G:\xampp\htdocs\learn2crack_login_api\include\DB_Connect.php</b> on line <b>18</b><br /
<b>Deprecated</b>: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in <b>G:\xampp\htdocs\learn2crack_login_api\include\DB_Connect.php</b> on line <b>18</b><br />