duan4523 2014-07-15 02:17
浏览 64

错误在Android登录项目中使用json解析数据

Why with my code below, I am trying to create a login and sign up form using a database with the use of JSON parser but after the run there is an error, the following error in its log:

07-15 01:55:47.400: E/JSON(1661): <HTML></HTML>
07-15 01:55:47.400: E/JSON Parser(1661): Error parsing data org.json.JSONException: Value <HTML>< of type java.lang.String cannot be converted to JSONObject
07-15 01:55:47.400: W/dalvikvm(1661): threadid=1: thread exiting with uncaught exception (group=0xa6289288)
07-15 01:55:47.404: E/AndroidRuntime(1661): FATAL EXCEPTION: main
07-15 01:55:47.404: E/AndroidRuntime(1661): java.lang.NullPointerException
07-15 01:55:47.404: E/AndroidRuntime(1661):     at com.example.androidhive.RegisterActivity$1.onClick(RegisterActivity.java:64)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at android.view.View.performClick(View.java:4084)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at android.view.View$PerformClick.run(View.java:16966)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at android.os.Handler.handleCallback(Handler.java:615)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at android.os.Handler.dispatchMessage(Handler.java:92)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at android.os.Looper.loop(Looper.java:137)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at android.app.ActivityThread.main(ActivityThread.java:4745)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at java.lang.reflect.Method.invokeNative(Native Method)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at java.lang.reflect.Method.invoke(Method.java:511)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
07-15 01:55:47.404: E/AndroidRuntime(1661):     at dalvik.system.NativeStart.main(Native Method)

if there is something wrong with my code, maybe here could help to justify my code, contained mistakes, following full code:

Config.php

<?php

/**
 * Database config variables
 */
define("DB_HOST", "localhost");
define("DB_USER", "root");
define("DB_PASSWORD", "");
define("DB_DATABASE", "android_api");
?>

DB_Connect.php

<?php
class DB_Connect {

    // constructor
    function __construct() {

    }

    // destructor
    function __destruct() {
        // $this->close();
    }

    // Connecting to database
    public function connect() {
        require_once 'include/config.php';
        // connecting to mysql
        $con = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
        // selecting database
        mysql_select_db(DB_DATABASE);

        // return database handler
        return $con;
    }

    // Closing database connection
    public function close() {
        mysql_close();
    }

}

?>

DB_Functions

<?php

class DB_Functions {

    private $db;

    //put your code here
    // constructor
    function __construct() {
        require_once 'DB_Connect.php';
        // connecting to database
        $this->db = new DB_Connect();
        $this->db->connect();
    }

    // destructor
    function __destruct() {

    }

    /**
     * Storing new user
     * returns user details
     */
    public function storeUser($name, $email, $password) {
        $uuid = uniqid('', true);
        $hash = $this->hashSSHA($password);
        $encrypted_password = $hash["encrypted"]; // encrypted password
        $salt = $hash["salt"]; // salt
        $result = mysql_query("INSERT INTO users(unique_id, name, email, encrypted_password, salt, created_at) VALUES('$uuid', '$name', '$email', '$encrypted_password', '$salt', NOW())");
        // check for successful store
        if ($result) {
            // get user details 
            $uid = mysql_insert_id(); // last inserted id
            $result = mysql_query("SELECT * FROM users WHERE uid = $uid");
            // return user details
            return mysql_fetch_array($result);
        } else {
            return false;
        }
    }

    /**
     * Get user by email and password
     */
    public function getUserByEmailAndPassword($email, $password) {
        $result = mysql_query("SELECT * FROM users WHERE email = '$email'") or die(mysql_error());
        // check for result 
        $no_of_rows = mysql_num_rows($result);
        if ($no_of_rows > 0) {
            $result = mysql_fetch_array($result);
            $salt = $result['salt'];
            $encrypted_password = $result['encrypted_password'];
            $hash = $this->checkhashSSHA($salt, $password);
            // check for password equality
            if ($encrypted_password == $hash) {
                // user authentication details are correct
                return $result;
            }
        } else {
            // user not found
            return false;
        }
    }

    /**
     * Check user is existed or not
     */
    public function isUserExisted($email) {
        $result = mysql_query("SELECT email from users WHERE email = '$email'");
        $no_of_rows = mysql_num_rows($result);
        if ($no_of_rows > 0) {
            // user existed 
            return true;
        } else {
            // user not existed
            return false;
        }
    }

    /**
     * Encrypting password
     * @param password
     * returns salt and encrypted password
     */
    public function hashSSHA($password) {

        $salt = sha1(rand());
        $salt = substr($salt, 0, 10);
        $encrypted = base64_encode(sha1($password . $salt, true) . $salt);
        $hash = array("salt" => $salt, "encrypted" => $encrypted);
        return $hash;
    }

    /**
     * Decrypting password
     * @param salt, password
     * returns hash string
     */
    public function checkhashSSHA($salt, $password) {

        $hash = base64_encode(sha1($password . $salt, true) . $salt);

        return $hash;
    }

}

?>

or perhaps an error occurred in my Android project, following its code :

DatabaseHandler.java

import java.util.HashMap;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

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" + ")";
        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();

        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

        // 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();
    }

}

JSONParser

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 + "
");
            }
            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;

    }
}

UserFunction.java

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;

    private static String loginURL = "http://10.0.2.2/android_login_api/";
    private static String registerURL = "http://10.0.2.2/android_login_api/";

    private static String login_tag = "login";
    private static String register_tag = "register";

    // constructor
    public UserFunctions(){
        jsonParser = new JSONParser();
    }

    /**
     * function make Login Request
     * @param email
     * @param password
     * */
    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
        // Log.e("JSON", json.toString());
        return json;
    }

    /**
     * function make Login Request
     * @param name
     * @param email
     * @param password
     * */
    public JSONObject registerUser(String name, String email, String password){
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("tag", register_tag));
        params.add(new BasicNameValuePair("name", name));
        params.add(new BasicNameValuePair("email", email));
        params.add(new BasicNameValuePair("password", password));

        // getting JSON Object
        JSONObject json = jsonParser.getJSONFromUrl(registerURL, params);
        // return json
        return json;
    }

    /**
     * Function get Login status
     * */
    public boolean isUserLoggedIn(Context context){
        DatabaseHandler db = new DatabaseHandler(context);
        int count = db.getRowCount();
        if(count > 0){
            // user logged in
            return true;
        }
        return false;
    }

    /**
     * Function to logout user
     * Reset Database
     * */
    public boolean logoutUser(Context context){
        DatabaseHandler db = new DatabaseHandler(context);
        db.resetTables();
        return true;
    }

}

tolong saya, karena saya sedang mengerjakan tugas akhir di kampus. Login project ini yang membuat saya frustasi, terima kasih

  • 写回答

1条回答 默认 最新

  • drvpv7995 2014-07-15 02:25
    关注

    You had a NullPointerException at RegisterActivity, please post this class so we can help you.

    E/AndroidRuntime(1661): FATAL EXCEPTION: main
    07-15 01:55:47.404: E/AndroidRuntime(1661): java.lang.NullPointerException
    07-15 01:55:47.404: E/AndroidRuntime(1661):     at com.example.androidhive.RegisterActivity$1.onClick(RegisterActivity.java:64)
    
    评论

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