Android：如何將Java.String轉換為JSONObject

Question

我剛剛開始使用Android Studio進行編碼，但遇到一個我找不到解決方案的問題。 我嘗試創建一個登錄/注冊活動，並且在注冊器正常運行時，登錄使我很難解決下一個錯誤：

"Json error :Value<br><table of type java.lang.String cannot be converted to JSONObject"

在調試時，我設法找到問題的根源，並將代碼粘貼在這里：

 StringRequest strReq = new StringRequest(Method.POST,
            AppConfig.URL_LOGIN, new Response.Listener<String>() {

        @Override
        public void onResponse(String response) {
            Log.d(TAG, "Login Response: " + response.toString());
            hideDialog();

            try {

                **JSONObject jObj = new JSONObject(response);**
                boolean error = jObj.getBoolean("error");

                // Check for error node in json
                if (!error) {
                    // user successfully logged in
                    // Create login session
                    session.setLogin(true);

                    // Now store the user in SQLite
                    String uid = jObj.getString("uid");

                    JSONObject user = jObj.getJSONObject("user");
                    String name = user.getString("name");
                    String email = user.getString("email");
                    String created_at = user.getString("created_at");

                    // Inserting row in users table
                    db.addUser(name, email, uid, created_at);

                    // Launch main activity
                    Intent intent = new Intent(LoginActivity.this,
                            MainActivity.class);
                    startActivity(intent);
                    finish();
                } else {
                    // Error in login. Get the error message
                    String errorMsg = jObj.getString("error_msg");
                    Toast.makeText(getApplicationContext(),
                            errorMsg, Toast.LENGTH_LONG).show();
                }
            } catch (JSONException e) {
                // JSON error
                e.printStackTrace();
                Toast.makeText(getApplicationContext(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
            }

        }
    }, new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            Log.e(TAG, "Login Error: " + error.getMessage());
            Toast.makeText(getApplicationContext(),
                    error.getMessage(), Toast.LENGTH_LONG).show();
            hideDialog();
        }
    }) {

        @Override
        protected Map<String, String> getParams() {
            // Posting parameters to login url
            Map<String, String> params = new HashMap<String, String>();
            params.put("email", email);
            params.put("password", password);

            return params;
        }

    };

調試器將我指向標有** ... **的行。

如果有人可以幫助我找到解決方案，我將不勝感激。 （如果需要更多代碼或類似的代碼，請告訴我，然后加上）。

順便說一句，我正在使用具有MYSQL版本的000webhost。 5.1。 數據庫連接良好並且可以正常工作（經過注冊測試，效果很好）。

我在DDMS上遇到的錯誤，

    11-29 17:42:04.036: D/RegisterActivity(2188): Login Response: <br><table border='1' cellpadding='2' bgcolor='#FFFFDF' bordercolor='#E8B900' align='center'><tr><td><font face='Arial' size='1' color='#000000'><b>PHP Error Message</b></font></td></tr></table><br />
11-29 17:42:04.036: D/RegisterActivity(2188): <b>Fatal error</b>:  Call to undefined method mysqli_stmt::get_result() in <b>/home/a4085630/public_html/include/DB_Functions.php</b> on line <b>59</b><br />
11-29 17:42:04.036: D/RegisterActivity(2188): <br><table border='1' cellpadding='2' bgcolor='#FFFFDF' bordercolor='#E8B900' align='center'><tr><td><div align='center'><a href='http://www.000webhost.com/'><font face='Arial' size='1' color='#000000'>Free Web Hosting</font></a></div></td></tr></table>
11-29 17:42:04.059: E/Surface(2188): getSlotFromBufferLocked: unknown buffer: 0xb3f967c0
11-29 17:42:04.065: W/System.err(2188): org.json.JSONException: Value <br><table of type java.lang.String cannot be converted to JSONObject
11-29 17:42:04.065: W/System.err(2188):     at org.json.JSON.typeMismatch(JSON.java:111)
11-29 17:42:04.065: W/System.err(2188):     at org.json.JSONObject.<init>(JSONObject.java:160)
11-29 17:42:04.065: W/System.err(2188):     at org.json.JSONObject.<init>(JSONObject.java:173)
11-29 17:42:04.065: W/System.err(2188):     at markitcommunity.org.markit.activity.LoginActivity$3.onResponse(LoginActivity.java:123)
11-29 17:42:04.065: W/System.err(2188):     at markitcommunity.org.markit.activity.LoginActivity$3.onResponse(LoginActivity.java:114)
11-29 17:42:04.065: W/System.err(2188):     at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:60)
11-29 17:42:04.065: W/System.err(2188):     at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:30)
11-29 17:42:04.065: W/System.err(2188):     at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99)
11-29 17:42:04.065: W/System.err(2188):     at android.os.Handler.handleCallback(Handler.java:739)
11-29 17:42:04.065: W/System.err(2188):     at android.os.Handler.dispatchMessage(Handler.java:95)
11-29 17:42:04.065: W/System.err(2188):     at android.os.Looper.loop(Looper.java:148)
11-29 17:42:04.065: W/System.err(2188):     at android.app.ActivityThread.main(ActivityThread.java:5417)
11-29 17:42:04.065: W/System.err(2188):     at java.lang.reflect.Method.invoke(Native Method)
11-29 17:42:04.066: W/System.err(2188):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
11-29 17:42:04.066: W/System.err(2188):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
11-29 17:42:04.114: W/EGL_emulation(2188): eglSurfaceAttrib not implemented
11-29 17:42:04.114: W/OpenGLRenderer(2188): Failed to set EGL_SWAP_BEHAVIOR on surface 0xa2dc7a20, error=EGL_SUCCESS

DB_Functions.PHP代碼-

<?php

class DB_Functions {

    private $conn;

    // constructor
    function __construct() {
        require_once 'DB_Connect.php';
        // connecting to database
        $db = new Db_Connect();
        $this->conn = $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

        $stmt = $this->conn->prepare("INSERT INTO users(unique_id, name, email, encrypted_password, salt, created_at) VALUES(?, ?, ?, ?, ?, NOW())");
        $stmt->bind_param("sssss", $uuid, $name, $email, $encrypted_password, $salt);
        $result = $stmt->execute();
        $stmt->close();

        // check for successful store
        if ($result) {
            $stmt = $this->conn->prepare("SELECT * FROM users WHERE email = ?");
            $stmt->bind_param("s", $email);
            $stmt->execute();
            $user = $stmt->get_result()->fetch_assoc();
            $stmt->close();

            return $user;
        } else {
            return false;
        }
    }

    /**
     * Get user by email and password
     */
    public function getUserByEmailAndPassword($email, $password) {

        $stmt = $this->conn->prepare("SELECT * FROM users WHERE email = ?");

        $stmt->bind_param("s", $email);

        if ($stmt->execute()) {
            $user = $stmt->get_result()->fetch_assoc();
            $stmt->close();
            return $user;
        } else {
            return NULL;
        }
    }

    /**
     * Check user is existed or not
     */
    public function isUserExisted($email) {
        $stmt = $this->conn->prepare("SELECT email from users WHERE email = ?");

        $stmt->bind_param("s", $email);

        $stmt->execute();

        $stmt->store_result();

        if ($stmt->num_rows > 0) {
            // user existed 
            $stmt->close();
            return true;
        } else {
            // user not existed
            $stmt->close();
            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;
    }

}

?>

經過幾乎所有地方的長時間研究並更改了主機，我意識到此特定行是導致錯誤的原因：

$user = $stmt->get_result()->fetch_assoc();

因為它獲取表的HTML版本，而不是其內容輸入用戶。

有人對如何解決這個問題有任何想法嗎？

Answer 1

經過長時間的研究，我的網絡托管似乎不支持mysqlnd驅動程序，因此我將代碼更改為以下代碼，從而解決了該問題。

/**
 * Get user by email and password
 */
public function getUserByEmailAndPassword($email, $password) {

    $stmt = $this->conn->prepare("SELECT unique_id,name,email,created_at,updated_at, encrypted_password , salt FROM users WHERE email = ?");

    $stmt->bind_param("s", $email);

    if ($stmt->execute()) {
            $stmt->store_result();
            $num_of_rows = $stmt->num_rows;
            $stmt->bind_result($aid, $aname, $aemail, $acreated_at, $aupdated_at , $aencrypted_password , $asalt);

                    while ($stmt->fetch()) {
                    $user[0] = $aid;
                    $user[1] = $aname;
                    $user[2] = $aemail;
                    $user[3] = $acreated_at;
                    $user[4] = $aupdated_at;
                    $user[5] = $aencrypted_password;
                    $user[6] = $asalt;
                    $user[7] = $this->checkhashSSHA($asalt, $password);
                    }
            $stmt->free_result();
            $stmt->close();
            return $user;
            } else {
            return NULL;
            }
    }

它幾乎一次從SQL 1列中收集數據，雖然沒有動態變化，但是可以工作。