java - Android PHP 向 MySQL 发出请求

Question

我正在尝试使用 android 向我的服务器发送 http 请求。服务器上有 PHP 脚本，用于添加/删除/编辑 MySQL 数据库中的项目。我无法判断我是否正在连接到服务器或执行代码时发生了什么，我收到 Error parsing data org.json.JSONException: Value

我对 PHP 很陌生，一直在遵循本教程的指导方针“http://www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/”，但我很困难。

PHP添加饮料

<?php

/*
 * Following code will create a new product row
 * All product details are read from HTTP Post Request
 */

// array for JSON response
$response = array();

// check for required fields
if (isset($_POST['name']) && isset($_POST['price']) && isset($_POST['quantity'])) {

$name = $_POST['name'];
$price = $_POST['price'];
$quantity = $_POST['quantity'];

// include db connect class
require_once __DIR__ . '/db_connect.php';

// connecting to db
$db = new DB_CONNECT();

// mysql inserting a new row
$result = mysql_query("INSERT INTO drinks(name, price, quantity) VALUES('$name', '$price', '$quantity')");

// check if row inserted or not
if ($result) {
    // successfully inserted into database
    $response["success"] = 1;
    $response["message"] = "Product successfully created.";

    // echoing JSON response
    echo json_encode($response);
} else {
    // failed to insert row
    $response["success"] = 0;
    $response["message"] = "Oops! An error occurred.";

    // echoing JSON response
    echo json_encode($response);
}
} else {
// required field is missing
$response["success"] = 0;
$response["message"] = "Required field(s) is missing";

// echoing JSON response
echo json_encode($response);
}?>

新饮料 Activity :

public class NewDrinkActivity extends Activity {

// Progress Dialog
private ProgressDialog pDialog;

JSONParser jsonParser = new JSONParser();
EditText inputName;
EditText inputPrice;
EditText inputQuantity;

// url to create new Drink
private static String url_create_Drink =    "http://jjohnson.bugs3.com/android_connect/create_drink.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.add_drink);

    // Edit Text
    inputName = (EditText) findViewById(R.id.edtName);
    inputPrice = (EditText) findViewById(R.id.edtPrice);
    inputQuantity = (EditText) findViewById(R.id.edtQuantity);

    // Create button
    Button btnAddDrink = (Button) findViewById(R.id.btnAdd);

    // button click event
    btnAddDrink.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View view) {
            // creating new Drink in background thread
            new CreateNewDrink().execute();
        }
    });
}

/**
 * Background Async Task to Create new Drink
 * */
class CreateNewDrink extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(NewDrinkActivity.this);
        pDialog.setMessage("Creating Drink..");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    /**
     * Creating Drink
     * */
    protected String doInBackground(String... args) {
        String name = inputName.getText().toString();
        String price = inputPrice.getText().toString();
        String quantity = inputQuantity.getText().toString();

        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("name", name));
        params.add(new BasicNameValuePair("price", price));
        params.add(new BasicNameValuePair("quantity", quantity));

        // getting JSON Object
        // Note that create Drink url accepts POST method
        JSONObject json = jsonParser.makeHttpRequest(url_create_Drink,
                "POST", params);

        // check log cat fro response
        Log.d("Create Response", json.toString());

        // check for success tag
        try {
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                // successfully created Drink
                Intent i = new Intent(getApplicationContext(), StockActivity.class);
                startActivity(i);

                // closing this screen
                finish();
            } else {
                // failed to create Drink
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        // dismiss the dialog once done
        pDialog.dismiss();
    }

}
}

JSON 解析器:

public class JSONParser {

static InputStream is = null;
static JSONObject jObj = null;
static String json = "";

// constructor
public JSONParser() {

}

// function get json from url
// by making HTTP POST or GET method
public JSONObject makeHttpRequest(String url, String method,
        List<NameValuePair> params) {

    // Making HTTP request
    try {

        // check for request method
        if(method == "POST"){
            // request method is POST
            // 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();

        }else if(method == "GET"){
            // request method is GET
            DefaultHttpClient httpClient = new DefaultHttpClient();
            String paramString = URLEncodedUtils.format(params, "utf-8");
            url += "?" + paramString;
            HttpGet httpGet = new HttpGet(url);

            HttpResponse httpResponse = httpClient.execute(httpGet);
            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();
    } 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;

}
}

如果有帮助，我将使用 ServerFree.com 来托管我的文件。

Answer 1

这就是我认为正在发生的事情......

您发出请求，它被发送到服务器并进行处理(正如我所见，PHP 不会出错)，然后您会收到如下所示的响应:

{"success":0,"message":"Required field(s) is missing"}

实际上，您从网络服务器收到以下内容:

{"success":0,"message":"Required field(s) is missing"}<!-- www.serversfree.com Analytics Code -->
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<script type="text/javascript">

  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', 'UA-24425628-3']);
  _gaq.push(['_setDomainName', window.location.host]);
  _gaq.push(['_setAllowLinker', true]);
  _gaq.push(['_trackPageview']);

  (function() {
    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();

</script>
<!-- End Of Analytics Code -->

因此，尽管您从网站以可视文本形式获取有效的 JSON，但您使用的网络主机正在添加自己的 JavaScript 以便推送其免费服务。

因此，你的 android 中的这些行失败了:

// getting JSON Object
// Note that create Drink url accepts POST method
JSONObject json = jsonParser.makeHttpRequest(url_create_Drink,"POST", params);

所以在我看来你有三个选择。

1) 寻找一个不会对您的回复执行此操作的新虚拟主机。您可以尝试在本地计算机上设置 WAMP，这不是很困难。在您了解有关开发的更多信息之前，它对于您的测试来说会更加安全。例如，我们可以通过 SQL 注入(inject)攻击您的数据库。

2) 与该网站合作，看看是否有办法不发送该代码

3) 在 android 调用之前编写一些代码来过滤响应的该部分。您需要创建一个 BufferedReader 等才能接收来自网页的响应。