如何通过php/android优化从mysql获取数据？

Question

介绍

我有一个应用程序,并希望强制用户更新它,如果新版本在谷歌游戏市场.使用以下代码可以正常工作,但不是很稳定.我是通过AsyncTask进行的,并从php文件中获取数据.但它让我觉得必须有一种更好的方式或方式使它更稳定.

题

如何为程序设置超时,例如由于用户的互联网连接非常低？

码

get_newest_apk.php

<?PHP

    /*  GET APK VERSION FROM ANDROID DEVICE
        Example: [PATH]/get_newest_apk.php?apkversion=6
    */
    if($_GET["apkversion"]){
        $apkversion= $_GET["apkversion"];

        //MYSQL LOGIN PARAMETERS
        $host = '*****';
        $user = '*****';
        $pass = '*****';
        $db =   '*****';

        $mysqli = new mysqli($host, $user, $pass, $db);

            $result = $mysqli->query("SELECT MAX(VERSION) FROM TBL_APK");
            $row = $result->fetch_row();
            $count = $row[0];

            if($count > $apkversion){
                //Newer APK is avaiable
                echo "1";
            }else{
                //There is no never APK avaiable
                echo "2";
            }

    }else{
        //Error by GETTING apkversion from Android device
        echo "3";
    }
?>

AsyncTask类

class checkForNewAPK extends AsyncTask<Void, Void, String> {
    @Override
    protected void onPreExecute() {
        //Do not show the user a progress because he don't want to see it in every onResume
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
        int intResult = Integer.parseInt(s);

        //strResult as intResult; 1 = Newer APK avaiable, 2 = No newer APK avaiable, 3 = Error at $_GET["apkversion"] line 6
        if(intResult == 1){
            //Force to Update App
            Log.v("APKResult: ", "1");
        }else if(intResult == 2){
            //No update needed
            Log.v("APKResult: ", "2");
        }else if(intResult == 3){
            //Error in PHP-File
            Log.v("APKResult: ", "3");
        }else{
            //Unknown error
            Log.v("APKResult: ", "Unkown Error");
        }
    }

    //in this method we are fetching the json string
    @Override
    protected String doInBackground(Void... voids) {
        try {
            int intApkVersion = getApplication().getPackageManager().getPackageInfo(getPackageName(), 0).versionCode;
            URL url = new URL(strUrlGetNewestAPK+"?apkversion="+intApkVersion);
            String strResultFromEcho;

            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            StringBuilder strResult = new StringBuilder();

            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));
            while ((strResultFromEcho = bufferedReader.readLine()) != null) {
                strResult.append(strResultFromEcho + "\n");
            }

            return strResult.toString().trim();
        } catch (Exception e) {
            return null;
        }
    }
}

Answer 1

如何为程序设置超时,例如由于用户的互联网连接非常低？

你需要使用setConnectTimeout和setReadTimeout

setConnectTimeout

• 设置在打开与此URLConnection引用的资源的通信链接时要使用的指定超时值(以毫秒为单位).如果超时在可以建立连接之前到期,则引发java.net.SocketTimeoutException.超时为零被解释为无限超时.

setReadTimeout

• 将读取超时设置为指定的超时(以毫秒为单位).非零值指定在与资源建立连接时从输入流读取时的超时.如果在有可用于读取的数据之前超时到期,java.net.SocketTimeoutException则引发a.超时为零被解释为无限超时.

示例代码

   HttpURLConnection con = (HttpURLConnection) url.openConnection();
   con.setConnectTimeout(3000); //set connection time out in milliseconds
   con.setReadTimeout(3000); // set read time out in milliseconds

在代码中进行以下更改

class checkForNewAPK extends AsyncTask<Void, Void, String> {
    @Override
    protected void onPreExecute() {
        //Do not show the user a progress because he don't want to see it in every onResume
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
        int intResult = Integer.parseInt(s);

        //strResult as intResult; 1 = Newer APK avaiable, 2 = No newer APK avaiable, 3 = Error at $_GET["apkversion"] line 6
        if(intResult == 1){
            //Force to Update App
            Log.v("APKResult: ", "1");
        }else if(intResult == 2){
            //No update needed
            Log.v("APKResult: ", "2");
        }else if(intResult == 3){
            //Error in PHP-File
            Log.v("APKResult: ", "3");
        }else{
            //Unknown error
            Log.v("APKResult: ", "Unkown Error");
        }
    }

    //in this method we are fetching the json string
    @Override
    protected String doInBackground(Void... voids) {
        try {
            int intApkVersion = getApplication().getPackageManager().getPackageInfo(getPackageName(), 0).versionCode;
            URL url = new URL(strUrlGetNewestAPK+"?apkversion="+intApkVersion);
            String strResultFromEcho;

            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            con.setConnectTimeout(3000); //set connection time outt in milliseconds
            con.setReadTimeout(3000); // set read time outt in milliseconds

            StringBuilder strResult = new StringBuilder();

            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));
            while ((strResultFromEcho = bufferedReader.readLine()) != null) {
                strResult.append(strResultFromEcho + "\n");
            }

            return strResult.toString().trim();
        } catch (SocketTimeoutException e) {
            // this block code execute when time out exception is occur
            // you need to perform your logic here when time out exception occur
            return "Request timeout occur.\nTap on \'TRY AGAIN\' to retry";
        }
    }
}

注意:您还可以使用库进行API调用

你可以使用Volley图书馆

• Volley是一个HTTP库,它使Android应用程序的网络更容易,最重要的是,更快.Volley可在GitHub上找到.

来自DOCS

Volley提供以下好处:

• 自动调度网络请求.

• 多个并发网络连接.

• 具有标准HTTP缓存一致性的透明磁盘和内存响应缓存.支持请求优先级.

• 取消请求API.您可以取消单个请求,也可以设置要取消的请求块或范围.

• 易于定制,例如,重试和退避.

• 强大的排序功能,可以使用从网络异步获取的数据轻松正确填充UI.

• 调试和跟踪工具.

你可以使用Retrofit图书馆

• Square,Inc.为Android和Java提供类型安全的HTTP客户端. 改进Github链接

改造vs Volley

请阅读此文章Android网络库的比较:OkHTTP,Retrofit和Volley