从数据库获取数据并将其显示在android应用程序上

Question

我已经在MySQL上设计了数据库，并通过php将其链接。 如何使用HTTP GET方法在android应用程序上获取它？ 我为此目的使用JSON解析来从MYSQL获取数据，但是我无法显示：（（（现在我想从HTTP GET请求获取数据，所以我该如何使用它？我将数据库上传到服务器上吗？如何我上传了它？它的处理方法是什么，我将感谢您的帮助

MySQL数据库是：

    <?php
// read_My_Task.php


/*
 * Following code will get single task details
 * A task_detail is identified by task id (cid)
 */
 // array for JSON response
$response = array();

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

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

// check for post data
if (isset($_GET["cid"])) {
    $cid = $_GET['cid'];

    // get a task from my-task table
    $result = mysql_query("SELECT *FROM my_task WHERE cid = $cid");

    if (!empty($result)) {
        // check for empty result
        if (mysql_num_rows($result) > 0) {

            $result = mysql_fetch_array($result);

            $my_task = array();
            $my_task["cid"] = $result["cid"];
            $my_task["cus_name"] = $result["cus_name"];
            $my_task["contact_number"] = $result["contact_number"];
            $my_task["ticket_no"] = $result["ticket_no"];
            $my_task["task_detail"] = $result["task_detail"];

            // user node
            $response["my_task"] = array();

            array_push($response["my_task"], $my_task);
            // echoing JSON response
            echo json_encode($response);         
             }            

        else {
            // no task found
            $response["success"] = 0;
            $response["message"] = "No task found";

            // echo no users JSON
            echo json_encode($response);
        }
    } else {
        // no task found
        $response["success"] = 0;
        $response["message"] = "No task found";

        // echo no users JSON
        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);
}

?>

LogCat错误是：

12-17 11:00:39.180: W/System.err(10667): org.apache.http.conn.ConnectTimeoutException: Connect to /198.168.0.29:80 timed out
12-17 11:00:39.180: W/System.err(10667):    at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:121)
12-17 11:00:39.180: W/System.err(10667):    at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:143)
12-17 11:00:39.180: W/System.err(10667):    at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
12-17 11:00:39.180: W/System.err(10667):    at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
12-17 11:00:39.180: W/System.err(10667):    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:359)
12-17 11:00:39.180: W/System.err(10667):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
12-17 11:00:39.180: W/System.err(10667):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
12-17 11:00:39.180: W/System.err(10667):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
12-17 11:00:39.180: W/System.err(10667):    at com.example.visit.record.JSONParser.makeHttpRequest(JSONParser.java:62)
12-17 11:00:39.180: W/System.err(10667):    at com.example.visit.record.My_Task$GetTaskDetails.doInBackground(My_Task.java:170)
12-17 11:00:39.180: W/System.err(10667):    at com.example.visit.record.My_Task$GetTaskDetails.doInBackground(My_Task.java:1)
12-17 11:00:39.180: W/System.err(10667):    at android.os.AsyncTask$2.call(AsyncTask.java:185)
12-17 11:00:39.180: W/System.err(10667):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
12-17 11:00:39.180: W/System.err(10667):    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
12-17 11:00:39.180: W/System.err(10667):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
12-17 11:00:39.180: W/System.err(10667):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
12-17 11:00:39.190: W/System.err(10667):    at java.lang.Thread.run(Thread.java:1027)
12-17 11:00:39.190: E/Buffer Error(10667): Error converting result java.lang.NullPointerException
12-17 11:00:39.190: E/JSON Parser(10667): Error parsing data org.json.JSONException: End of input at character 0 of 
12-17 11:00:39.190: W/dalvikvm(10667): threadid=9: thread exiting with uncaught exception (group=0x400205a0)
12-17 11:00:39.200: E/AndroidRuntime(10667): FATAL EXCEPTION: AsyncTask #1
12-17 11:00:39.200: E/AndroidRuntime(10667): java.lang.RuntimeException: An error occured while executing doInBackground()
12-17 11:00:39.200: E/AndroidRuntime(10667):    at android.os.AsyncTask$3.done(AsyncTask.java:200)
12-17 11:00:39.200: E/AndroidRuntime(10667):    at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
12-17 11:00:39.200: E/AndroidRuntime(10667):    at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
12-17 11:00:39.200: E/AndroidRuntime(10667):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
12-17 11:00:39.200: E/AndroidRuntime(10667):    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
12-17 11:00:39.200: E/AndroidRuntime(10667):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
12-17 11:00:39.200: E/AndroidRuntime(10667):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
12-17 11:00:39.200: E/AndroidRuntime(10667):    at java.lang.Thread.run(Thread.java:1027)
12-17 11:00:39.200: E/AndroidRuntime(10667): Caused by: java.lang.NullPointerException
12-17 11:00:39.200: E/AndroidRuntime(10667):    at com.example.visit.record.My_Task$GetTaskDetails.doInBackground(My_Task.java:174)
12-17 11:00:39.200: E/AndroidRuntime(10667):    at com.example.visit.record.My_Task$GetTaskDetails.doInBackground(My_Task.java:1)
12-17 11:00:39.200: E/AndroidRuntime(10667):    at android.os.AsyncTask$2.call(AsyncTask.java:185)
12-17 11:00:39.200: E/AndroidRuntime(10667):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
12-17 11:00:39.200: E/AndroidRuntime(10667):    ... 4 more
12-17 11:00:39.510: E/WindowManager(10667): Activity com.example.visit.record.My_Task has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4054caf0 that was originally added here
12-17 11:00:39.510: E/WindowManager(10667): android.view.WindowLeaked: Activity com.example.visit.record.My_Task has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4054caf0 that was originally added here
12-17 11:00:39.510: E/WindowManager(10667):     at android.view.ViewRoot.<init>(ViewRoot.java:277)
12-17 11:00:39.510: E/WindowManager(10667):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
12-17 11:00:39.510: E/WindowManager(10667):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
12-17 11:00:39.510: E/WindowManager(10667):     at android.view.Window$LocalWindowManager.addView(Window.java:433)
12-17 11:00:39.510: E/WindowManager(10667):     at android.app.Dialog.show(Dialog.java:288)
12-17 11:00:39.510: E/WindowManager(10667):     at com.example.visit.record.My_Task$GetTaskDetails.onPreExecute(My_Task.java:149)
12-17 11:00:39.510: E/WindowManager(10667):     at android.os.AsyncTask.execute(AsyncTask.java:391)
12-17 11:00:39.510: E/WindowManager(10667):     at com.example.visit.record.My_Task.onCreate(My_Task.java:108)
12-17 11:00:39.510: E/WindowManager(10667):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
12-17 11:00:39.510: E/WindowManager(10667):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1785)
12-17 11:00:39.510: E/WindowManager(10667):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1842)
12-17 11:00:39.510: E/WindowManager(10667):     at android.app.ActivityThread.access$1500(ActivityThread.java:132)
12-17 11:00:39.510: E/WindowManager(10667):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1038)
12-17 11:00:39.510: E/WindowManager(10667):     at android.os.Handler.dispatchMessage(Handler.java:99)
12-17 11:00:39.510: E/WindowManager(10667):     at android.os.Looper.loop(Looper.java:143)
12-17 11:00:39.510: E/WindowManager(10667):     at android.app.ActivityThread.main(ActivityThread.java:4268)
12-17 11:00:39.510: E/WindowManager(10667):     at java.lang.reflect.Method.invokeNative(Native Method)
12-17 11:00:39.510: E/WindowManager(10667):     at java.lang.reflect.Method.invoke(Method.java:507)
12-17 11:00:39.510: E/WindowManager(10667):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
12-17 11:00:39.510: E/WindowManager(10667):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
12-17 11:00:39.510: E/WindowManager(10667):     at 

它给出了错误：

Status Code: 404 Not Found
Accept-Ranges: bytes
Content-Language: en
Content-Type: text/html; charset=iso-8859-1
Date: Mon, 17 Dec 2012 06:40:56 GMT
Keep-Alive: timeout=5, max=100
Proxy-Connection: Keep-Alive
Server: Apache/2.2.17 (Win32) mod_ssl/2.2.17 OpenSSL/0.9.8o PHP/5.3.4 mod_perl/2.0.4 Perl/v5.10.1
Transfer-Encoding: chunked
Vary: accept-language,accept-charset


Method: POST
URL: http://192.168.0.29/mobile/read_mytask.php?cid=1
Body: 
cid=cid &
cus_name=c
& contact_no=n
& ticket_no=t
& taskdetail=td

Answer 1

我将向您概述Android中客户端-服务器数据检索的工作方式。 您可以从那里根据您的特定要求定制它，因为您的问题表明我的基础知识差距很大。

您必须创建REST API（通过使用PHP，Ruby，Python等语言编写服务器端代码），Android应用程序可以使用该API来从MySQL数据库获取数据。

还有其他选择也可以避免使用REST API。 看到：

如何从MySql服务器转到Android应用程序？

请参阅此处以获取有关REST的初学者教程：

http://net.tutsplus.com/tutorials/other/a-beginners-introduction-to-http-and-rest/

编写API之后。 您可以使用HTTP GET请求查询它们并解析结果。 如果您以JSON格式返回数据，则以下是有关如何解析数据的教程：

http://www.vogella.com/articles/AndroidJSON/article.html

现在，您可以使用本机android方法将已解析的数据存储在本地数据库中。 在这里查看数据库教程：

http://www.vogella.com/articles/AndroidSQLite/article.html

一旦这一切都结束了。 您可以在本地数据库上执行CRUD操作，以使用基于XML的Android UI读取/处理数据并将其显示给用户。

Answer 2

public class JsonHelper 
{
    static String response = null;
    String jsonRes = "";
    public JSONObject JObj=null;
    public final static int GET = 1;
    public final static int POST = 2;

//  public final static String fullUrl = "http://10.0.2.2/fluentcmsonline/";

public JsonHelper()
    {

    }

    public JSONObject MakeJsonCall(String Url,int method)
    {
        return this.MakeJsonCall(Url, method, null);
    }

    public JSONObject MakeJsonCall(String Url,int method, List<NameValuePair> params)
    {
        try
        {
            DefaultHttpClient HttpClient = new DefaultHttpClient();
            HttpEntity httpentity = null;
            HttpResponse httprespo = null;
            if(method==POST)
            {
                 HttpPost httppost = new HttpPost(fullUrl+Url);
                //HttpPost httppost = new HttpPost(Url);
                if(params != null)
                {
                    httppost.setEntity(new UrlEncodedFormEntity(params));
                }

                httprespo = HttpClient.execute(httppost);
            }
            else
            {
                if(params != null)
                {
                    String paramString = URLEncodedUtils.format(params, HTTP.UTF_8);

                    Url += "?"+paramString;     
                }

                 HttpGet httpget = new HttpGet(fullUrl+Url);
                //HttpGet httpget = new HttpGet(Url);

                httprespo = HttpClient.execute(httpget);
            }
            httpentity = httprespo.getEntity();

            if(httpentity != null)
            {
                InputStream is = httpentity.getContent();
                BufferedReader buffer = new BufferedReader(new InputStreamReader(is,"UTF-8"),8);

                StringBuilder Sb = new StringBuilder();
                String Line = null;

                while((Line = buffer.readLine())!=null)
                {
                    Sb.append(Line+"\n");
                }
                is.close();
                jsonRes = Sb.toString();

            }

        }
         catch (UnsupportedEncodingException e) {
                e.toString();
        } catch (ClientProtocolException e) {
            e.toString();
        } catch (IOException e) {
                e.toString();
        }

        try
        {
            JObj = new JSONObject(jsonRes);
            Log.e("Data", jsonRes);
        }
        catch(JSONException e)
        {
            e.printStackTrace();
        }

        return JObj;
    }

}