如何从 Android 应用程序发送特定字符串并将该字符串发布到网站？

Question

我是 android 开发的新手，我正在尝试为一个让用户订购食物的类项目制作一个 android 应用程序。一旦他们点击结帐按钮，就会有一个包含用户订单信息的字符串值（即 - 鸡肉三明治、西红柿、生菜、蛋黄酱、特殊说明，总计：5.99 美元）传递给下一个活动。但是，我还希望将这些信息从应用程序发送到网站，以便查看网页的人可以看到订单信息。解决此问题的最佳方法是什么？

我想出了如何使用 MySQL 和 phpmyadmin 处理用户登录/注册，但我不确定是否为这个特定的字符串再次这样做是显示食品订单的最佳方式。我不打算专门为一个字符串创建数据库。相反，我只想在网页上发布该订单信息，以便“员工”可以查看订单信息并开始处理食品订单。

我从这篇文章中找到了一些信息：How to send a data to a web server from Android

根据我从该帖子中发现的内容，这是我迄今为止所尝试的： 订单列表活动：

@Override
public void onClick(View v) {
    Intent myIntent = null;
    switch (v.getId()) {
        case R.id.checkout:
            if (MainActivity.amountBalance - orderPrice < 0) {
                Toast.makeText(Orderlist.this, "Insufficient balance!", Toast.LENGTH_SHORT).show();
            } else {
                MainActivity.amountBalance = MainActivity.amountBalance - orderPrice;
                myIntent = new Intent(Orderlist.this, OrderPlaced.class);
                Toast.makeText(getApplicationContext(),"Your order was placed!",Toast.LENGTH_LONG).show();
                HttpClient httpclient = new DefaultHttpClient();
                HttpPost httppost = new HttpPost("http://mywebsitename.com/mypage.php");
                try {
                    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(4);

                    nameValuePairs.add(new BasicNameValuePair("orderinfo", "Chicken sandwich: tomatoes, onions, cheese.\nTotal: $5.99."));
                    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                    httpclient.execute(httppost);

                } catch (ClientProtocolException e) {
                    // TODO Auto-generated catch block
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                }
                startActivity(i);
            }
            break;
        case R.id.cancel:
            i = new Intent(Orderlist.this, MainActivity.class);
            Toast.makeText(Orderlist.this, "All items have been removed from cart.", Toast.LENGTH_LONG).show();
            startActivity(i);
            break;


    }
}

我的页面.php

<?php
$filename="datatest.html";
file_put_contents($filename,$_POST["orderinfo"]."<br />",FILE_APPEND);
$msg=file_get_contents($filename);
echo $msg; ?>

不幸的是，这会导致我的代码崩溃并且不会向 mypage.php 发布任何内容。我该如何解决这个问题？

错误： 致命异常：主要
进程：com.example.kusha.finalproject，PID：5291

android.os.NetworkOnMainThreadException
                                                                              at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1303)
                                                                              at java.net.Inet6AddressImpl.lookupHostByName(Inet6AddressImpl.java:86)
                                                                              at java.net.Inet6AddressImpl.lookupAllHostAddr(Inet6AddressImpl.java:74)
                                                                              at java.net.InetAddress.getAllByName(InetAddress.java:752)
                                                                              at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:142)
                                                                              at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:169)
                                                                              at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:124)
                                                                              at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:366)
                                                                              at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:560)
                                                                              at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:492)
                                                                              at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:470)
                                                                              at com.example.kusha.finalproject.Orderlist.onClick(Orderlist.java:192)
                                                                              at android.view.View.performClick(View.java:5637)
                                                                              at android.view.View$PerformClick.run(View.java:22429)
                                                                              at android.os.Handler.handleCallback(Handler.java:751)
                                                                              at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                              at android.os.Looper.loop(Looper.java:154)
                                                                              at android.app.ActivityThread.main(ActivityThread.java:6119)
                                                                              at java.lang.reflect.Method.invoke(Native Method)
                                                                              at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
                                                                              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

-- 错误似乎来自 Orderlist.java:192，这是这里的这段代码：

 nameValuePairs.add(new BasicNameValuePair("orderinfo", "Chicken sandwich: 
 tomatoes, onions, cheese.\nTotal: $5.99."));
 httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
 httpclient.execute(httppost); //ERROR FROM HERE

谢谢！

Answer 1

您应该阅读有关 Restful Web 服务的内容。 Android将带有Json（或XML）字符串数据（可选）的Http请求发送到服务器。服务器（.Net MVC，Spring MVC，PHP ...）接收该请求，使用业务逻辑处理它，更新数据库并返回一个Json字符串结果到 Android。登录成功后，服务器必须向移动设备发送一个令牌，android 存储此令牌以验证下一个请求。在您的情况下，您可以使用 Http Request POST，将 Json 数据从 android 发布到服务器。为了更灵活，您可以使用带有 Flexjson 或 Gson 库的 DTO 序列化数据。您想知道如何做到这一点，请参阅下面的代码

public static String httpPost(String domain, String root, String body,
        String token, String username)
{
    String urlString = "http://"+domain+"/"+root;

    Log.d("httpPost-url",
            " url:"+urlString+
            " ,token:"+token+
            " ,httpPost-body:"+ body+
            " ,username:"+username);

    StringBuffer response = new StringBuffer();
    try {
        URL url = new URL(urlString);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setDoOutput(true);
        conn.setDoInput(true);
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-Type", "application/json");
        if(token!=null)
        {
            conn.setRequestProperty("Authorization", "Basic " + token);
        }
        if(username!=null)
        {
            conn.setRequestProperty("Username", username);
        }
        OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
        writer.write(body);
        writer.flush();
        BufferedReader br = null;
        try
        {
            Log.d("HttpUtil", "Http code:" + conn.getResponseCode());

            br = new BufferedReader(new InputStreamReader((conn.getInputStream())));
        }
        catch (IOException e)
        {
            e.printStackTrace();
            br = new BufferedReader(new InputStreamReader((conn.getErrorStream())));
        }
        String inputLine;
        while ((inputLine = br.readLine()) != null)
        {
            response.append(inputLine);
        }
        System.out.println("result from server:"+response.toString());
        conn.disconnect();

    }
    catch (Exception e)
    {
        e.printStackTrace();
        return null;
    }
    return  response.toString();
}


public static String httpGet(String domain, String urlRoot, String token,
                             String username)
{
    String urlString = "http://"+domain+"/"+urlRoot;
    Log.d("httpGet-url:",
            " url:"+urlString+
            " ,token:"+token+
            " ,username:"+username);
    StringBuffer response = new StringBuffer();
    try {
        URL url = new URL(urlString);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");
        conn.setRequestProperty("Content-Type", "application/json");
        if(token!=null)
        {
            conn.setRequestProperty("Authorization", "Basic " + token);
        }
        if(username!=null)
        {
            conn.setRequestProperty("Username", username);
        }
        Log.d("HttpUtil","Http code:"+conn.getResponseCode());

        BufferedReader br=null;

        if(conn.getResponseCode()>=200&&conn.getResponseCode()<300) {
            br = new BufferedReader(new InputStreamReader((conn.getInputStream())));
        }
        else if(conn.getResponseCode()>=400)
        {
            br = new BufferedReader(new InputStreamReader((conn.getErrorStream())));
        }

        String inputLine;
        while ((inputLine = br.readLine()) != null) {
            response.append(inputLine);
        }

        System.out.println("result from server:"+response.toString());

        conn.disconnect();

    } catch (Exception e) {

        e.printStackTrace();
        return null;
    }
    return  response.toString();
}

享受编码！

编辑 1

android.os.NetworkOnMainThreadException

你应该使用

AsyncTask 或 Handler

private class LoginTask extends AsyncTask<String, Void, String> {

    private ProgressDialog progress;

    protected String doInBackground(String... params)
    {
        LoginActivity.this.runOnUiThread(new Runnable() {
            public void run() {
                progress = new ProgressDialog(LoginActivity.this);
                progress.setTitle(getResources().getString(R.string.app_name));
                progress.setMessage(getResources().getString(R.string.loading));
                progress.setProgressStyle(ProgressDialog.STYLE_SPINNER);
                progress.setCancelable(true);
                progress.show();
            }
        } );

        String result = HttpUtil.httpPost(
                params[0],params[1],
                params[2], params[3],
                params[4]);

        return result;
    }

    protected void onPostExecute(String param) {
        progress.dismiss();

        if(param==null)
        {
            return ;
        }
        Log.d("onPostExecute:",param);
        try
        {
            LoginDTO result = new JSONDeserializer<LoginDTO>()
                    .use("data", DataLoginDTO.class)
                    .use("data.rights.values", RightObjectDTO.class)
                    .deserialize(param, LoginDTO.class);
            if(result.getData()!=null)
            {
                Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                //intent.putExtra;
                Bundle bundle = new Bundle();
                //bundle.putParcelableArrayList("rights", result.getData().getRights());

                String rightString= new JSONSerializer().serialize(result.getData().getRights());

                intent.putExtras(bundle);
                String token = result.getData().getToken();
                SharedPreferences sharedPref = LoginActivity.this.getSharedPreferences(getResources()
                        .getString(R.string.preference_file_key),  Context.MODE_PRIVATE);
                SharedPreferences.Editor editor = sharedPref.edit();
                editor.putString("token", token);
                editor.putString("username", usernameEditText.getText().toString());
                editor.putLong("employeeId", result.getData().getEmployeeId());
                editor.putString("rights", rightString);
                editor.commit();

                if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
                    startActivity(intent, ActivityOptions.makeSceneTransitionAnimation(LoginActivity.this).toBundle());
                }
                else
                {
                    startActivity(intent);
                }

            }
            else
            {
                android.app.AlertDialog dialog = new android.app.AlertDialog.Builder(LoginActivity.this)
                        .setTitle(R.string.app_name)
                        .setMessage(R.string.incorrect_username_or_password)
                        .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int which)
                            {
                                dialog.dismiss();
                            }
                        })
                        .setIcon(android.R.drawable.ic_dialog_alert)
                        .show();
            }
        }
        catch (Exception e)
        {
            e.printStackTrace();
            AlertDialog dialog = new AlertDialog.Builder(LoginActivity.this)
                    .setTitle(R.string.error)
                    .setMessage(R.string.an_error_has_occurred)
                    .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                            dialog.dismiss();
                        }
                    })
                    .setIcon(android.R.drawable.ic_dialog_alert)
                    .show();

        }
    }
}