Question

我想从Android应用程序中的Web服务器检索数据，并且不知道从哪里开始。我应该使用网络服务吗？

Answer 1

我会推荐这些教程：

Connect android with PHP and MySql，JSON in android和PHP and MySQLi

我使用了这些教程，并设法在没有太多困难的情况下获得您正在尝试的工作。

在它们之间，它们描述了如何在每个阶段，Android应用程序，数据库和Web服务器端执行您所尝试的操作的每个步骤，并包含额外信息，以便您可以执行哪些操作来处理和使用收到的信息

我唯一要补充的是Connect PHP with PHP和MySql教程使用了不推荐使用的php中的mysql_。使用MySqli要好得多，这就是我加入第三个链接的原因。

您想要做的基本概要是：

1）在Android应用程序中使用类似这样的类向服务器php脚本发出请求：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;

import android.util.Log;

public class JSONParser {

    // Response from the HTTP Request
    static InputStream httpResponseStream = null;
    // JSON Response String to create JSON Object
    static String jsonString = "";

    // Method to issue HTTP request, parse JSON result and return JSON Object
    public JSONObject makeHttpRequest(String url, String method,
            List<NameValuePair> params) {

        try {
            // get a Http client
            DefaultHttpClient httpClient = new DefaultHttpClient();

            // If required HTTP method is POST
            if (method == "POST") {
                // Create a Http POST object
                HttpPost httpPost = new HttpPost(url);
                // Encode the passed parameters into the Http request
                httpPost.setEntity(new UrlEncodedFormEntity(params));
                // Execute the request and fetch Http response
                HttpResponse httpResponse = httpClient.execute(httpPost);
                // Extract the result from the response
                HttpEntity httpEntity = httpResponse.getEntity();
                // Open the result as an input stream for parsing
                httpResponseStream = httpEntity.getContent();
            }
            // Else if it is GET
            else if (method == "GET") {
                // Format the parameters correctly for HTTP transmission
                String paramString = URLEncodedUtils.format(params, "utf-8");
                // Add parameters to url in GET format
                url += "?" + paramString;
                // Execute the request
                HttpGet httpGet = new HttpGet(url);
                // Execute the request and fetch Http response
                HttpResponse httpResponse = httpClient.execute(httpGet);
                // Extract the result from the response
                HttpEntity httpEntity = httpResponse.getEntity();
                // Open the result as an input stream for parsing
                httpResponseStream = httpEntity.getContent();
            }
            // Catch Possible Exceptions
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            // Create buffered reader for the httpResponceStream
            BufferedReader httpResponseReader = new BufferedReader(
                    new InputStreamReader(httpResponseStream, "iso-8859-1"), 8);
            // String to hold current line from httpResponseReader
            String line = null;
            // Clear jsonString
            jsonString = "";
            // While there is still more response to read
            while ((line = httpResponseReader.readLine()) != null) {
                // Add line to jsonString
                jsonString += (line + "\n");
            }
            // Close Response Stream
            httpResponseStream.close();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        try {
            // Create jsonObject from the jsonString and return it
            return new JSONObject(jsonString);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
            // Return null if in error
            return null;
        }
    }
}

处理通信，打开连接并接收JSON字符串，然后将其处理为JSON对象。

2）在php服务器中，打开一个mysqli连接到你的SQL数据库，运行一个mysqli-＆gt; query（）并执行以下结果：

if (mysqli_num_rows($result) > 0) {
        // looping through all results
        $response["apps"] = array();

        while ($row = mysqli_fetch_array($result)) {

            $apps = array();

            $apps["name"] = $row["name"];
            $apps["package"] = $row["package"];
            $apps["version"] = $row["version"];
            $apps["dateversion"] = $row["dateversion"];
            $apps["sdkver"] = $row["sdkver"];
            $apps["pathroot"] = $row["pathroot"];
            $apps["rootname"] = $row["rootname"];
            $apps["apkmd5"] = $row["apkmd5"];
            $apps["extraapkmd5"] = $row["extraapkmd5"];
            $apps["instructionsmd5"] = $row["instructionsmd5"];
            $apps["assetsmd5"] = $row["assetsmd5"];
            $apps["root"] = $row["root"];
            $apps["current"] = $row["current"];

            // push single product into final response array
            array_push($response["apps"], $apps);
        }
        // success
        $response["success"] = 1;

        // echoing JSON response
        echo json_encode($response);

这会迭代数据库响应并将其编码为JSON字符串，然后发送回Android应用程序，然后可以处理它。

如何创建这样的内容在链接的教程中进行了解释

Answer 2

首先，您必须在要使用的网络服务之间进行选择然后找出最符合您需求的类型根据我的说法，解析json，xml或soap的最简单的方法是跟随（使用教程链接）：
     Json :Jackson frame work
     xml :Simple framework
     soap :ksoap2 framework

Answer 3

这不会直接回答您的问题，但由于您已经问过从哪里开始，您应该通过在AsyncTask中构建Web请求来正确启动。这将允许您在单独的线程中发出请求，并在UI上设置数据。

AsyncTasks使用线程池和工作队列也可以轻松更新用户的进度。这里有一些很好的例子：AsyncTask Android example

如何从Android应用程序中的Web服务器获取数据？

3 个答案: