Android应用程序可以直接连接到在线mysql数据库吗

是的，你可以这么做。

您需要的材料：

1. 网络服务器
2. Web服务器中存储的数据库
3. 还有一点Android知识:)
4. Webservices（json，Xml … etc）随便您如何使用

1. 首先在清单文件中设置Internet权限

 <uses-permission android:name="android.permission.INTERNET" />

2.创建 一个类以从服务器发出HTTPRequest（我正在使用json parisng获取值）

例如：

    public class JSonfunctions {    public static JSonObject getJSonfromURL(String url) {        InputStream is = null;        String result = "";        JSonObject jArray = null;        // Download JSON data from URL        try { HttpClient httpclient = new DefaultHttpClient(); HttpPost httppost = new HttpPost(url); HttpResponse response = httpclient.execute(httppost); HttpEntity entity = response.getEntity(); is = entity.getContent();        } catch (Exception e) { Log.e("log_tag", "Error in http connection " + e.toString());        }        // Convert response to string        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(); result = sb.toString();        } catch (Exception e) { Log.e("log_tag", "Error converting result " + e.toString());        }        try { jArray = new JSonObject(result);        } catch (JSonException e) { Log.e("log_tag", "Error parsing data " + e.toString());        }        return jArray;    }}

3. 在

MainActivity

JsonFunctions

例如：

JSonObject jsonobject;

jsonobject = JSONfunctions.getJSonfromURL("http://YOUR_DATAbase_URL");

4. 然后，最后读取jsontags并将值存储在arraylist中，如果需要，稍后在listview中显示它

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由于上述答案我写了很长回来，现在

HttpClient

HttpPost

HttpEntity

org.apache.http

android {    useLibrary 'org.apache.http.legacy'    signingConfigs {}    buildTypes {}}

或者您可以使用

HttpURLConnection

public String getJSON(String url, int timeout) {HttpURLConnection c = null;try {    URL u = new URL(url);    c = (HttpURLConnection) u.openConnection();    c.setRequestMethod("GET");    c.setRequestProperty("Content-length", "0");    c.setUseCaches(false);    c.setAllowUserInteraction(false);    c.setConnectTimeout(timeout);    c.setReadTimeout(timeout);    c.connect();    int status = c.getResponseCode();    switch (status) {        case 200:        case 201: BufferedReader br = new BufferedReader(new InputStreamReader(c.getInputStream())); StringBuilder sb = new StringBuilder(); String line; while ((line = br.readLine()) != null) {     sb.append(line+"n"); } br.close(); return sb.toString();    }} catch (MalformedURLException ex) {    Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);} catch (IOException ex) {    Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);} finally {   if (c != null) {      try {          c.disconnect();      } catch (Exception ex) {         Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);      }   }}return null;

}

或您可以使用第三方库（如

Volley

Retrofit

FasterXML-jackson

google-gson