使用android php json远程连接到mysql数据库？

Question

我正在尝试使用带有 HTTP 连接的 android 应用程序连接到 mysql 数据库，然后检索 JSONArray 以扫描查询结果。代码如下：

public class MyActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);

        new JSONfunction().execute();
    }

    private class JSONfunction extends AsyncTask<Void,Void,JSONArray> {

        private JSONArray getJSONfromURL(String url) {
            InputStream is = null;
            String result = "";
            JSONArray 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();
                jArray=new JSONArray(result);
            } catch (Exception e) {
                Log.e("log_tag", "Error converting result " + e.toString());
            }


            return jArray;
        }



        @Override
        protected JSONArray doInBackground(Void... voids) {
            JSONArray jArray=getJSONfromURL("http://192.168.1.5/ConnectData/index.php");
            return jArray;
        }

        protected void onPostExecute(JSONArray result) {
            TextView prova = (TextView)findViewById(R.id.txtProva);
            try {

                JSONObject rec = result.getJSONObject(1);
                prova.setText(rec.getString("first_name"));

            }
            catch(JSONException e){
                Log.e("log_tag", "Error parsing data " + e.toString());
            }
        }
    }

我在执行 while 时遇到错误。在应用程序崩溃的 2 或 3 个周期之后。你能给我任何帮助吗？

[编辑]

我收到此错误： 11-28 20:42:19.006 27688-27702/com.example.marco.provadatabase E/log_tag﹕错误转换结果 org.json.JSONException: Value !DOCTYPE of type java.lang.String cannot be convert to JSONArray

[编辑 2]

好的，我明白了这个问题。但是现在我面临着一个新的。今天再次尝试执行代码，但现在我在 HttpResponse response = httpclient.execute(httppost); （昨天它工作得很好，我没有改变任何东西）。这不是 URL 问题，因为如果我把它放在浏览器上它就可以正常工作。

Answer 1

您的响应类型是字符串，您应该将其转换为 JSONObject

Answer 2

问题来了

result = sb.toString();
            jArray=new JSONArray(result);

您正在尝试获取响应字符串的 jsonarray，我相信它的根目录没有 jsonarray。您能否分享您的请求的回复。

针对您的超时问题

在我的示例中设置了两个超时。连接超时抛出“java.net.SocketTimeoutException: Socket is not connected”和socket timeout“java.net.SocketTimeoutException: The operation timed out”。

HttpGet httpGet = new HttpGet(url);
HttpParams httpParameters = new BasicHttpParams();
// Set the timeout in milliseconds until a connection is established.
// The default value is zero, that means the timeout is not used. 
int timeoutConnection = 3000;
HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
// Set the default socket timeout (SO_TIMEOUT) 
// in milliseconds which is the timeout for waiting for data.
int timeoutSocket = 5000;
HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);

DefaultHttpClient httpClient = new DefaultHttpClient(httpParameters);
HttpResponse response = httpClient.execute(httpGet);

如果您想设置任何现有 HTTPClient 的参数（例如 DefaultHttpClient 或 AndroidHttpClient），您可以使用函数 setParams()。

httpClient.setParams(httpParameters);

Hop 它为您解决问题:)