Question

我尝试使用带有HTTP连接的Android应用程序连接到mysql数据库，然后重新启动JSONArray以扫描查询结果。这是代码：

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。在应用程序崩溃之后的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：转换结果时出错org.json.JSONException：值！java.lang.String类型的DOCTYPE无法转换为JSONArray

[编辑2]

好的我明白了这个问题。现在，我正面对一个新的。今天再次尝试执行代码，但现在我在线路上得到一个超时异常HttpResponse response = httpclient.execute（httppost）; （昨天工作正常，我没有改变任何事情）。它不是一个URL问题，因为如果我将它放在浏览器上它可以正常工作。

Answer 1

您的响应类型是String，您应该将其转换为JSONObject

Answer 2

这是问题

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

你正在尝试获取你的响应字符串的jsonarray，我认为它的根目录没有jsonarray。您能否根据您的要求分享回复。

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未连接”和套接字超时“java.net.SocketTimeoutException：操作超时”。

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);

如果要设置任何现有HTTPClient的参数（例如DefaultHttpClient或AndroidHttpClient），可以使用函数setParams（）。

httpClient.setParams(httpParameters);

为你清楚地说明事情：）

使用android php json远程连接到mysql数据库？

2 个答案: