Question

我想从mysql表中获取数据，我使用doInBackground但是犯了错误

这是我的代码：

    private class getStatistics extends AsyncTask<String, String, String> {

        private InputStream is = null;
        private String url = "http://xxx/get_statistics.php";
        private String page_output = "";


        @Override
        protected String doInBackground(String... args) {

            Log.i("shis app ControlPanel", "Start get all Statistics ");

            try {
                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(url);

                HttpResponse httpResponse = httpClient.execute(httpPost);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                Log.i("shis app ControlPanel", "3");
                BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"), 8);
                StringBuilder sb = new StringBuilder();

                String line = null;
                while ((line = reader.readLine()) != null)
                {
                    sb.append(line + "\n");
                }
                is.close();
                page_output = sb.toString();
            } catch (Exception e) {
                Log.e("Buffer Error", "Error converting result " + e.toString());
            }

            return page_output;
        }

        @Override
        protected void onPostExecute(String page_output) {
                //pDialog.dismiss();
            try {

                statJSON=page_output;

                if(Integer.parseInt(page_output.trim())>=0){
                    statAll=Integer.parseInt(statJSON.trim());
                }

            } catch (Exception e) {
                e.printStackTrace();
            }
       }
   }

这是错误：

12-19 04:50:37.513: E/AndroidRuntime(992): FATAL EXCEPTION: AsyncTask #1
12-19 04:50:37.513: E/AndroidRuntime(992): java.lang.RuntimeException: An error occured while executing doInBackground()
12-19 04:50:37.513: E/AndroidRuntime(992):  at android.os.AsyncTask$3.done(AsyncTask.java:299)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.util.concurrent.FutureTask.run(FutureTask.java:239)
12-19 04:50:37.513: E/AndroidRuntime(992):  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.lang.Thread.run(Thread.java:841)
12-19 04:50:37.513: E/AndroidRuntime(992): Caused by: java.lang.SecurityException: Permission denied (missing INTERNET permission?)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.net.InetAddress.lookupHostByName(InetAddress.java:418)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.net.InetAddress.getAllByName(InetAddress.java:214)
12-19 04:50:37.513: E/AndroidRuntime(992):  at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
12-19 04:50:37.513: E/AndroidRuntime(992):  at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
12-19 04:50:37.513: E/AndroidRuntime(992):  at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
12-19 04:50:37.513: E/AndroidRuntime(992):  at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
12-19 04:50:37.513: E/AndroidRuntime(992):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
12-19 04:50:37.513: E/AndroidRuntime(992):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
12-19 04:50:37.513: E/AndroidRuntime(992):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
12-19 04:50:37.513: E/AndroidRuntime(992):  at com.example.shispanel.SplashActivity$getStatistics.doInBackground(SplashActivity.java:67)
12-19 04:50:37.513: E/AndroidRuntime(992):  at com.example.shispanel.SplashActivity$getStatistics.doInBackground(SplashActivity.java:1)
12-19 04:50:37.513: E/AndroidRuntime(992):  at android.os.AsyncTask$2.call(AsyncTask.java:287)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.util.concurrent.FutureTask.run(FutureTask.java:234)
12-19 04:50:37.513: E/AndroidRuntime(992):  ... 4 more
12-19 04:50:37.513: E/AndroidRuntime(992): Caused by: libcore.io.GaiException: getaddrinfo failed: EAI_NODATA (No address associated with hostname)
12-19 04:50:37.513: E/AndroidRuntime(992):  at libcore.io.Posix.getaddrinfo(Native Method)
12-19 04:50:37.513: E/AndroidRuntime(992):  at libcore.io.ForwardingOs.getaddrinfo(ForwardingOs.java:61)
12-19 04:50:37.513: E/AndroidRuntime(992):  at java.net.InetAddress.lookupHostByName(InetAddress.java:405)
12-19 04:50:37.513: E/AndroidRuntime(992):  ... 17 more
12-19 04:50:37.513: E/AndroidRuntime(992): Caused by: libcore.io.ErrnoException: getaddrinfo failed: EACCES (Permission denied)
12-19 04:50:37.513: E/AndroidRuntime(992):  ... 20 more

Answer 1

请注意错误消息：

引起：java.lang.SecurityException：权限被拒绝（缺失 INTERNET许可？）

您错过了权限：

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

在打开<application>标记之前将其添加到清单文件中。

Answer 2

请在Manifest中添加权限。

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

Android：从mysql获取数据时doInBackground出错

2 个答案: