Question

Android 4.2.2
我正在解析从PHP服务器发送的JSON字符串。解析相同的字符串每次都会在随机字符编号上出现此异常。有时它已成功加载。输入的大小为202858字节。我不能在这里发布，因为它是私人数据，但我想它的格式正确。如果我以调试/逐步模式运行我的应用程序，它会一直加载！此外，如果响应的大小较小（行数较少但不确定多少行），它也会一直加载。

以下是我加载流的方式：

        String JSONResp = "";

        try {
            URL u = new URL(params[1]);
            HttpURLConnection conn = (HttpURLConnection) u.openConnection();
            conn.setRequestMethod(params[0]);
            conn.connect();

            /* Here is the new code. This works! */
            BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"), 4096);
            StringBuilder  sb = new StringBuilder();

            String line = null;
            while( (line = br.readLine()) != null ) {
                sb.append(line + "\n");
            }
            JSONResp = sb.toString();


            /* Old code starts here. This is not working!
            // Read the stream
            InputStream is = conn.getInputStream();
            byte[] b = new byte[4096];
            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            while ( is.read(b) != -1) {
                baos.write(b);
            }

            JSONResp = new String(baos.toByteArray());
            */

            JSONArray arr = new JSONArray(JSONResp);

            //TODO read result form the input stream
            _HTTP_code = 200;

            return arr;
        }
        catch(Throwable t) {
            _HTTP_code = ERROR_Throwable;
            _HTTP_text = "Error";
            _HTTP_body = "Could not parse response!";

            Log.e("JSON", "JSONResp.length() = " + JSONResp.length() + ".");
            t.printStackTrace();
        }

代码是从一个单独的线程执行的，这是我在Android documentation中找到的：

此类的实例不是线程安全的。虽然这个类是非最终的，但它不是为继承而设计的，不应该是子类。特别是，未指定可覆盖方法的自用。有关详细信息，请参阅有效Java项目17，“设计和文档或继承或禁止它”。

我不确定我是否正确理解该文本，但我没有多个线程同时查询服务器。

任何帮助都将不胜感激。

Answer 1

public class GetResultTask extends AsyncTask<String, Void, String> {  
Activity act;
private ProgressDialog pd;
private boolean isInternetConnected = true;

public GetResultTask(Activity _act){
    this.act = _act;
    pd = ProgressDialog.show(act, null, "Loading...", true );
}

@Override
protected void onPreExecute() {

}

protected void onPostExecute(String result) {
    pd.dismiss();
    if(!isInternetConnected){
        //Toast.makeText(getApplicationContext(), "Check your Network Connection", Toast.LENGTH_LONG).show();
    }
}

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

    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("option", "getPeople"));
    nameValuePairs.add(new BasicNameValuePair("val", params[0]));

    String downloadedString = null;
    DefaultHttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost("http://example.com/filename.php");

    try {
        // Execute HTTP Post Request
        UrlEncodedFormEntity ent = new UrlEncodedFormEntity(nameValuePairs,HTTP.UTF_8);
        httppost.setEntity(ent);
        //new
        //HttpResponse response = httpClient.execute(httppost);
        //System.out.println("Response");
        HttpResponse response = httpclient.execute(httppost);
        //System.out.println("Response is :-\n"+response);

        InputStream in = response.getEntity().getContent();
        StringBuilder stringbuilder = new StringBuilder();
        BufferedReader bfrd = new BufferedReader(new InputStreamReader(in));
        String line;
        while((line = bfrd.readLine()) != null)
            stringbuilder.append(line);
        //string returned as JSON
        downloadedString = stringbuilder.toString();
    } 
    catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch(UnknownHostException e){
        isInternetConnected = false;

    }
    catch (IOException e) {
        e.printStackTrace();
    }catch (Exception e){
        e.printStackTrace();
    }
    //System.out.println(downloadedString);
    return downloadedString;

}   
 }

Random org.json.JSONException：字符24367处的未终止数组

1 个答案: