在Java Android App中將輸入流轉換為字符串值

Question

我正在編寫函數時遇到問題。 我正在嘗試將輸入流轉換為字符串值。 我寫了兩個函數，我試圖提取String值，但我的Log.e響應返回NULL。 以下是我的語法。 我究竟做錯了什么？ 謝謝

public JSONArray GetCityDetails(String StateID) {

    @SuppressWarnings("deprecation")
    String url = "http://mywebsite.com/getCity.php?StateID="+URLEncoder.encode(StateID);

    HttpEntity httpEntity = null;

    try{

         DefaultHttpClient httpClient = new DefaultHttpClient();
         HttpGet httpGet = new HttpGet(url);

         HttpResponse httpResponse = httpClient.execute(httpGet);

         httpEntity = httpResponse.getEntity();


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

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


    JSONArray jsonArray = null;
    if(httpEntity !=null){
        try{

            InputStream entityResponse = httpEntity.getContent();
            // not working
            String entityResponseAfterFunctionCall2 = readFully(entityResponse);
            // not working
            String entityResponseAfterFunctionCall3 = letsDoThisAgain(entityResponse);
            Log.e("Entity Response Dude: ", entityResponseAfterFunctionCall3);

            jsonArray = new JSONArray(entityResponseAfterFunctionCall3);

        } catch(JSONException e){
            e.printStackTrace();
        } catch(IOException e){
            e.printStackTrace();
        }
    }

    return jsonArray;
}

public String readFully(InputStream entityResponse) throws IOException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    byte[] buffer = new byte[1024];
    int length = 0;
    while ((length = entityResponse.read(buffer)) != -1) {
        baos.write(buffer, 0, length);
    }
    return baos.toString();
}

public String letsDoThisAgain(InputStream entityResponse){

    InputStreamReader is = new InputStreamReader(entityResponse);
    StringBuilder sb = new StringBuilder();
    BufferedReader br = new BufferedReader(is);
    try {
        String read = br.readLine();

        while(read !=null){
            sb.append(read);
            read = br.readLine();
        }

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

    return sb.toString();   
}

}

Answer 1

if(inputStream != null)
        {
            BufferedReader br = null;
            StringBuilder sb = new StringBuilder();

            String line;
            try {

                br = new BufferedReader(new InputStreamReader(inputStream));
                while ((line = br.readLine()) != null) {
                    sb.append(line);
                }

            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (br != null) {
                    try {
                        br.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }

            return sb.toString();
        }
        else
        {
            return "";
        }

Answer 2

readFully調用將使用系統的默認字符編碼將字節緩沖區轉換為String。 這不是你想要發生的事情。

您應該在toString調用中使用顯式字符集。 編碼通常在HTTP請求標頭中指定。

以下是如何轉換UTF-8編碼字符串的示例

return baos.toString( "UTF-8" );

你的第二個問題是，一旦你在readFully調用中消耗了InputString， letsDoThisAgain將沒有任何東西可以讀取，因為InputStream將處於EOF。