try-statement中忽略了Android-return

Question

null

@Override
protected InputStream doInBackground(String... arg0) {
    URL url = null;
    InputStream is = null;
    HttpURLConnection urlConn = null;
    int responseCode = 0;

    try {
        url = new URL(arg0[0]);
        urlConn = (HttpURLConnection) url.openConnection();
        urlConn.setReadTimeout(10000);
        urlConn.setConnectTimeout(15000);
        urlConn.setRequestMethod("GET");
        urlConn.connect();

        responseCode = urlConn.getResponseCode();
        Log.d("DataHandlerInternet:RESPONSE_CODE", "The response is: " + responseCode);

        is= urlConn.getInputStream(); //-->(1)<--
        return is;
    }
    catch ( MalformedURLException e ) { // new URL() went wrong!
        //TODO error message. URL is not correct!
        e.printStackTrace();
    }
    catch (SocketTimeoutException e) { // Timeout while connecting or holding connection to URL.
        //TODO error message. Timeout happened!
        e.printStackTrace();
    }
    catch ( IOException e ) { // openConnection() failed!
        //TODO error message. Couldn't connect to URL!
        e.printStackTrace();
    }
    catch( Exception e ) { // Any other Exception!
        e.printStackTrace();
    }
    finally {
        try { if(is != null) { is.close(); } } catch(Exception e) {e.printStackTrace();}
        try { if(urlConn != null) { urlConn.disconnect(); } } catch(Exception e) {e.printStackTrace();}
    }

    return null;
}

@Override
protected String doInBackground(String... arg0) {
    URL url = null;
    InputStream is = null;
    HttpURLConnection urlConn = null;
    int responseCode = 0;

    try {
        url = new URL(arg0[0]);
        urlConn = (HttpURLConnection) url.openConnection();
        urlConn.setReadTimeout(10000);
        urlConn.setConnectTimeout(15000);
        urlConn.setRequestMethod("GET");
        urlConn.connect();

        responseCode = urlConn.getResponseCode();
        Log.d("DataHandlerInternet:RESPONSE_CODE", "The response is: " + responseCode);

        is= urlConn.getInputStream();
        StringBuilder sb = new StringBuilder();
        BufferedReader br = new BufferedReader(new InputStreamReader(is));
        String line = null;
        while (  (line = br.readLine()) != null ) {
            sb.append(line);
        }
        return sb.toString();
    }
    catch ( MalformedURLException e ) { // new URL() went wrong!
        //TODO error message. URL is not correct!
        e.printStackTrace();
    }
    catch (SocketTimeoutException e) { // Timeout while connecting or holding connection to URL.
        //TODO error message. Timeout happened!
        e.printStackTrace();
    }
    catch ( IOException e ) { // openConnection() failed!
        //TODO error message. Couldn't connect to URL!
        e.printStackTrace();
    }
    catch( Exception e ) { // Any other Exception!
        e.printStackTrace();
    }
    finally {
        try { if(is != null) { is.close(); } } catch(Exception e) {e.printStackTrace();}
        try { if(urlConn != null) { urlConn.disconnect(); } } catch(Exception e) {e.printStackTrace();}
    }

    return null;
}

但是，在完成while循环之后，返回行；被完全忽略。我已经用调试器检查了字符串中的数据，它是正确的！没有错误，没有例外。

Answer 1

finally在这两种情况下都将运行，在正常返回期间也将运行，没有异常。在finally语句子句中调用。close。

所以您的代码总是返回关闭的流。也许这不是你想要的。

您的描述（“跳转到finally语句”）看起来仍然非常像urlconn.getInputStream()引发的异常。奇怪的是你没有观察到它。