我正在从URL解析数据。我正在使用下面的代码在logcat中获取明文数据。但是，尽管没有问题，但显示为空。
class RetrieveFeedTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... arg0) {
int responseCode = -1;
//String responseData;
try {
URL retailerUrl = new URL("http://clients.appatlantis.com/soldy/wp-json/wp/v2/soldy-clients");
HttpURLConnection connection = (HttpURLConnection) retailerUrl.openConnection();
connection.connect();
responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
InputStream inputStream = connection.getInputStream();
Reader reader = new InputStreamReader(inputStream);
int contentLength = connection.getContentLength();
char[] charArray = new char[contentLength];
reader.read(charArray);
String responseData = new String(charArray);
data = responseData;
Log.v(TAG, "Parse Data "+data);
} else {
Log.e(TAG, "Parse Data Failed");
}
} catch (MalformedURLException e) {
Log.e(TAG, "URL Exeption: ", e);
} catch (IOException e) {
Log.e(TAG, "IO URL Exeption: ", e);
} catch (Exception e) {
Log.e(TAG, "Exeption Caught: ", e);
}
return "Response Code "+data;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
Log.v(TAG, "Parse Data "+data);
}
}
这是完整的回溯。请注意，错误以
NegetiveArraySizeException形式抛出，因为没有结果。2020-04-12 02:41:03.853 7262-7373/com.appatlantis.jsonsample D/NetworkSecurityConfig: No Network Security Config specified, using platform default
2020-04-12 02:41:03.867 7262-7373/com.appatlantis.jsonsample W/System: ClassLoader referenced unknown path: system/framework/mediatek-cta.jar
2020-04-12 02:41:03.870 7262-7373/com.appatlantis.jsonsample I/System.out: e:java.lang.ClassNotFoundException: com.mediatek.cta.CtaHttp
2020-04-12 02:41:03.881 7262-7373/com.appatlantis.jsonsample W/System: ClassLoader referenced unknown path: system/framework/mediatek-cta.jar
2020-04-12 02:41:03.884 7262-7373/com.appatlantis.jsonsample I/System.out: e:java.lang.ClassNotFoundException: com.mediatek.cta.CtaHttp
2020-04-12 02:41:03.945 7262-7373/com.appatlantis.jsonsample I/System.out: [OkHttp] sendRequest>>
2020-04-12 02:41:03.947 7262-7373/com.appatlantis.jsonsample I/System.out: [OkHttp] sendRequest<<
2020-04-12 02:41:04.402 7262-7373/com.appatlantis.jsonsample E/MainActivity: Exeption Caught:
java.lang.NegativeArraySizeException: -1
at com.appatlantis.jsonsample.MainActivity$RetrieveFeedTask.doInBackground(MainActivity.java:85)
at com.appatlantis.jsonsample.MainActivity$RetrieveFeedTask.doInBackground(MainActivity.java:58)
at android.os.AsyncTask$2.call(AsyncTask.java:333)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:764)
2020-04-12 02:41:04.402 7262-7262/com.appatlantis.jsonsample V/MainActivity: Parse Data null
最佳答案
这是因为connection.getContentLength()返回-1。发生这种情况是因为内容长度未知。更具体地说，服务器未在响应消息中设置“ Content-Length”标头。
您可以做的是
InputStream inputStream = connection.getInputStream();
Scanner s = new Scanner(inputStream).useDelimiter("\\A");
data = s.hasNext() ? s.next() : "";
Log.v(TAG, "Parse Data " + data);
这将起作用。
关于java - Android-从URL解析JSON明文返回空值，但可以连接，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/61163620/