我有2个同样错误的课程，你能告诉我它有什么问题吗，我使用了本地ip adrees。它是10.0.2.2 这是我的doInBackgroundclass
String url_param;
url_param = "http://10.0.2.2/webservice/android.php?pl=info";
JSONParser jParser = new JSONParser();
JSONObject json = jParser.getJSONFromUrl(url + url_param);
Log.d("log", "url:" + url + url_param);
try {
JSONArray result = json.getJSONArray("result");
for (int i = 0; i < result.length(); i++) {
JSONObject c = result.getJSONObject(i);
String id = c.getString("id");
String nama = c.getString("nama");
String info = c.getString("info");
String tanggal = c.getString("tanggal");
HashMap<String, String> map = new HashMap<String, String>();
map.put(in_id, id);
map.put(in_nama, nama);
map.put(in_info, info);
map.put(in_tanggal, tanggal);
resultList.add(map);
}
Log.d("log", "bla:" + resultList);
} catch (JSONException e) {
e.printStackTrace();
}
return null;
这是log cat，所以起初我认为它来自ip地址，但我不确定，我把这个服务器放在localhost上
FATAL EXCEPTION: AsyncTask #1
java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:309)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'org.json.JSONArray org.json.JSONObject.getJSONArray(java.lang.String)' on a null object reference