我最近开始研究android,现在我正在使用AsyncTask如何获得从下面的API返回的响应是代码。每个建议都很明显。
class signmeup extends AsyncTask<String, String, String> {
private ProgressDialog pDialog;
JSONParser jsonParser = new JSONParser();
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(WolfActivity.this);
pDialog.setMessage("Loading");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected String doInBackground(String... arg0) {
// TODO Auto-generated method stub
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("section","user"));
params.add(new BasicNameValuePair("action","new"));
params.add(new BasicNameValuePair("device_type","2"));
params.add(new BasicNameValuePair("device_token","dhdkhgkdfhgkhfdghkdfjhgkjdfhgkdfhkhkHKhdkhsdkhKJHKWJHDSKAHDKJSAHJKDfhkashfkdjhfkjhskjhKJHJk"));
params.add(new BasicNameValuePair("first_name",fname));
params.add(new BasicNameValuePair("last_name",lname));
params.add(new BasicNameValuePair("email",email));
params.add(new BasicNameValuePair("phone",phone));
params.add(new BasicNameValuePair("fax",fax));
params.add(new BasicNameValuePair("address",addr));
params.add(new BasicNameValuePair("address1",addr1));
params.add(new BasicNameValuePair("facility",facility));
params.add(new BasicNameValuePair("password",pwd));
params.add(new BasicNameValuePair("zip",zipcode));
params.add(new BasicNameValuePair("city",city));
params.add(new BasicNameValuePair("state",state));
params.add(new BasicNameValuePair("how_you_found",huf));
params.add(new BasicNameValuePair("how_you_found_value",hufv));
// getting JSON Object
// Note that create product url accepts POST method
JSONObject json = jsonParser.makeHttpRequest("http://eastendwebsolutions.com/wf/ws/", "GET", params);
Log.d("First Name",fname);
Log.d("Last Name",lname);
Log.d("Email",email);
// check log cat for response
Log.d("Create Response", json.toString());
// check for success tag
try {
String success = json.getString("status");
String message = json.getString("message");
if(success == "0") {
Toast.makeText(WolfActivity.this,message ,Toast.LENGTH_LONG).show();
} else {
Toast.makeText(WolfActivity.this,"Error "+message ,Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
@SuppressWarnings("deprecation")
//@Override
protected void onPostExecute(String Result) {
if(pDialog.isShowing()){
pDialog.dismiss();
}
Log.d("Result",Result);
AlertDialog.Builder builder=new AlertDialog.Builder(WolfActivity.this);
builder.setTitle("Info");
builder.setMessage("Successfully registered");
builder.setIcon(R.drawable.app_icon);
builder.create().show();
}
}
以上代码以错误终止
java.lang.NullPointerException:尝试调用虚方法&#39; java.lang.String java.lang.String.toString()&#39;在null对象引用上 在zonup.wolf.WolfActivity $ signmeup.onPostExecute(WolfActivity.java:222) 在zonup.wolf.WolfActivity $ signmeup.onPostExecute(WolfActivity.java:135)
错误,因为此语句为Log.d(&#34; Result&#34;,Result);在功能上 onPostExecute(String Result)
我试图用doInBackground()方法提醒用户状态,但没有吐司即将来临:(它是否正确?
答案 0 :(得分:2)
试试这种方式,你可以看到你在json响应中得到的消息。
class signmeup extends AsyncTask<String, String, String> {
String message="";
private ProgressDialog pDialog;
JSONParser jsonParser = new JSONParser();
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(WolfActivity.this);
pDialog.setMessage("Loading");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected String doInBackground(String... arg0) {
// TODO Auto-generated method stub
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("section","user"));
params.add(new BasicNameValuePair("action","new"));
params.add(new BasicNameValuePair("device_type","2"));
params.add(new BasicNameValuePair("device_token","dhdkhgkdfhgkhfdghkdfjhgkjdfhgkdfhkhkHKhdkhsdkhKJHKWJHDSKAHDKJSAHJKDfhkashfkdjhfkjhskjhKJHJk"));
params.add(new BasicNameValuePair("first_name",fname));
params.add(new BasicNameValuePair("last_name",lname));
params.add(new BasicNameValuePair("email",email));
params.add(new BasicNameValuePair("phone",phone));
params.add(new BasicNameValuePair("fax",fax));
params.add(new BasicNameValuePair("address",addr));
params.add(new BasicNameValuePair("address1",addr1));
params.add(new BasicNameValuePair("facility",facility));
params.add(new BasicNameValuePair("password",pwd));
params.add(new BasicNameValuePair("zip",zipcode));
params.add(new BasicNameValuePair("city",city));
params.add(new BasicNameValuePair("state",state));
params.add(new BasicNameValuePair("how_you_found",huf));
params.add(new BasicNameValuePair("how_you_found_value",hufv));
// getting JSON Object
// Note that create product url accepts POST method
JSONObject json = jsonParser.makeHttpRequest("http://eastendwebsolutions.com/wf/ws/", "GET", params);
Log.d("First Name",fname);
Log.d("Last Name",lname);
Log.d("Email",email);
// check log cat for response
Log.d("Create Response", json.toString());
// check for success tag
try {
String success = json.getString("status");
message = json.getString("message");
if(success == "0") {
Toast.makeText(WolfActivity.this,message ,Toast.LENGTH_LONG).show();
} else {
Toast.makeText(WolfActivity.this,"Error "+message ,Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
message=e.toString();
e.printStackTrace();
}
return message;
}
@SuppressWarnings("deprecation")
//@Override
protected void onPostExecute(String Result) {
if(pDialog.isShowing()){
pDialog.dismiss();
}
Log.d("Result",Result);
AlertDialog.Builder builder=new AlertDialog.Builder(WolfActivity.this);
builder.setTitle("Info");
builder.setMessage(Result);
builder.setIcon(R.drawable.app_icon);
builder.create().show();
}
}