Android的：如何在休息Web服务使用AsyncTask的？ [英] android: How to use asyncTask in Rest Web service?
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问题描述
我创造的，我已经登录登出活动的Android应用程序，Multilistview活动将数据从其他网络服务来了。这里的问题是，调用从登录活动WebService时，我得到错误的networkonmainthreadexception然后我搜索了有关异常护目镜，有人在堆栈溢出说使用的AsyncTask在code为分离线程，我在code实现的AsyncTask但不工作。我完全混淆了如何使用AsyncTask的，我想在下面的code添加的AsyncTask。我公司提供code，而不AsyncTask的，我做到了。任何人可以帮助我如何调用WebService时，正是使用AsyncTask的。
以下是编辑文本的通话功能。
获取数据 UserFunctions userFun =新UserFunctions（）; 如果（（username.trim（）长度（）方式＆gt; 0）及与放大器;（userpsw.trim（）长度（）大于0））{ JSONObject的JSON = userFun.loginUser（用户名，userpsw）;
。
。
。
下面是功能类
公开的JSONObject loginUser（USEREMAIL字符串，字符串userPsw）{ 清单＆LT;＆的NameValuePair GT; PARAMS =新的ArrayList＆LT;＆的NameValuePair GT;（）;
params.add（新BasicNameValuePair（标签，login_tag））;
params.add（新BasicNameValuePair（电子邮件，USEREMAIL））;
params.add（新BasicNameValuePair（密码，userPsw））;
JSONObject的JSON = jsonParser.getJsondataFromUrl（PARAMS）;
//Log.d(\"tag，json.toString（））;
返回JSON;
}
下面是实际WebService类
公共无效getJsondataFromUrl（列表＆LT;＆的NameValuePair GT; PARAMS）{ {
DefaultHttpClient的HttpClient =新DefaultHttpClient（）;
HttpPost httpPost =新HttpPost（URL）;
httpPost.setEntity（新UrlEn codedFormEntity（PARAMS））; HTT presponse HTT preSP = httpClient.execute（httpPost）;
HttpEntity httpEntity = HTT presp.getEntity（）;
inStream中= httpEntity.getContent（）;
//Log.d(tag，inStream.toString（））;
}赶上（UnsupportedEncodingException五）{
e.printStackTrace（）;
}赶上（ClientProtocolException E）{
e.printStackTrace（）;
}赶上（IOException异常五）{
e.printStackTrace（）;
} 尝试{
的BufferedReader bufferReader =新的BufferedReader（新的InputStreamReader
（插播广告，ISO-8859-1），8）;
StringBuilder的strBuilder =新的StringBuilder（）;
串线= NULL;
而（（行= bufferReader.readLine（））！= NULL）{
strBuilder.append（线+的n）;
}
inStream.close（）;
JSON = strBuilder.toString（）;
//Log.d(\"JSON，JSON）;
}赶上（例外五）{
e.printStackTrace（）;
}
//尝试分析字符串到一个JSON对象
尝试{
jsonObj =新的JSONObject（JSON）;
}赶上（JSONException E）{
e.printStackTrace（）;
} 返回jsonObj; * /
}
在此先感谢
解决方案
@覆盖
公共无效的onCreate（捆绑savedInstanceState）{
super.onCreate（savedInstanceState）;
requestWindowFeature（Window.FEATURE_NO_TITLE）;
的setContentView（R.layout.login）;
上下文=这一点;
Log.v（TAG +的onCreate，在OnCreate称为）;
用户名=（的EditText）findViewById（R.id.editText_user）;
密码=（EditText上）findViewById（R.id.editText_psw）; btngo =（的ImageButton）findViewById（R.id.imageButton_go）;
btngo.setOnClickListener（本）;}
@覆盖
公共无效的onClick（视图v）{
Log.v（TAG +的onClick，叫的onClick）;
如果（V == btngo）
{
用户= username.getText（）的toString（）修剪（）。
PSW = password.getText（）的toString（）修剪（）。
对话框= ProgressDialog.show（背景下，，请稍候...，真的！）; 调用getResult结果=新调用getResult（）;
result.execute（）; }
}}
私有类调用getResult扩展的AsyncTask＆LT;弦乐，太虚，字符串＆GT; { @覆盖
保护字符串doInBackground（字符串的URL ...）{
Log.v（TAG +.doInBackground，doInBackground方法调用）;
字符串response1 = NULL; HttpClient的HttpClient的=新DefaultHttpClient（）;
HttpPost httppost =新HttpPost（URL）;
// Log.d（回应，工作）;
尝试{ 清单＆LT;＆的NameValuePair GT; namevaluepairs中=新的ArrayList＆LT;＆的NameValuePair GT;（）;
nameValuePairs.add（新BasicNameValuePair（web服务，1））;
nameValuePairs.add（新BasicNameValuePair（EMAIL_ID用户））;
nameValuePairs.add（新BasicNameValuePair（密码，PSW））; httppost.setEntity（新UrlEn codedFormEntity（namevaluepairs中））;
HTT presponse响应= httpclient.execute（httppost）;
InputStream为= response.getEntity（）的getContent（）。
WebHelper webHelper =新WebHelper（）;
response1 = webHelper.convertStreamToString（是）;
Log.v（TAG +。doInBackground，JSON的回应是：+ response1）; }赶上（ClientProtocolException E）{
// TODO自动生成catch块
e.printStackTrace（）;
}赶上（IOException异常五）{
// TODO自动生成catch块
e.printStackTrace（）;
}
返回response1;
} @覆盖
保护无效onPostExecute（字符串结果）{ Log.v（TAG +.onPostExecute，onPostExecute方法调用）;
dialog.dismiss（）;
Log.v（TAG +。onPostExecute，JSON的回应是：+结果）; / *意向意图=新意图（LoginActivity.this，ChoiceExamActivity.class）;
startActivity（意向）;
* / 如果（结果！= NULL）{ 尝试{
// JSONTokener tokener =新JSONTokener（结果）;
JSONObject的resultObjct =新的JSONObject（结果）;
字符串USER_ID = resultObjct.getString（USER_ID）; 如果（user_id.equalsIgnoreCase（0））
{
ExamUtil.showAlert（LoginActivity.this，错误的用户名或密码）;
}
其他
{
字符串名字= resultObjct.getString（将First_Name）;
Log.v（TAG +。onPostExecute，用户ID为：+ USER_ID）;
Log.v（TAG +。onPostExecute，名字是：+姓名）; 意向意图=新意图（LoginActivity.this，ChoiceExamActivity.class）;
startActivity（意向）; } }赶上（JSONException E）{
e.printStackTrace（）;
}
赶上（例外五）{
e.printStackTrace（）;
}
} 其他{ ExamUtil.showAlert（LoginActivity.this，我们在处理请求的一些问题，再试一次。）;
}
}
}
}
I am creating apps in android in that I have login logout activity, Multilistview activity which data coming from rest web service. here problem is that when calling webservice from login activity I get error the networkonmainthreadexception then i searched on goggle about that exception, somebody said on stack overflow use AsyncTask in your code for seperation thread and I implemented asynctask in my code but not working. i am totally confusing how to use asynctask and I want to add asynctask in following code. I provide code without asynctask which i did. can anybody to help me how to exactly use asynctask when calling webservice.
following is the get data from edit text call function
UserFunctions userFun = new UserFunctions();
if ((username.trim().length() > 0)&&(userpsw.trim().length() > 0)) {
JSONObject json = userFun.loginUser(username, userpsw);
.
.
.
following is the function class
public JSONObject loginUser(String userEmail, String userPsw) {
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("tag", login_tag));
params.add(new BasicNameValuePair("email", userEmail));
params.add(new BasicNameValuePair("password", userPsw));
JSONObject json = jsonParser.getJsondataFromUrl(params);
//Log.d("tag", json.toString());
return json;
}
following is the actual webservice class
public void getJsondataFromUrl(List<NameValuePair> params) {
{
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResp = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResp.getEntity();
inStream = httpEntity.getContent();
//Log.d(tag, inStream.toString());
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader bufferReader = new BufferedReader(new InputStreamReader
(inStream, "iso-8859-1"), 8);
StringBuilder strBuilder = new StringBuilder();
String line = null;
while ((line = bufferReader.readLine()) != null) {
strBuilder.append(line + "n");
}
inStream.close();
json = strBuilder.toString();
//Log.d("JSON", json);
} catch (Exception e) {
e.printStackTrace();
}
// try parse the string to a JSON object
try {
jsonObj = new JSONObject(json);
} catch (JSONException e) {
e.printStackTrace();
}
return jsonObj;*/
}
Thanks in advance
解决方案
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.login);
context=this;
Log.v(TAG+"onCreate", "OnCreate Called");
username = (EditText)findViewById(R.id.editText_user);
password = (EditText)findViewById(R.id.editText_psw);
btngo = (ImageButton)findViewById(R.id.imageButton_go);
btngo.setOnClickListener(this);
}
@Override
public void onClick(View v) {
Log.v(TAG+"onClick", "onClick Called");
if(v== btngo)
{
user=username.getText().toString().trim();
psw=password.getText().toString().trim();
dialog = ProgressDialog.show(context, "", "Please! Wait...",true);
GetResult result = new GetResult();
result.execute();
}
}
}
private class GetResult extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
Log.v(TAG + ".doInBackground", "doInBackground method call");
String response1 = null;
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("url");
// Log.d("response", "WORKING");
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("webservice", "1"));
nameValuePairs.add(new BasicNameValuePair("Email_ID", user));
nameValuePairs.add(new BasicNameValuePair("Password",psw));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
InputStream is = response.getEntity().getContent();
WebHelper webHelper = new WebHelper();
response1 = webHelper.convertStreamToString(is);
Log.v(TAG+".doInBackground", "json response is:" + response1);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return response1;
}
@Override
protected void onPostExecute(String result) {
Log.v(TAG + ".onPostExecute", "onPostExecute method call");
dialog.dismiss();
Log.v(TAG+".onPostExecute", "json response is:" + result);
/* Intent intent= new Intent(LoginActivity.this, ChoiceExamActivity.class);
startActivity(intent);
*/
if(result!=null){
try {
//JSONTokener tokener = new JSONTokener(result);
JSONObject resultObjct = new JSONObject(result);
String user_id=resultObjct.getString("User_ID");
if(user_id.equalsIgnoreCase("0"))
{
ExamUtil.showAlert(LoginActivity.this,"Incorrect User name or password");
}
else
{
String firstname = resultObjct.getString("First_Name");
Log.v(TAG+".onPostExecute", "user id is:" + user_id);
Log.v(TAG+".onPostExecute", "firstname is:" + firstname);
Intent intent= new Intent(LoginActivity.this, ChoiceExamActivity.class);
startActivity(intent);
}
} catch (JSONException e) {
e.printStackTrace();
}
catch (Exception e) {
e.printStackTrace();
}
}
else{
ExamUtil.showAlert(LoginActivity.this,"We have some problem in processing request, try again.");
}
}
}
}
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