如何在Android中从AsyncTask实现Webservice连接?
我有个问题 我从几个小时开始就在做这个,但没有结果:如何在Android中从AsyncTask实现Webservice连接?,android,rest,Android,Rest,我有个问题 我从几个小时开始就在做这个,但没有结果: public void getData(){ new Task().execute(); } class Task extends AsyncTask<Void, Void, String>{ @Override protected String doInBackground(Void... noargs) { return null; } protect
public void getData(){
new Task().execute();
}
class Task extends AsyncTask<Void, Void, String>{
@Override
protected String doInBackground(Void... noargs) {
return null;
}
protected void onPostExecute(String result){
DefaultHttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://www.omdbapi.com/?t=True%20Grit&y=1969");
try {
HttpResponse response = client.execute(request);
BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
String line = "";
StringBuffer zeile = new StringBuffer("");
while((line = rd.readLine()) != null){
zeile.append(line);
}
String res = zeile.toString();
Toast toast = Toast.makeText(getApplicationContext(), res, Toast.LENGTH_SHORT);
toast.show();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void getData(){
新任务().execute();
}
类任务扩展了异步任务{
@凌驾
受保护的字符串doInBackground(无效…无args){
返回null;
}
受保护的void onPostExecute(字符串结果){
DefaultHttpClient=新的DefaultHttpClient();
HttpGet请求=新建HttpGet(“http://www.omdbapi.com/?t=True%20Grit&y=1969");
试一试{
HttpResponse response=client.execute(请求);
BufferedReader rd=新的BufferedReader(新的InputStreamReader(response.getEntity().getContent());
字符串行=”;
StringBuffer zeile=新的StringBuffer(“”);
而((line=rd.readLine())!=null){
zeile.append(行);
}
String res=zeile.toString();
Toast Toast=Toast.makeText(getApplicationContext(),res,Toast.LENGTH\u SHORT);
toast.show();
}捕获(客户端协议例外e){
//TODO自动生成的捕捉块
e、 printStackTrace();
}捕获(IOE异常){
//TODO自动生成的捕捉块
e、 printStackTrace();
}
}
}
每次(通过按钮调用getDate()时)我都会收到一个异常,手机上会显示“不幸的是,应用程序完成了”。你知道我的错在哪里吗
异常是:NetworkOnMainThreadException,如何解决它
非常感谢你 在UI线程上运行异步任务的
onPostExecute()
和onPreExecute()
。将网络代码从onPostExecute()
移动到doInBackground()
您应该将所有与网络相关的代码移动到doInBackground()
,并在onPostExecute()
内处理网络调用的结果。下面是您的代码的外观:
class Task extends AsyncTask<Void, Void, String>{
@Override
protected String doInBackground(Void... noargs) {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://www.omdbapi.com/?t=True%20Grit&y=1969");
try {
HttpResponse response = client.execute(request);
BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
String line = "";
StringBuffer zeile = new StringBuffer("");
while((line = rd.readLine()) != null){
zeile.append(line);
}
String res = zeile.toString();
return res;
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return "";
}
protected void onPostExecute(String result){
Toast toast = Toast.makeText(getApplicationContext(), result, Toast.LENGTH_SHORT);
toast.show();
}
}
类任务扩展了异步任务{
@凌驾
受保护的字符串doInBackground(无效…无args){
DefaultHttpClient=新的DefaultHttpClient();
HttpGet请求=新建HttpGet(“http://www.omdbapi.com/?t=True%20Grit&y=1969");
试一试{
HttpResponse response=client.execute(请求);
BufferedReader rd=新的BufferedReader(新的InputStreamReader(response.getEntity().getContent());
字符串行=”;
StringBuffer zeile=新的StringBuffer(“”);
而((line=rd.readLine())!=null){
zeile.append(行);
}
String res=zeile.toString();
返回res;
}捕获(客户端协议例外e){
//TODO自动生成的捕捉块
e、 printStackTrace();
}捕获(IOE异常){
//TODO自动生成的捕捉块
e、 printStackTrace();
}
返回“”;
}
受保护的void onPostExecute(字符串结果){
Toast Toast=Toast.makeText(getApplicationContext(),result,Toast.LENGTH\u SHORT);
toast.show();
}
}