Android 如何从AsyncTask http post获取结果?
假设我有文本输入和输出以及要发布的按钮。因此,我将一些json(nameValuePairs)发布到给定的API中。我知道如何通过严格模式线程策略技巧来实现这一点,但是,我需要AsyncTask来使用ProgressBarAndroid 如何从AsyncTask http post获取结果?,android,android-asynctask,Android,Android Asynctask,假设我有文本输入和输出以及要发布的按钮。因此,我将一些json(nameValuePairs)发布到给定的API中。我知道如何通过严格模式线程策略技巧来实现这一点,但是,我需要AsyncTask来使用ProgressBar public class MainActivity extends Activity { //Toast.makeText(getBaseContext(), str_text_input, Toast.LENGTH_LONG).show(); public String
public class MainActivity extends Activity {
//Toast.makeText(getBaseContext(), str_text_input, Toast.LENGTH_LONG).show();
public String URL = "someurl";
EditText text_input;
EditText output;
ProgressBar progressbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.user_interface);
text_input = (EditText) findViewById(R.id.text_input);
output = (EditText) findViewById(R.id.text_output);
progressbar = (ProgressBar) findViewById(R.id.progressBar);
progressbar.setVisibility(View.GONE);
}
public void button_called(View view) {
progressbar.setVisibility(View.VISIBLE);
String txt = text_input.getText().toString();
sendPostRequest(txt, "somecheckcode", Integer.toString(int1), Integer.toString(int2));
// Here I want result of posting http request = Response
output.setText(Response);
}
String sendPostRequest(String txt, String Code, String dir, String topic ) {
class SendPostReqAsyncTask extends AsyncTask<String, Void, String>{
@Override
protected String doInBackground(String... params) {
String text = params[0];
String code = params[1];
String direction = params[2];
String topics = params[3];
String finalResult = "";
//System.out.println("*** doInBackground ** paramUsername " + paramUsername + " paramPassword :" + paramPassword);
HttpClient httpClient = new DefaultHttpClient();
// In a POST request, we don't pass the values in the URL.
//Therefore we use only the web page URL as the parameter of the HttpPost argument
HttpPost httpPost = new HttpPost(URL);
// Because we are not passing values over the URL, we should have a mechanism to pass the values that can be
//uniquely separate by the other end.
//To achieve that we use BasicNameValuePair
//Things we need to pass with the POST request
BasicNameValuePair srctxt = new BasicNameValuePair("param1", text);
BasicNameValuePair chkcode = new BasicNameValuePair("param2", code);
BasicNameValuePair direct = new BasicNameValuePair("param3", direction);
BasicNameValuePair sbjbs = new BasicNameValuePair("param4", topics);
// We add the content that we want to pass with the POST request to as name-value pairs
//Now we put those sending details to an ArrayList with type safe of NameValuePair
List<NameValuePair> nameValuePairList = new ArrayList<NameValuePair>();
nameValuePairList.add(srctxt);
nameValuePairList.add(chkcode);
nameValuePairList.add(direct);
nameValuePairList.add(sbjbs);
try {
// UrlEncodedFormEntity is an entity composed of a list of url-encoded pairs.
//This is typically useful while sending an HTTP POST request.
UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(nameValuePairList, HTTP.UTF_8);
// setEntity() hands the entity (here it is urlEncodedFormEntity) to the request.
httpPost.setEntity(urlEncodedFormEntity);
try {
// HttpResponse is an interface just like HttpPost.
//Therefore we can't initialize them
HttpResponse httpResponse = httpClient.execute(httpPost);
// According to the JAVA API, InputStream constructor do nothing.
//So we can't initialize InputStream although it is not an interface
InputStream inputStream = httpResponse.getEntity().getContent();
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
StringBuilder stringBuilder = new StringBuilder();
String bufferedStrChunk = null;
while((bufferedStrChunk = bufferedReader.readLine()) != null){
stringBuilder.append(bufferedStrChunk);
}
finalResult = stringBuilder.toString();
return stringBuilder.toString();
} catch (ClientProtocolException cpe) {
System.out.println("First Exception of HttpResponese :" + cpe);
cpe.printStackTrace();
} catch (IOException ioe) {
System.out.println("Second Exception of HttpResponse :" + ioe);
ioe.printStackTrace();
}
} catch (UnsupportedEncodingException uee) {
System.out.println("An Exception given because of UrlEncodedFormEntity argument :" + uee);
uee.printStackTrace();
}
return finalResult;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
}
}
SendPostReqAsyncTask sendPostReqAsyncTask = new SendPostReqAsyncTask();
sendPostReqAsyncTask.execute(txt, Code, dir, topic);
return "RESULT_I_WANTED";
}
公共类MainActivity扩展活动{
//Toast.makeText(getBaseContext(),str_text_input,Toast.LENGTH_LONG).show();
公共字符串URL=“someurl”;
编辑文本输入;
编辑文本输出;
ProgressBar ProgressBar;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.user\u界面);
text\u input=(EditText)findViewById(R.id.text\u input);
输出=(EditText)findViewById(R.id.text\u输出);
progressbar=(progressbar)findViewById(R.id.progressbar);
progressbar.setVisibility(View.GONE);
}
公共无效按钮_调用(视图){
progressbar.setVisibility(View.VISIBLE);
String txt=text_input.getText().toString();
sendPostRequest(txt,“somecheckcode”、Integer.toString(int1)、Integer.toString(int2));
//这里我想要发布http请求=响应的结果
output.setText(响应);
}
字符串sendPostRequest(字符串txt、字符串代码、字符串目录、字符串主题){
类SendPostReqAsyncTask扩展了AsyncTask{
@凌驾
受保护的字符串doInBackground(字符串…参数){
字符串文本=参数[0];
字符串代码=参数[1];
字符串方向=参数[2];
字符串主题=参数[3];
字符串finalResult=“”;
//System.out.println(“***doInBackground**paramUsername”+paramUsername+“paramPassword:+paramPassword”);
HttpClient HttpClient=新的DefaultHttpClient();
//在POST请求中,我们不传递URL中的值。
//因此,我们只使用网页URL作为HttpPost参数的参数
HttpPost HttpPost=新的HttpPost(URL);
//因为我们没有通过URL传递值,所以我们应该有一种机制来传递可以传递的值
//被另一端唯一地分开。
//为了实现这一点,我们使用BasicNameValuePair
//我们需要通过POST请求传递的内容
BasicNameValuePair srctxt=新的BasicNameValuePair(“参数1”,文本);
BasicNameValuePair chkcode=新的BasicNameValuePair(“参数2”,代码);
BasicNameValuePair direct=新的BasicNameValuePair(“参数3”,方向);
BasicNameValuePair sbjbs=新的BasicNameValuePair(“参数4”,主题);
//我们将希望与POST请求一起传递的内容添加为名称-值对
//现在,我们将那些发送详细信息的内容放在类型安全的NameValuePair的ArrayList中
List nameValuePairList=新的ArrayList();
nameValuePairList.add(srctxt);
nameValuePairList.add(chkcode);
nameValuePairList.add(直接);
nameValuePairList.add(sbjbs);
试一试{
//UrlEncodedFormEntity是由url编码对列表组成的实体。
//这在发送HTTP POST请求时通常很有用。
UrlEncodedFormEntity UrlEncodedFormEntity=新的UrlEncodedFormEntity(nameValuePairList,HTTP.UTF_8);
//setEntity()将实体(这里是urlEncodedFormEntity)交给请求。
setEntity(urlEncodedFormEntity);
试一试{
//HttpResponse是一个与HttpPost类似的接口。
//因此,我们无法初始化它们
HttpResponse HttpResponse=httpClient.execute(httpPost);
//根据JavaAPI,InputStream构造函数什么都不做。
//所以我们不能初始化InputStream,尽管它不是一个接口
InputStream InputStream=httpResponse.getEntity().getContent();
InputStreamReader InputStreamReader=新的InputStreamReader(inputStream);
BufferedReader BufferedReader=新的BufferedReader(inputStreamReader);
StringBuilder StringBuilder=新的StringBuilder();
字符串bufferedStrChunk=null;
while((bufferedStrChunk=bufferedReader.readLine())!=null){
追加(bufferedStrChunk);
}
finalResult=stringBuilder.toString();
返回stringBuilder.toString();
}捕获(客户端协议异常cpe){
System.out.println(“HttpResponse的第一个例外:“+cpe”);
printStackTrace();
}捕获(ioe异常ioe){
System.out.println(“HttpResponse的第二个例外:“+ioe”);
ioe.printStackTrace();
}
}捕获(不支持的编码异常uee){
System.out.println(“由于UrlEncodedFormEntity参数:“+uee”而给出的异常);
uee.printStackTrace();
}
返回最终结果;
}
@凌驾
受保护的void onPostExecute(字符串结果){
super.onPostExecute(结果);
}
}
SendPostReqAsyncTask SendPostReqAsyncTask=新建SendPostReqAsyncTask();
执行(txt,代码,目录,主题);
返回“我想要的结果”;
}
在“活动”中创建另一个方法,以设置输出文本并获取输入字符串参数,如下所示
public void setOutputText(String outputText) {
output.setText(outputText);
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
setOutputText(result);
}
然后在AsyncTask的onPostExecute方法中调用此方法,如下所示
public void setOutputText(String outputText) {
output.setText(outputText);
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
setOutputText(result);
}
公共类MainActivity扩展活动{
//Toast.makeText(getBaseContext(),str_text_input,Toast.LENGTH_LONG).show();
公共字符串URL=“someurl”;
编辑文本输入;
编辑文本输出;
ProgressBar ProgressBar;
@凌驾
赞成的意见