public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
String user = req.getParameter("id");
resp.setContentType("text/plain");
PrintWriter writer = resp.getWriter();
writer.write("value"+user);}}
**********************************************************************
**Android side code**
EditText numDisplay;
Button calculateNow;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
numDisplay= (EditText)findViewById(R.id.editText1);
calculateNow = (Button)findViewById(R.id.button1);
calculateNow.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
{
new MyAsyncTask().execute(numDisplay.getText().toString());
} }
} );
}
private class MyAsyncTask extends AsyncTask<String, Integer, Double>{
protected Double doInBackground(String... params) {
postData(params[0]);
return null;
}
protected void onPostExecute(Double result){
Toast.makeText(getApplicationContext(), "command sent", Toast.LENGTH_LONG).show();
}
protected void onProgressUpdate(Integer... progress){
//pb.setProgress(progress[0]);
}
public void postData(String valueIWantToSend) {
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://primecalculation.appspot.com/");
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("id", valueIWantToSend));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
} catch (IOException e) {
// TODO Auto-generated catch block
}
}
我正在向 servlet 发送值，但在 servlet 中我得到的是空值。
从 android 端发送数据。代码从 android 和 java 服务器端正确编译。 当我在网页上运行该程序时，我得到空值。
感谢任何帮助
最佳答案
您在服务器端代码中使用 doGet，但在客户端调用 HttpPost。更改其中任何一个。
服务器代码:
public void doPost(HttpServletRequest req, HttpServletResponse resp) {
...
}
或
客户端代码:
HttpGet httppost = new HttpGet("http://primecalculation.appspot.com/");
但不是两者兼而有之
关于java - 从android应用程序接收java servlet中的空值，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31705970/