这是我的java代码：
@SuppressLint({ "ParserError", "ParserError" })
public class MainActivity extends Activity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
InputStream is=null;
String result = "";
TextView tv=(TextView)findViewById(R.id.tv);
//the year data to send
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("name","shrey"));
//http post
try{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://10.0.2.2:8081/onlinechat");
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
}
catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//convert response to string
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();
tv.setText(result);
}catch(Exception e){
Log.e("log_tag", "Error converting result "+e.toString());
}
//parse json data
/* try{
JSONArray jArray = new JSONArray(result);
for(int i=0;i<jArray.length();i++){
JSONObject json_data = jArray.getJSONObject(i);
Log.i("log_tag" , "name: "+json_data.getString("user")
);
}
}
catch (JSONException e)
{
Log.e("log_tag", "Error parsing data "+e.toString());
}
*/
}
}
这是我的Servlet代码：
public class android extends HttpServlet {
/**
* Processes requests for both HTTP
* <code>GET</code> and
* <code>POST</code> methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String user=request.getParameter("name").toString();
/* BufferedReader reader = new BufferedReader( new InputStreamReader(request.getInputStream() ) );
String res = reader.readLine();
while( null != res )
{
System.out.println( res );
res = reader.readLine();
}
/*InputStream is = new BufferedInputStream(request.getInputStream());
byte[] buf = new byte[8096];
int bytesRead;
System.out.println("readbuf "+ is.read( buf ));
while( ( bytesRead = is.read( buf ) ) != -1 )
os.write( buf, 0, bytesRead ); */
out.print("welcome"+user);
out.println("success");
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP
* <code>GET</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP
* <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
我在清单中添加了 Internet 权限，但它仍然没有运行。这是调试器解决后我的 logcat
07-31 13:45:50.874: E/log_tag(666): Error converting result java.lang.NullPointerException