HTML form method POST calls java servlet doGet method
Question
I have an HTML form like this:
form.html:
<html>
<body>
your name is :<br><br>
<form ACTION="../post2" METHOD="POST">
<input name="name" type="text" id="name"/>
<input name="send" type="submit" value="send"/>
</form>
</body>
<html>
The servlet to serve this request:
post2.class:
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.http.*;
public class post2 extends HttpServlet
{
protected void doDo(HttpServletRequest request,HttpServletResponse response)
throws IOException{
String name = request.getParameter("name");
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<HTML><BODY>");
out.println("<H2>hello "+name+"</H2>");
out.println("<BR><BR>");
out.println("info:");
out.println("<BR><BR>");
out.println("<H2>metoda GET</H2>");
out.println("<BR><BR>");
out.println("SERVER_NAME="+request.getServerName()+"<BR>");
out.println("REQUEST_METHOD="+request.getMethod()+"<BR>");
out.println("QUERY_STRING="+request.getQueryString()+"<BR>");
out.println("REMOTE_HOST="+request.getRemoteHost()+"<BR>");
out.println("REMOTE_ADDR="+request.getRemoteAddr());
out.println("</BODY></HTML>");
}
@Override
public void doGet(HttpServletRequest request,HttpServletResponse response)
throws IOException {
doDo(request,response);
}
@Override
public void doPost(HttpServletRequest request,HttpServletResponse response)
throws IOException {
doDo(request,response);
}
}
and the result is :
hello null
info:
SERVER_NAME=localhost
REQUEST_METHOD=GET
QUERY_STRING=null
REMOTE_HOST=127.0.0.1
REMOTE_ADDR=127.0.0.1
what is wrong ? For me it seems that the servlet don't see post method from form. Please help, Im completly have no idea why it not working properly...
the result from the wireshark:
648 126.229267 87.105.184.89 192.168.1.100 HTTP 557 POST /post2 HTTP/1.1 (application/x-www-form-urlencoded)
953 379.456916 192.168.1.100 87.105.184.89 HTTP 239 HTTP/1.1 302 Moved Temporarily
955 379.462518 192.168.1.100 87.105.184.89 HTTP 470 GET /post2/ HTTP/1.1
957 379.463979 192.168.1.100 87.105.184.89 HTTP 431 HTTP/1.1 200 OK (text/html)
routing logic:
tomcat\\webapps\\ROOT\\form.html --> \\tomcat\\webapps\\post2\\WEB-INF\\classes\\post2.class
4 answers
solution1
2 ACCPTED 2012-01-01 22:36:42
Could this be due to a redirect? If "/post2" redirects to "/post2/" your POST request would be transformed into a GET, losing all post data.
Try accessing "/post2" directly in your browser and see what happens.
solution2
0 2012-01-01 22:22:55
You need to add a value attribute to the input tag:
<input name="name" type="text" id="name" value=""/>
And put (enter by typing) a value in there - by default blank fields are not submitted.
For simplicity, try this, which pre-sets the value:
<input name="name" type="text" id="name" value="john"/>
solution3
0 2012-01-01 22:23:02
发生null问题是因为您没有将表单提交到服务器。
solution4
-1 2014-05-07 17:19:22
这可以解决您的问题：
String name = request.getParameter("name").toString();
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