Untitled

<body>
  <%!
    String username=null;
    String password=null;
  %>
  <%
    Cookie [] cookies=request.getCookies();
    if(cookies!=null) {
      for (int i = 0; i < cookies.length; i++) {
        if (cookies[i].getName().equals("username")) {
          username = cookies[i].getValue();
        }
      }
    }
  %>
  <form action="/helloworld" method="post">
    <input type="text" name="name" value="<%=username%>">
    <input type="submit">
  </form>
  </body>

if(cookies!=null)

Servlet.service() for servlet [jsp] in context with path [] threw exception [An exception occurred processing JSP page /index.jsp at line 20

17:   %>
18:   <%
19:     Cookie [] cookies=request.getCookies();
20:     for(int i=0;i<cookies.length;i++){
21:       if(cookies[i].getName().equals("username")) {
22:         username=cookies[i].getValue();
23:       }