Populate JSP Form

Question

How to populate a form when JSP is called first time ? I need to process an XML file when a page is refreshed & populate the form in the JSP page?(not using frameworks)

Answer 1

Sure - just set initial values in the bean properties that you are exposing in your form. Then use expression language to populate the fields, such as

<input type="text" value="${bean.myProperty}"/>

Answer 2

You have 2 options:

1. Use <jsp:usebean>, let the bean fill itself in the constructor.

   <jsp:useBean id="bean" class="com.example.Bean" />
   ...
   <input name="foo" value="${fn:escapeXml(bean.foo)}">
   <input name="bar" value="${fn:escapeXml(bean.bar)}">
   

   The fn:escapeXml() is not mandatory for the functioning, but it's mandatory to prevent XSS attacks if you're redisplaying user-controlled input in a HTML page.

2. Use the doGet() method of a Servlet.

   Bean bean = new Bean();
   request.setAttribute("bean", bean);
   request.getRequestDispatcher("page.jsp").forward(request, response);
   

   and use the URL to servlet in browser address bar instead of the JSP's one. You can use the same code in JSP page as above, expect of the jsp:useBean line.

Way 1 is more the oldschool and student's way. Way 2 is more MVC oriented and preferred in this particular case since you seem to be doing more than just populating a bean.

See also:

• JSP tag info page - contains useful tutorial links at bottom