You are creating a library of custom tags that mimic the HTML form tags. When the user submits a form that fails validation, the
JSP form is forwarded back to the user. The <t:textField> tag must support the ability to re-populate the form field with the request parameters from the user’s last request. For example, if the user entered “Samantha” in the text field called firstName, then the form is re-populated like this
<input type = “text” name = ‘firstName’ value = ‘Samantha’>
Which tag handler method will accomplish this goal?
Ans. public int doStartTag() throws JspException {
Servletrequest request = pageContext.getRequest();
String value = request.getParameter(this.name);
If (value == null) value = “”;
JspWriter out = pageContext.getOut();
try {
out.write (String.format (INPUT, this.name, value));
} (Exception e) {throw new JspException (e) ;}
return SKIP_BODY;
}
private static String INPUT = “<input type = ‘text’ name = ‘%s’ value = ‘%s’>”;
Can anybody explain me how this code works?
