CODEWITHSUNDEEP
javajsp
Kapil
Kapil

Reputation: 350

How to check condition with JSP variable?

Hello i am New jsp i want to check condition in jsp. whether value is null or not.? i have write following code in jsp page

   <% String s = request.getParameter("search"); %>
    <%=s %>
    <% if (<%=s ==null) { %> 
     <div>textbox is empty</div>

   <% } else { %>
   <div>textbox value..
    <% } %>

i get textbox value in variable if textbox value is null then it should display first message othervise second. tell me how to do?

Upvotes: 0

Views: 46125

Answers (6)

Bhagawat
Bhagawat

Reputation: 468

In jsp, it is easy to check whether a variable is empty or not.

String search;
if(search.isEmpty()){
out.println("The variable is empty ?");
}
else{
out.println("The variable is Not empty ?");  
}

Upvotes: 0

AllTooSir
AllTooSir

Reputation: 49372

The best way to do it is with JSTL. Please avoid scriptlets in JSP.

<c:choose>
  <c:when test="${empty search}">
   <div>textbox is empty</div>
  </c:when>
  <c:otherwise>
    <div>textbox value is ${search}</div>
  </c:otherwise>
</c:choose>

Upvotes: 9

ntstha
ntstha

Reputation: 1173

<% String s = request.getParameter("search"); 
     if (s ==null) { %> 
     <div>textbox is empty</div>

   <% } else { %>
   <div><span><%=s%></span></div>
    <% } %>

edited to include empty string

<% 
       String s="";
     if(request.getParameter("search")!=null)
      {
          s=request.getParamater("search");
      }
     if(s.trim().length()==0)
        {%>
           <div>Empty Field</div>
        <%}
          else{%>
              <div><span><%=s%></div>
           <%}%>

Upvotes: 2

harsh
harsh

Reputation: 7692

    <% String s = request.getParameter("search"); %>
    <%=s %>
    <% if (s==null || s.isEmpty()) { %> 
     <div>textbox is empty</div>

   <% } else { %>
   <div>textbox value..
    <% } %>

Upvotes: 5

NilsH
NilsH

Reputation: 13821

Does it even compile? <% if (<%=s ==null) { %> should at least be 

<% if (s == null) { %>

If you want to check for empty string as well, do 

<% if(s == null || s.trim().length == 0) { %>

Upvotes: 3

Alpesh Gediya
Alpesh Gediya

Reputation: 3794

<% String s = request.getParameter("search"); %>
    <%=s %>
    <% if (s ==null) { %> 
     <div>textbox is empty</div>

   <% } else { %>
   <div>textbox value..
    <% } %>

Upvotes: 1

Related Questions