java get average for all items in a selected category

Question

How can I get the average salary of all employees in the selected company? I first select the company and then pass the id and based on that id, i get all employees in there and

Answer 1

You could sum the salaries up and then divide by the number of employees:

<% List<Employee> employees = company.getEmployees();
   double sum=0.0;
%>
<table border="1">

    <tr>
        <td>ID</td>
        <td>Name</td>                        
        <td>Salary</td>             
    </tr>        
    <%
for(int i=0; i <employees.size(); i++){
    sum += employees.get(i).getSalary();
%> 
        <tr>      
            <td><%=employees.get(i).getId()%></td>
            <td><%=employees.get(i).getNom()%></td>                
            <td><%=employees.get(i).getSalary()%></td>  
        </tr>
    <% } %>
</table> 

//get the average salary of all employees
<p>Average salary of all employees in this company:<%=sum/(double)employees.size()%> </p>

Having said that, I urge you to reconsider before going down that road. Having code inside your JSP will severely hinder your chances of maintaining it if it gets any bigger than 1-2 pages. All your business logic should happen in your code (e.g. inside your servlets) and in JSPs only display the information.