How to iterate returned hashmap and get all values using jsp

Question

This is my function in the bean class-- product.java Im selecting the certain details from database and putting the values from database in a hashmap. HashMap is a type of Class Products.

 public HashMap<String,Products> showProducts()
{  
    HttpServletRequest request = null;
    PreparedStatement preparedStatement;
    HashMap<String,Products>productMap=new HashMap<String,Products>();
    try 
    {
        preparedStatement = con.prepareStatement("select * from productdetails where producttype='toy'");

        ResultSet resultSet=preparedStatement.executeQuery();
        Products toy=new Products();
        while(resultSet.next()){
            toy.setProductId(resultSet.getInt(1));
            toy.setProductName(resultSet.getString(2));
            toy.setProductPrice(resultSet.getInt(3));
            productMap.put("toy",toy);

            request.setAttribute("productSessionMap",productMap);  
        }
                }

    catch(Exception e)
    {
        e.printStackTrace();
    }
    return productMap;

}

This is the jsp page

            <%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
    <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
    <%@page import="java.util.Set"%>
    <%@page import="java.util.HashMap"%>
            <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
    "http://www.w3.org/TR/html4/loose.dtd">
      <html>
      <head>
  <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
 <title>Insert title here</title>
 </head>

<body>
  Welcome!!!! <c:out value="${sessionScope.loginBean.userName}"></c:out>
   <jsp:useBean id="loginBean" class="com.training.entity.ShoppingCart" 
  scope="session"></jsp:useBean>
    <jsp:setProperty property="*" name="loginBean"/>

  <c:set var="status" value="${loginBean.showProducts()}"></c:set>
  <c:set var="keys" value="${status.keySet()}"></c:set>
  <c:out value="${status.toString()}"></c:out>   <!-- This line displays last value of hashmap-!>

 <c:forEach var="type" items="${productSessionMap}">
 <c:out value="${type[keys]}"></c:out>


 </c:forEach>


  </body>
  </html>

I want to iterate and display each value and key in the hashmap in jsp withous using scriptlet tags. Please help me with this.

Even i tried using scriplet tag.. But i am only getting the last value in the hashmap when iterating..

  <%
  ShoppingCart ob=new ShoppingCart();

  HashMap<Integer,Products>newproductMap=new HashMap<Integer,Products>();
  newproductMap=ob.showProducts();
  Set<Integer>set = newproductMap.keySet();
 for(Integer ent:set){
 String name=newproductMap.get(ent).getProductName().toString();%>
  <%=name%>
  <%-- <%String value = ent.getValue().toString();%>
  <%=value%>
  --%>
 <%}%>

gzp___ · Answer 1 · 2017-12-02T18:35:12.377

Every item in the iteration is an istance of Map.Entry.

In this case your type var will be a Map.Entry.

you should first assign a new key to each new Product

 while(resultSet.next()){
                toy.setProductId(resultSet.getInt(1));
                toy.setProductName(resultSet.getString(2));
                toy.setProductPrice(resultSet.getInt(3));
                productMap.put(""+resultSet.getInt(1),toy);//here assign a new unique key
            }
 //this must be moved outside of the while loop
 request.setAttribute("productSessionMap",productMap);

Then you can access the value of each Map.Entry with ${type.value} then each attribute of the value (type Products) can be accessed invoking its getter method i.e ${type.value.productName}

<table>
            <tbody>
                <tr>
                    <th>Product Id</th>
                    <th>Product Name</th>
                    <th>Product Price</th>
                </tr>
                <c:forEach items="${requestScope.productSessionMap}" var="type">
                    <tr>
                        <td>
                            <c:out value="${type.key}"></c:out><!-- this is the key you specified in the map i.e. 'productId' -->
                        </td>
                        <td>
                            <c:out value="${type.value.productName}"></c:out>
                        </td>
                        <td>
                            <c:out value="${type.value.productPrice}"></c:out>
                        </td>
                    </tr>
                </c:forEach>
            </tbody>
        </table>

But is there any way to do this in jsp without using scriplet tags. — Amrutha Jaya Raj, Dec 01 '17 at 17:22
I used duplicate key in hashmap. Thanks for finding that out. — Amrutha Jaya Raj, Dec 01 '17 at 17:26
Try something like this productId is ${product.key} <% Products p = (Products)pageContext.getAttribute("p"); %> productPrice is: <%=p.productPrice%> productName is: <%=p.productName%> — gzp___, Dec 01 '17 at 17:41
I have corrected the answer, as you want to avoid using scriplet tags — gzp___, Dec 02 '17 at 18:35

How to iterate returned hashmap and get all values using jsp

1 Answers1