How to access Map contents in jsp page

[Rupa Katkar]

Hi,

I have stored the contents of database table in map. & now i want to access this contents of map in
jsp page.

How should i access.
Please help me.

Thanks,
Rupa.

[Teena George]

Hi Rupa,

I hope you are using EL in your JSP pages. You can access a map like this:

 ${mapName.key}   

or

 ${mapName["key"]}   

When you use the mapName.key format make sure your key name is a valid java identifier.
For example, if you have User-Agent in your request header, you can not access it using

  ${header.User-Agent}  

because it takes '-' as the minus operator.
Please let me know if you have any difficulty.
HTH,
Teena

[Rupa Katkar]

Teena George wrote:Hi Rupa,

I hope you are using EL in your JSP pages. You can access a map like this:

 ${mapName.key}   

or

 ${mapName["key"]}   

When you use the mapName.key format make sure your key name is a valid java identifier.
For example, if you have User-Agent in your request header, you can not access it using

  ${header.User-Agent}  

because it takes '-' as the minus operator.
Please let me know if you have any difficulty.
HTH,
Teena

Hi Teena,
Thanks for your response.
Actually I am not using EL, can you please help me some more regarding using EL.

Thanks,
Rupa.

[Swastik Dey]

this might be helpful

http://java.sun.com/j2ee/1.4/docs/tutorial/doc/JSPIntro7.html

[Teena George]

You can also grab a Head First Servlets and JSP book. It will give you clear idea of EL (and many other topics).

[Rupa Katkar]

Rupa Katkar wrote:

Teena George wrote:Hi Rupa,

I hope you are using EL in your JSP pages. You can access a map like this:

 ${mapName.key}   

or

 ${mapName["key"]}   

When you use the mapName.key format make sure your key name is a valid java identifier.
For example, if you have User-Agent in your request header, you can not access it using

  ${header.User-Agent}  

because it takes '-' as the minus operator.
Please let me know if you have any difficulty.
HTH,
Teena

Hi Teena,
Thanks for your response.
Actually I am not using EL, can you please help me some more regarding using EL.

Thanks,
Rupa.

Hi Teena ,

Actually this is my code snippet, where i am using
map..

        if(hm_b01.isEmpty())  {   // here hm_b01 is the Map
            
    // Retrieving batch no, no. of docs & total receipt amount from B01 table.
            PreparedStatement st2 = conn.prepareStatement("SELECT BATCH_NO, NO_OF_DOCS, TOTAL_RECEIPT_AMOUNT FROM TBL_B01 ");
            ResultSet rs2 = st2.executeQuery();  
                while(rs2.next())   
                {     
                        Batch_B60 b = new Batch_B60(rs2.getString(1),rs2.getInt(2),rs2.getDouble(3));
                       
                        hm_b01.put(b.b01_batch,b); // Putting the retrieved values in Map "hm_b01"
                         System.out.println("Executing B01");   
                }   
             rs2.close();
    
         }

mean here i am storing object of Batch_B60 class i.e. "b" to the map.
& now how should i access the contents of this map in jsp.

Thanks,
Rupa.

[Rupa Katkar]

Rupa Katkar wrote:

Rupa Katkar wrote:

Teena George wrote:Hi Rupa,

I hope you are using EL in your JSP pages. You can access a map like this:

 ${mapName.key}   

or

 ${mapName["key"]}   

When you use the mapName.key format make sure your key name is a valid java identifier.
For example, if you have User-Agent in your request header, you can not access it using

  ${header.User-Agent}  

because it takes '-' as the minus operator.
Please let me know if you have any difficulty.
HTH,
Teena

Hi Teena,
Thanks for your response.
Actually I am not using EL, can you please help me some more regarding using EL.

Thanks,
Rupa.

Hi Teena ,

Actually this is my code snippet, where i am using
map..

        if(hm_b01.isEmpty())  {   // here hm_b01 is the Map
            
    // Retrieving batch no, no. of docs & total receipt amount from B01 table.
            PreparedStatement st2 = conn.prepareStatement("SELECT BATCH_NO, NO_OF_DOCS, TOTAL_RECEIPT_AMOUNT FROM TBL_B01 ");
            ResultSet rs2 = st2.executeQuery();  
                while(rs2.next())   
                {     
                        Batch_B60 b = new Batch_B60(rs2.getString(1),rs2.getInt(2),rs2.getDouble(3));
                       
                        hm_b01.put(b.b01_batch,b); // Putting the retrieved values in Map "hm_b01"
                         System.out.println("Executing B01");   
                }   
             rs2.close();
    
         }

mean here i am storing object of Batch_B60 class i.e. "b" to the map.
& now how should i access the contents of this map in jsp.

Thanks,
Rupa.

Hi all,
pl. give me reply.

[Rupa Katkar]

Teena George wrote:Hi Rupa,

I hope you are using EL in your JSP pages. You can access a map like this:

 ${mapName.key}   

or

 ${mapName["key"]}   

When you use the mapName.key format make sure your key name is a valid java identifier.
For example, if you have User-Agent in your request header, you can not access it using

  ${header.User-Agent}  

because it takes '-' as the minus operator.
Please let me know if you have any difficulty.
HTH,
Teena

Hi ,

i am facing problem in passing the Map to jsp page,
how should i forward the map to jsp page.
& then how should i access it using EL.

[Teena George]

Hi Rupa,

Sorry for the delayed response. I was caught up with some work. I hope you have already cracked it But, even if you haven't, here is how i tried it.

  
<jsp:useBean id="DemoClass" scope="session"  class="com.demo.DemoClass"/>
<h1>welcome to first jsp</h1>
${DemoClass.mapObj.Teena}
</body> 

Please let me know if this is not working for you.
Best Regards,
Teena

[Rupa Katkar]

Teena George wrote:

Hi Rupa,

Sorry for the delayed response. I was caught up with some work. I hope you have already cracked it But, even if you haven't, here is how i tried it.

  
<jsp:useBean id="DemoClass" scope="session"  class="com.demo.DemoClass"/>
<h1>welcome to first jsp</h1>
${DemoClass.mapObj.Teena}
</body> 

Please let me know if this is not working for you.
Best Regards,
Teena

Hi Teena,
Actually i am not using bean & i am not knowing beans.
in my servlet program i am having this code.

        else{
            CompareFiles com=new CompareFiles();   // this is the class where i am having MAP
            com.check();                                           //in this function i am using MAP
                       
            RequestDispatcher rd = request.getRequestDispatcher("/EL.jsp");  
            rd.forward(request,response);
              }

in CompareFiles class

public void check()
{
    
    Connection conn = null;
    {
        try {
            conn = ORConnection.getORConnection();
            System.out.println("Connected to Oracle");
        } catch (SQLException e) {  System.out.println("error while connecting to Oracle");   }
        
    
        try{
    
        System.out.println("Executing Query");
           
        if(hm_b60_group.isEmpty())  {
             
    // Getting batch no., count & Sum of receipt amount for that batch from B60 table.
            PreparedStatement st = conn.prepareStatement("SELECT BATCH_NO,COUNT(*)NUM, SUM(RECEIPT_AMOUNT)SUM FROM TBL_B60 GROUP BY BATCH_NO");
            ResultSet rs = st.executeQuery();  
                while(rs.next())   
                {     
                        Batch_B60 b = new Batch_B60(rs.getString(1),rs.getInt(2),rs.getDouble(3));
                        hm_b60_group.put(b.b01_batch,b); // Putting the retrieved values in Map "hm_b60_group"
                             
                } 
             rs.close();
    
        }
        
      if(hm_b60.isEmpty())  {
    //Retrieving batch_no, consumer no & cd from B60 table.
             PreparedStatement st1 = conn.prepareStatement("SELECT BATCH_NO,CONSUMER_NO,CD FROM TBL_B60 ");
             ResultSet rs1 = st1.executeQuery();  
             while(rs1.next())   
                {     
                 
                  Batch_B60 b = new Batch_B60(rs1.getString(1), rs1.getString(2),rs1.getInt(3));
                  hm_b60.put(b.b60_batch,b);  // Putting the retrieved values in Map "hm_b60"
                                           
                } 
             rs1.close();
             }

   } 

in the above code i am using two maps.
Now i am not getting how to pass this maps to jsp page.

I tried a lot , but i am not getting it.
Pl. help me teena.
Thanks in advance.
Rupa.

[Patricia Samuel]

You have to return "hm_b60" this object from your check method or have to pass it in check() method.

After this use the following code - assuming you will return the map from check method

   
HttpSession objSession = req.getSession();
objSession.setAttribute("map",hm_b60);

 

and in your jsp take this attribute from request and then iterate the map as

   Iterator iter = map.keySet().iterator();
while(iter.hasNext()){
key =iter.next();

value = map.get(key);

}
 

As a suggestion, we should use EL for Jsps. I am not sure why are you using this old way of writing a JSP.

Hope this helps. Let me know if you still stuck.


Regards
Patricia

[Rupa Katkar]

Patricia Samuel wrote:You have to return "hm_b60" this object from your check method or have to pass it in check() method.

After this use the following code - assuming you will return the map from check method

   
HttpSession objSession = req.getSession();
objSession.setAttribute("map",hm_b60);

 

and in your jsp take this attribute from request and then iterate the map as

   Iterator iter = map.keySet().iterator();
while(iter.hasNext()){
key =iter.next();

value = map.get(key);

}
 

As a suggestion, we should use EL for Jsps. I am not sure why are you using this old way of writing a JSP.

Hope this helps. Let me know if you still stuck.


Regards
Patricia

Hi,
Actually i want to use EL only, but if you observed my prev. code, i am not getting that how should i pass the map to jsp page,
As i am calling the function in CompareFiles.java file, i am not getting how should i pass this map to jsp.
Pl. give me reply earliest possible.
Thanks,
Rupa.

[Patricia Samuel]

Isn't this line help -

  HttpSession objSession = req.getSession();  
 objSession.setAttribute("map",hm_b60);  

and you can access this attribute with the help of request parameter in JSP.

  ${map.....}  

Please let me know if you face any problem using it.

[Praneeth Thiruveedhula]

Hi,
How to access map contents in the jsp..?

test.jsp

  

<%-- first import the Map interface into your jsp --%>
<%@ page import="java.util.Map" %>

u may use scriptlet for database code.
or u may use <jsp:usebean> tag for getting data from database.