Using DAO ,TO Pattern without EJB

Hi,
I am developing a web application without EJB. I understand those patterns need not use EJB framework. However, it smees to me that without EJB, the role of TO may be simpler.
In my design, the meaning of TO is to separate the layer between business tier and data access tier. Upon doing some back-end enquiry, the DAO create related TO which can be translate to the business / veiw objects. And the caching will be done on Web tier but not TO layer instead.
Am I right? Would you please give some comments? Thanks a lot.

What is the best way to allow the client to
interact
with Entity objects, without exposing them. ShouldI
implement Value objects that are easily serialized
for transfer across the network?
If you are not using EJB or a distributed
architecture, you do not need DTO's or VO's. They
are an odious construct used to obviate the
shortcomings of remote method calls over anetwork.
I strongly disagree.
They are an obvious and easy model used when the
following characteristics of a system exist.
- Different layers.
- Related data items that are moved throughout the
layers.
- Different usage of the related data items by
different layers.
Yes, I agree. Note the qualification 'if you are not using a distributed architecture'.
None of that has anything to do with remote method
calls over a network. Point of fact the first time I
used them was in a stand alone application with no
network traffic except that needed by the database
driver itself.
Simply create your domain model objects as POJO's
s (plain ole Java objects). Persist and retrieve
your objects via DAO's (data access objects).Your
service layer (facade) will sit on top of thedomain
model, encapsulating method calls into logicalunits
of work.
And how exactly do you move the customer
name/customer address from the DAO to the GUI level?I am assuming the dedicated remoting product the OP specifid, Hessian, will handle moving between the tiers, or at least between the controller/view and the business tier.
- Saish

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Dear all,
I have to develop an application in Struts by using DAO design pattern ..........
Please give an example on Struts using DAO...................
Thank you
Please

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What is the best way to allow the client to
interact
with Entity objects, without exposing them. ShouldI
implement Value objects that are easily serialized
for transfer across the network?
If you are not using EJB or a distributed
architecture, you do not need DTO's or VO's. They
are an odious construct used to obviate the
shortcomings of remote method calls over anetwork.
I strongly disagree.
They are an obvious and easy model used when the
following characteristics of a system exist.
- Different layers.
- Related data items that are moved throughout the
layers.
- Different usage of the related data items by
different layers.
Yes, I agree. Note the qualification 'if you are not using a distributed architecture'.
None of that has anything to do with remote method
calls over a network. Point of fact the first time I
used them was in a stand alone application with no
network traffic except that needed by the database
driver itself.
Simply create your domain model objects as POJO's
s (plain ole Java objects). Persist and retrieve
your objects via DAO's (data access objects).Your
service layer (facade) will sit on top of thedomain
model, encapsulating method calls into logicalunits
of work.
And how exactly do you move the customer
name/customer address from the DAO to the GUI level?I am assuming the dedicated remoting product the OP specifid, Hessian, will handle moving between the tiers, or at least between the controller/view and the business tier.
- Saish

How to generate report from two tables using DAO design pattern?

Hi,
Iam using struts with DAO pattern for my application. According to DAO design im creating model class for each table in my database with getter,setter methods. i have no problem when im generating report from one table. but if have i have to join two tables whatis the better way for doing that? is it good practise to create a new model contains properties from both the tables?
Please help me
Thanks in Advance
Rajesh

Dear Rajesh,
As per the pattern you are creating equivalent java objects for every database table under consideration in which each db field will become a private attribute and public getter and setter methods.
If you have to display data from one table the above approach is sufficient enough.
But in case your database is normalised ..lets take an example of Bank having Branch and Accounts tables. We dont need to repeat the whole information of the branch for every account in that branch. so we prefer to have a branch id in that table....this approach lot of insertion/deletion/updatation anomlies that may exists with the database...
now lets come back to our topic....we shall create two java objects 1) Branch 2) Account.....
When ever u just need to display simple report u can do it staright forward,,,,,now if u want to display branch information along with the account information....the two objects just created are not sufficient
So i suggest u the following approaches
1) Create an attribute of type Branch in the Accounts Object......
This shall serve the purpose of displaying the Btranch information
2) Create a collection object of type ( Vector or ArrayList) which can have objects of Account in the Branch Object,,,
Now its upto u how shall u fill up the objects with appropriate sql queries.
The method that i mentioned is followed by Oracle Toplink and Hibernate ....which provide Object to relation mapping layers.
Any queries ...revert back to me...
Mahesh

Using DAO without J2EE/EJB

Can I implement the DAO pattern in my 2-tiered application without using J2EE/EJB? My reason for using DAO is simply to insulate database changes from interface/business code and to make interface/business code easier to write.

Sure, go ahead.

How we can limit the number of concurrent calls to a WCF service without use the Singleton pattern or without do the change in BizTalk Configuration file?

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Hi Pawan,
You need to use WCF-Custom adapter and add the ServiceThrottlingBehavior service behavior to a WCF-Custom Locations.
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Follow MSDN-
http://msdn.microsoft.com/en-us/library/ee377035%28BTS.10%29.aspx
http://msdn.microsoft.com/en-us/library/system.servicemodel.description.servicethrottlingbehavior.maxconcurrentcalls.aspx
I hope this helps.
Rachit
If this answers your question please mark it accordingly. If this post is helpful, please vote as helpful by clicking the upward arrow mark next to my reply.

Anyway to use quartz to schedule jobs without EJB

Hai all,
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Use DAO or plain SQL?

I am building a two-tiered enterprise app with Swing client and RDBMS backend. Over the last two weeks I've tried applying the DAO pattern to my design, manullay creating numerous DTO and DAO classes. I'm now starting to wonder if it's really worth the effort.
My system is not complicated enough to justify the use of automated OR mapping tools or CMP. Also, the development staff on my team, including myself, have had no expereience in OR mapping and EJB; all we've done in the past involve simple application that accesses the database directly using SQL. We also feel that using SQL directly is adequate in implementing all the functionalities of our system.
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TIA.

I wouldn't do any application without using DAOs and
DTOs.
Perhaps you are focusing to much on the examples
rather than on the pattern itself. Just because the
examples do it does not mean that you have to do it.
You can do with with just one infrustructure class (to
do the connections, statement, etc) and then the
following....
class MyDTO
public String field1;
public String field2;
class MyDAO
static void create(MyDTO p) {...}
static void update(MyDTO p) {...}
static void delete(MyDTO p) {...}
static MyDTO getById(String id) {...}
static ArrayList getBySomethingElse(String
somethingElse) {...}
}And of course if you don't need one of the above
methods then do not implement it.i have been doing almost everything in dao but i m not so sure why dtos are so essential, if you write your pojo well, dtos seem to be totally not needed; unless of course you are passing them across networks in ejb systems, and even that, theses days xmls are recommended instead. am i right?
and lately i havee started using hibernate which i think is great even for small not complecated projects: it does not complicate things, and further, you can still do things in dao with hibernate, i dont see any conficts there: hibernate, jdo are mostly mapping mechnism, and dao is a design pattern.

How to use (toplink essentials)JPA with EJB 2.1 spec in oc4j 10.1.3.2

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How I use DAO

I built a struts application .It is working well.Now I want use DAOand .How I use?
My struts application :
Get the input form user and store it in file or datadase. Here I want to use DAO.
There 6 files .
They are
1.inputname.jsp ----------->used for getting input from client.inputs are mail id and password.
2.GetNameForm.java --------->It is Bean having setter and getter including 2 methods are like filehandler(),dbConnection()(here only implementations).
dbConnection method just sample i did. From MSAccess database, get Age field and print it in tomcat prompt. Here only i have probs.*What probs that I need to use DAO.
3.GreetingAction.java ------>It is servlet and I call FormBean Method
By ((sample.GetNameForm)form).filehandler();
((sample.GetNameForm)form).dBConnection();
String name=((sample.GetNameForm)form).getName();
String pass=((sample.GetNameForm)form).getPass();
Thus I called that methods.
It is good one or Not.
Note. Both java file under the package name is sample.
4.greeting.jsp--------> It is output file which is used to expose the output that mail id and password what we gave.
5.index.jsp---------->It is global forward used to forward client request to inputname.jsp.(It is not a matter to consider with out this file applkication working well.)
5.struts-config.xml file here only direction controls and mapping items and brief links (we know that).
package sample;
import java.io.*;
import java.sql.*;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.ActionError;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;
public class GetNameForm extends org.apache.struts.action.ActionForm {
private String name="";
private String pass="";
public GetNameForm() {
// TODO: Write constructor body
public void reset(ActionMapping actionMapping, HttpServletRequest request) {
// TODO: Write method body
// throw new UnsupportedOperationException("Method not implemented");
this.name="";
this.pass="";
public ActionErrors validate(ActionMapping actionMapping, HttpServletRequest request) {
// TODO: Write method body
//throw new UnsupportedOperationException("Method not implemented");
ActionErrors errors=new ActionErrors();
if( getName() == null || getName().length() < 1 ) {
errors.add("name",new ActionMessage("error.name.required"));
// actionMapping.findForward("goInput");
if( getPass() == null || getPass().length() < 1 ) {
errors.add("pass",new ActionMessage("error.pass.required"));
// actionMapping.findForward("goInput");
return errors;
public String getName()
return this.name;
public void setName(String name)
this.name=(name==null?"Please Enter The Name":name);
public String getPass()
return this.pass;
public void setPass(String pass)
this.pass=(pass==null?"Please Enter The ID":pass);
public void dBConnection()
Statement st;
Connection con;
ResultSet rs;
try
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
catch(Exception e)
try
con=null;
st=null;
rs=null;
con=DriverManager.getConnection("jdbc:odbc:MSACCESSDSN","","");
st=con.createStatement();
rs=st.executeQuery("Select * from emp ");
while(rs.next())
          int a=rs.getInt("Age");
          System.out.println(a);
catch(Exception e)
public void filehandler() throws IOException
String name=getName();
String pass=getPass();
//Store the Details of User and Password in File
Writer output = null;
try {
//use buffering
File testFile = new File("C:\\gandhi\\mail_det.txt");
BufferedReader input = null;
input = new BufferedReader( new FileReader(testFile) );
StringBuffer Contents=new StringBuffer();
String line=null;
while (( line = input.readLine()) != null)
{System.out.println("From the file value=" +line);
      java.util.StringTokenizer st = new java.util.StringTokenizer(line,"@");
      System.out.println("The file contains data:"+Contents.append(line+"\n"));
     /* System.out.println(st.nextToken("@"));
      while (st.hasMoreTokens()) {
            if( st.equals("name") ){
            name="";
            pass="";
String str=Contents.toString();
System.out.println("The file Contains"+str);
output = new BufferedWriter( new FileWriter(testFile) );
output.write(str+"\n"+name+"\t"+"........."+pass);
finally {
//flush and close both "output" and its underlying FileWriter
if (output != null)
output.close();
This is my Bean How I use DAO replace of dBConnection()
method.
1.What is important of DAO pls explain me with small codings.
2.How I use DAO in this coding?
[Note: I use Exadel StrutsStudio.]
Anyone have idea pls guide me.

Well in a DAO pattern you usually have one DAO class for each table in the database so there is for instance one PersonDAO and one ItemDAO which have their respective create, read, update and delete methods. Each DAO also hides its implementation through an interface defining the DAO methods, furthermore there's a DAO factory determining what class to load at runtime. My advice is to start out simple and not too abstract, try looking at the following example - it involves EJBs but explains the pattern.
http://www.informit.com/guides/printerfriendly.asp?g=java&seqNum=137&rl=1
Also keep in mind that implementing the DAO pattern using frameworks such as Spring simplifies the process, as illustrated here
http://www.java2s.com/Code/Java/Hibernate/SpringDaoDemo.htm
I hope that helps.

How can i view and apply new custom patterns without going to preset manager? i had this facility but have now lost it

how can i view and apply new custom patterns without going to preset manager? i had this facility but have now lost it. i design patterns but am fairly new to photoshop. i used to be able to click on the drop down menu in patterns in the 'fill' box but cannot now do this. have i inadvertently clicked on something to turn this facility off? i now have to go to 'preset manager' and manually move my new design to the first box and click 'done' so that i can use it.

Which version of photoshop are you using?
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RE: design patterns involving EJBs and JDO

Is the idea that you specify in some config file (xml?) the methods of
your session bean, whether its stateful or stateless, the default bean
transaction semantics, etc, then say "go" and it generates the home and
remote interfaces and the skeletal session bean class?
-----Original Message-----
From: Eric Lindauer [mailto:[email protected]]
Sent: Monday, June 25, 2001 8:26 AM
To: JDO-ListServ
Subject: Re: design patterns involving EJBs and JDO
I don't think it's publicly available yet, I used to work there and was
helping out a little with testing. I'll tell you in advance, it really
works well. Much like the JDO implementation, the process of turning
things into SesisonBeans is very transparent to the developer. I guess
TT is going to make it available in another week or two, as time
permits.
----- Original Message -----
From: Matthew <mailto:[email protected]> Adams
To: '[email protected]' <mailto:'[email protected]'>
Sent: Monday, June 25, 2001 11:18 AM
Subject: RE: design patterns involving EJBs and JDO
IMHO, JDO replaces entity beans, but you'll have to decide for yourself.
My recommendation would be to use session beans exclusively.
Where do you get TechTrader's "SessionBean Creator"? What are its
features? How do you use it?
-----Original Message-----
From: Eric Lindauer [mailto:[email protected]]
Sent: Monday, June 25, 2001 8:12 AM
To: JDO-ListServ
Subject: design patterns involving EJBs and JDO
Hi,
I was just wondering, if you are using JDO for persistence, does it
matter whether you wrap your objects with proxy EntityBeans or
SessionBeans? I am currently demoing TechTrader's SessionBean creator,
which makes means that for me creating SessionBeans is much easier than
creating EntityBeans. I am currently using stateful SessionBeans to
wrap the JDO objects, simply dropping them when the bean is passivated
and refinding them ( they'll already be in the cache ) when the bean is
activated.
My main advantage in doing it this way is SessionBeans are so much
easier to create. Do you see any problems looming, or any other
advantages to this decision?
Thanks in advance.
Eric

I don't think it's publicly available yet, I used to work there and was
helping out a little with testing. I'll tell you in advance, it really
works well. Much like the JDO implementation, the process of turning
things into SesisonBeans is very transparent to the developer. I guess
TT is going to make it available in another week or two, as time
permits.
----- Original Message -----_
From: Matthew <mailto:[email protected]> Adams_
To: '[email protected]' <mailto:'[email protected]'>
Sent: Monday, June 25, 2001 11:18 AM
Subject: RE: design patterns involving EJBs and JDO
IMHO, JDO replaces entity beans, but you'll have to decide for yourself.
My recommendation would be to use session beans exclusively.
Where do you get TechTrader's "SessionBean Creator"? What are its
features? How do you use it?
-----Original Message-----
From: Eric Lindauer [mailto:[email protected]]
Sent: Monday, June 25, 2001 8:12 AM
To: JDO-ListServ
Subject: design patterns involving EJBs and JDO
Hi,
I was just wondering, if you are using JDO for persistence, does it
matter whether you wrap your objects with proxy EntityBeans or
SessionBeans? I am currently demoing TechTrader's SessionBean creator,
which makes means that for me creating SessionBeans is much easier than
creating EntityBeans. I am currently using stateful SessionBeans to
wrap the JDO objects, simply dropping them when the bean is passivated
and refinding them ( they'll already be in the cache ) when the bean is
activated._
My main advantage in doing it this way is SessionBeans are so much
easier to create. Do you see any problems looming, or any other
advantages to this decision?
Thanks in advance.
Eric_

Is outside-in without EJB's possible?

Is it possible to create a web service from a wsdl (outside-in approach) without EJB's involved. in CE7.1
Regards
ABS

Yes, you can but manually. There is no such easy tool as for EJBs in NetWever Developer Studio(NWDS).
Using the the NWDS you can generate automaticaly Outside-In web service sceletons but only with EJB endpoints.
Maybe you have already read that page:
http://help.sap.com/saphelp_nwce10/helpdata/en/46/7f2fef88190ad3e10000000a11466f/content.htm
But if you need a servlet-based web service and you want to start from the WSDL, you can do it manually by creating a pure java class in web project and than adding the annotations with values corresponding to the one from the WSDL. In this case you will need some more knowlage in web services area.
I hope that explainations help you.
Regards,
Yulie.

Webservice, DAO/Bean Pattern - Help

All,
I'm stuck on this one - any help would be much apperciated.
I'm trying to expose a CFC which uses a DAO/Bean pattern and
am receiving the following error.
Could not perform web service invocation "getQuote".
Here is the fault returned when invoking the web service
operation:
AxisFault
faultCode: {
http://schemas.xmlsoap.org/soap/envelope/}Server.userException
faultSubcode:
faultString: coldfusion.xml.rpc.CFCInvocationException:
[coldfusion.runtime.UndefinedElementException : Element
QUOTEDAO is undefined in a Java object of type class
[Ljava.lang.String; referenced as ]
Here are my files to give you an idea of what I am working
with.
/webservices/application.cfm
/webservices/quote/quote.cfc (bean)
/webservices/quote/quoteDAO.cfc (my data access object, has
crud methods)
/webservices/quote/quoteService.cfc (service layer, i
generate my wsdl from this)
I have unit tested the CFC's by running a test.cfm file
within the /webservices directory which calls all methods. Works
fine. Additionally, the WSDL generates fine.
The problem is when I invoke the service, here is how I am
invoking it.
<cfinvoke
webservice="
http://localhost/apps/webservices/quote/quoteService.cfc?wsdl"
method="getQuote"
returnvariable="Quote">
<cfinvokeargument name="Quote_ID" value="200"/>
</cfinvoke>
It's important to note that within my application.cfm I am
setting up my quoteDAO and quoteGateway objects within my variables
scope. I am then setting my quoteService in my application scope,
like so:
<cfset variables.quoteDAO =
createObject("component","apps.webservices.quote.quoteDAO").init(variables.dsn)
/>
<cfset variables.quoteGateway =
createObject("component","apps.webservices.quote.quoteGateway").init(variables.dsn)
/>
<cfset application.quoteService =
createObject("component","apps.webservices.quote.quoteService").init(variables.quoteDAO,
variables.quoteGateway) />
I'm not sure what exactly the error I am receiving is, but
part of me cringes thinking it might have to do with pathing.
Any advice?

Simon,
Thanks for your reply - I modified the code to manually setup
those objects in my init like so.
<cfset variables.dsn = "mydsn" />
<cfset variables.quoteDAO =
createObject("component","apps.webservices.quote.quoteDAO").init(variables.dsn)
/>
<cfset variables.quoteGateway =
createObject("component","apps.webservices.quote.quoteGateway").init(variables.dsn)
/>
It solved that initial error but now I am getting:
Could not perform web service invocation "getQuote".
Here is the fault returned when invoking the web service
operation:
AxisFault
faultCode: {
http://schemas.xmlsoap.org/soap/envelope/}Server.userException
faultSubcode:
faultString: org.xml.sax.SAXParseException: Premature end of
file.
faultActor:
faultNode:
Any ideas?

Using DAO ,TO Pattern without EJB

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