chapter6.htm

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to write any descriptors for the data sources as we did with Session and BMP 
beans, as the EJB container is responsible for that.</I></FONT></FONT></P>
<P><IMG height=578 src="chapter6.files/ejbJarFirst.png" width=460 align=left 
border=0 name=Graphic12><BR clear=left><B><FONT face="Nimbus Roman No9 L"><FONT 
color=#000000>As shown in the code snippet above from the ejb-jar.xml file, all 
abstract methods are generated as persistent fields under the tag 
&lt;cmp-field&gt; because of the tag @persistence-field declared at each 
accessor method. Also the primary key class descriptor is 
generated</FONT></FONT></B> <B>under the &lt;primary-key-class&gt; tag and the 
primary key field is generated under the &lt;primarykey-field&gt; because of the 
tag @field-pk declared for the relevant attribute(s)</B>. </P>
<P><B>Descriptors for finder methods are generated along with the query defined 
to fetch the data as shown below</B>. <B>These finder tags are generated by the 
@ejb.finder tag declared at class level. </B></P>
<P><IMG height=484 src="chapter6.files/ejbJarSecond.png" width=630 align=left 
border=0 name=Graphic13><BR clear=left><B>And in the jboss.xml file, the 
following descriptors are generated due to the tag @ejb.bean declared at class 
level, as shown below.</B></P>
<P><IMG height=88 src="chapter6.files/jboss.png" width=322 align=left border=0 
name=Graphic15><BR clear=left><FONT color=#800000><FONT 
face="Nimbus Roman No9 L"><I>Note : @ejb.bean tag has been covered in previous 
chapters.</I></FONT></FONT></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Item Bean 
functionality is complete in and ready for deployment.</B></FONT></FONT></P>
<H3><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Deploy Item Bean 
:</B></FONT></FONT></H3>
<P><B>Go to Lomboz J2EE View &gt; expand node MyStore &gt; expand MyStoreMgr 
&gt; select Jboss 3.2.1 ALL.</B></P>
<P><B>Right click &gt; select Debug Sever on the pop up menu.</B></P>
<P><FONT color=#800000><I>Note : This is to start your server, if you are 
already running your server then skip these steps and go to the next 
one.</I></FONT></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Go to MyStoreMgr node 
in LombozJ2EE view &gt; right click &gt; select Deploy on the pop up menu as 
shown below.</B></FONT></FONT></P>
<P><IMG height=230 src="chapter6.files/LombozJ2EEViewDeployBean.png" width=444 
align=left border=0 name=Graphic19><BR clear=left><BR><BR></P>
<P><FONT color=#800000><I>Note : All these steps have been detailed in previous 
chapters (1 and 3), so, please refer to them.</I></FONT></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Messages in the 
console will indicate whether deployment of your bean has been successful or 
not.</B></FONT></FONT></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Now, lets modify 
StoreAccessBean to invoke methods on ItemBean.</B></FONT></FONT></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Add a field to store 
our Item reference (obtained from JNDI lookup).</B></FONT></FONT></P><PRE style="MARGIN-BOTTOM: 0.2in"><FONT face=Sans><FONT size=3><SPAN style="BACKGROUND: none transparent scroll repeat 0% 0%"><FONT color=#000000>private</FONT></SPAN><FONT color=#7f0055> </FONT><FONT color=#000000>ItemLocalHome</FONT> item<FONT color=#000000>LocalHome</FONT>;</FONT></FONT></PRE>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>In the ejbCreate 
method store this reference in the itemLocalHome variable by invoking the 
getLocalHome static method in the ItemUtil class as shown in this code snippet 
below from StoreAccess Bean.</B></FONT></FONT></P>
<P><IMG height=282 src="chapter6.files/StoreAccessEjbCreate.png" width=448 
align=left border=0 name=Graphic20><BR clear=left><BR><BR></P>
<H3><B>Add a Business Method to StoreAccess :</B></H3>
<P><B>Add another business method to the StoreAccess Bean which will invoke this 
business method on our Item Bean.</B></P>
<P><FONT face="Nimbus Roman No9 L"><B>Now, add a business method with this 
signature:</B></FONT></P>
<P><FONT face="Nimbus Roman No9 L"><B><FONT color=#000000>public ItemData</FONT> 
<FONT color=#000000>getItemData(String itemID)</FONT></B></FONT></P>
<P><FONT face="Nimbus Roman No9 L"><B><FONT color=#000000>.. with Interface type 
as Remote. As managers will log on to MyStore with username, once 
authe</FONT>nticated they will be identified by their userid. They can then 
retrieve their account details from MyStore using that userid. A Manager can 
invoke methods on the Item Bean to examine the inventory of 
MyStore.</B></FONT></P>
<P><FONT color=#800000><FONT face="Nimbus Roman No9 L"><I>Note : Steps to create 
business methods are covered in previous chapters.</I></FONT></FONT></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><FONT size=3><B>Now 
invoke one of Item's finder methods via the reference variable we have created 
in the ejbCreate method.</B></FONT></FONT></FONT></P><PRE style="MARGIN-BOTTOM: 0.2in"><FONT size=3><FONT face=Sans>ItemLocal item  =   itemLocalHome.findByPrimaryKey(itemID)</FONT> </FONT>        </PRE>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><FONT size=3><B>Now 
invoke the business method of Customer on this 
reference.</B></FONT></FONT></FONT></P><PRE style="MARGIN-BOTTOM: 0.2in"><FONT face=Sans><FONT size=3>ItemData myItem = item.getItemData() </FONT></FONT></PRE>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Code snippet for this 
business method is shown below.</B></FONT></FONT></P>
<P><IMG height=356 src="chapter6.files/StoreAccessGetItemData.png" width=500 
align=left border=0 name=Graphic31><BR clear=left><BR><BR></P>
<P><B>Add another business method to StoreAccess Bean.</B></P>
<P><B>Add a business method with this signature:</B></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>public 
java.util.ArrayList getOutOfStockItems()</B></FONT></FONT></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>.. with Interface type 
as Remote. This will return the items which are out of stock in 
MyStore.</B></FONT></FONT></P>
<P style="FONT-STYLE: normal"><FONT color=#000000><FONT 
face="Nimbus Roman No9 L"><FONT size=3><B>Create two variables of type 
Collection and ArrayList respectively, as the finder method for Items returns a 
Collection and this method will return an ArrayList, after populating items 
which are out of stock from the returned 
Collection.</B></FONT></FONT></FONT></P><PRE style="MARGIN-BOTTOM: 0.2in"><FONT face=Sans><FONT size=3>Collection items = null;</FONT></FONT>
<FONT size=3><FONT face=Sans>ArrayListItemsOutOfStock = null;</FONT>  </FONT>      </PRE>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Now invoke one of the 
finder methods of Item on the reference variable we have created in the 
ejbCreate method.</B></FONT></FONT></P><PRE style="MARGIN-BOTTOM: 0.2in"><FONT face=Sans><FONT size=3>items = itemLocalHome.findByOutOfStock()</FONT></FONT></PRE>
<P><B>Now iterate through the collection of out of stock items and add to the 
ArrayList.</B></P><PRE style="MARGIN-BOTTOM: 0.2in"><FONT color=#000000><FONT face=Sans><FONT size=3><B>I</B>temLocal myItemLocal  = (ItemLocal) iterate.next();</FONT></FONT></FONT>
<FONT color=#000000><FONT face=Sans><FONT size=3>itemsOutOfStock.add(myItemLocal.getItemData()); </FONT></FONT></FONT></PRE>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Code snippet for this 
business method is shown below.</B></FONT></FONT></P>
<P><IMG height=392 src="chapter6.files/StoreAccessGetItemOutOfStock.png" 
width=558 align=left border=0 name=Graphic36><BR clear=left><BR><BR></P>
<P><B>Add another business method to StoreAccess Bean.</B></P>
<P><B>Add a business method with this signature:</B></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>public 
java.util.ArrayList getItemBySupplier(String supplierID)</B></FONT></FONT></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>.. with Interface type 
as Remote. This will return the items which are provided to MyStore by a given 
supplier.</B></FONT></FONT></P>
<P style="FONT-STYLE: normal"><FONT color=#000000><FONT 
face="Nimbus Roman No9 L"><FONT size=3><B>Create two variables of type 
Collection and ArrayList respectively as the finder method for Items returns a 
Collection and this method will return ArrayList, after populating items which 
are supplied by a particular supplier from the returned 
Collection.</B></FONT></FONT></FONT></P><PRE style="MARGIN-BOTTOM: 0.2in"><FONT face=Sans><FONT size=3>Collection suppliedItems = null;</FONT></FONT>
<FONT size=3><FONT face=Sans>ArrayList itemsBySupplier = null;</FONT>  </FONT>      </PRE>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Now invoke one of the 
finder methods of Item on the reference variable we have created in the 
ejbCreate method.</B></FONT></FONT></P><PRE style="MARGIN-BOTTOM: 0.2in"><FONT face=Sans><FONT size=3>suppliedItems = itemLocalHome.findBySupplierID(supplierID)</FONT></FONT></PRE>
<P><B>Now iterate through the collection of items for this supplier and add to 
the ArrayList.</B></P><PRE style="MARGIN-BOTTOM: 0.2in"><FONT color=#000000><FONT face=Sans><FONT size=3><B>I</B>temLocal myItemsLocal  = (ItemLocal) iterate.next();</FONT></FONT></FONT>
<FONT color=#000000><FONT face=Sans><FONT size=3>itemsBySupplier.add(myItemsLocal.getItemData()); </FONT></FONT></FONT>
<FONT color=#000000><FONT face="Nimbus Roman No9 L"><FONT size=3><B>Code snippet for this business method is shown below.</B></FONT></FONT></FONT></PRE>
<P><IMG height=396 src="chapter6.files/StoreAccessGetItemBySupplier.png" 
width=538 align=left border=0 name=Graphic37><BR clear=left><BR><BR></P>
<P><FONT color=#000000><FONT face="Nimbus Roman No9 L"><B>Now all the methods in 
StoreAccess Bean for accessing Item's business methods have been added. The only 
remaining bit is the deployment descriptors required for linking/referencing of 
StoreAccess and Item Bean. So we will the add two tags shown 
below.</B></FONT></FONT></P>
<P><IMG height=172 src="chapter6.files/StoreAccessDeploymentDescriptors.png" 
width=446 align=left border=0 name=Graphic38><BR clear=left><BR><BR></P>
<P><B>First add the tag shown below at class level in StoreAccess Bean.</B></P><PRE><FONT color=#3f5fbf><FONT face=Sans><FONT style="FONT-SIZE: 11pt" size=2>@ejb.ejb<FONT color=#7f7f9f>-</FONT>ref ejb<FONT color=#7f7f9f>-</FONT>name="Item"</FONT></FONT></FONT>
<FONT face=Sans><FONT style="FONT-SIZE: 11pt" size=2><FONT color=#3f5fbf>view</FONT><FONT color=#7f7f9f>-</FONT><FONT color=#3f5fbf>type="local"</FONT></FONT></FONT>
<FONT face=Sans><FONT style="FONT-SIZE: 11pt" size=2><FONT color=#3f5fbf>ref</FONT><FONT color=#7f7f9f>-</FONT><FONT color=#3f5fbf>name="ItemLocal"</FONT></FONT></FONT></PRE>
<P><B>This tag will generate deployment descriptors in 'ejb-jar.xml', as 
StoreAccessBean has to know which bean it is referring to, what is its view-type 
and ref-name. This will generate these descriptors as shown below.</B></P>
<P><FONT color=#800000><FONT face="Nimbus Roman No9 L"><I>Note : View type is 
local as both are in the same Java Virtual Machine, otherwise it would be 
Remote. Secondly ref-name is generated as ItemLocalHome, as we are using that 
rather than ItemHome (which was also generated, but is used in the Remote 
case).</I></FONT></FONT></P>
<P><IMG height=576 src="chapter6.files/ejbJarStoreAccess.png" width=466 
align=left border=0 name=Graphic39><BR clear=left><BR><BR></P>
<P><B>Now add a second tag (shown below) at class level in StoreAccess 
Bean.</B></P><PRE><FONT face=Sans><FONT size=3><FONT color=#3f5fbf>@jboss.ejb</FONT><FONT color=#7f7f9f>-</FONT><FONT color=#3f5fbf>ref</FONT><FONT color=#7f7f9f>-</FONT><FONT color=#3f5fbf>jndi</FONT> <FONT color=#3f5fbf>ref</FONT><FONT color=#7f7f9f>-</FONT><FONT color=#3f5fbf>name="ItemLocal"</FONT></FONT></FONT>
<FONT face=Sans><FONT size=3><FONT color=#3f5fbf>jndi</FONT><FONT color=#7f7f9f>-</FONT><FONT color=#3f5fbf>name="ItemLocal"</FONT></FONT></FONT></PRE>
<P>This tag will generate deployment descriptors in 'jboss.xml', as the 
application server has to know what jndi-name the Item bean has been registered 
with. This will generate these descriptors as shown below.</P>
<P><FONT color=#800000><I>Note : Ref-name and jndi-name are used for bean as 
local (in same JVM).</I></FONT></P>
<P><IMG height=344 src="chapter6.files/jbossStoreAccess.png" width=352 
align=left border=0 name=Graphic40><BR clear=left><FONT color=#800000><I>Note : 
We can see in the code snippet above the deployment descriptors generated by tag 
@jboss. For the view type 'local' it generates incorrect deployment descriptors, 
as discussed in the previous chapter. So every time we use this tag we have to 
change the &lt;ejb-ref&gt; to &lt;ejb-local-ref&gt; before deployment. 
<B>Caution here</B>, that you do this change manually when you finally finish 
regenerating your EJB classes, because every time you regenerate your classes, 
'jboss.xml' will be overwritten.</I></FONT></P>
<P><B>Now our Item Bean is complete after these changes, so deploy your bean 
again now, from the Lomboz J2EE View, as per the steps shown above and in 
previous chapters. Messages will appear in the console showing the status of 
deployment.</B></P>
<P><B>Once the bean is deployed successfully, create a test client which will 
invoke the loginUser method on StoreAccess Bean , getCustomerData on Customer 
Bean, getManagerData on Manager Bean and getOutOfStockItems on Item 
Beam.</B></P>
<H3 style="MARGIN-TOP: 0in; MARGIN-BOTTOM: 0in"><BR></H3>
<H3 style="MARGIN-TOP: 0in; MARGIN-BOTTOM: 0in"><B>Create your Test Client 
:</B></H3>
<P style="MARGIN-BOTTOM: 0in"><BR></P>
<P>G<B>o to Project MytStore node &gt; select src node and expand it &gt; select 
au.com.tusc.client package &gt; right click.</B></P>
<P><B>Select New on the pop up menu &gt; select Lomboz EJB Test Client 
Wizard</B>. </P>
<P><B>Select package name au.com.tusc.client, name as SessionCMPClient and 
select Ejb Home as au.com.tusc.session.StoreAccessHome and Ejb Interface as