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<title>Coding and compiling the test client</title><link rel="stylesheet" href="styles.css" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/styles.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets Vimages/callouts/"><link rel="home" href="index.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/index.html" title="JBoss 3.0 Documentation"><link rel="up" href="ch01.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/ch01.html" title="Chapter 1. First steps"><link rel="previous" href="ch01s14.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/ch01s14.html" title="Packaging and deploying the bean"><link rel="next" href="ch01s16.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/ch01s16.html" title="Conclusion"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><table border="0" cellpadding="0" cellspacing="0" height="65"><tr height="65"><td rowspan="2"><img src="jboss.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/jboss.gif" border="0"></td><td rowspan="2" background="gbar.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/gbar.gif" width="100%" align="right" valign="top"><a href="index.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/index.html"><img src="doc.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/doc.gif" border="0"></a><a href="ch01.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/ch01.html"><img src="toc.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/toc.gif" border="0"></a><a href="ch01s14.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/ch01s14.html"><img src="prev.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/prev.gif" border="0"></a><a href="ch01s16.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/ch01s16.html"><img src="next.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/next.gif" border="0"></a></td></tr><tr></tr></table><div class="section"><a name="d0e376"></a><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="d0e376"></a>Coding and compiling the test client</h2></div></div><p>An EJB on its own is no use; we will need at least a simple client to
use its services. A user of EJBs may be another EJB, an ordinary JavaBean, a
JSP page, an applet, or a stand-alone application. In this example, for
simplicity, we will code a simple application. This application will create an
object of class Interest, and execute its one method.</p><p>On deployment of the bean as performed in the previous step, the
server has bound the EJB home interface under the JNDI name of interest/Interest
and exported the home interface so that it can be invoked via RMI. What we are
going to cover here is the way you lookup a the home interface using JNDI from a
client and invoke methods on it. The example client code is listed in the following figure:</p><div class="figure"><p><a name="d0e383"></a><b>Figure 1.8. Test client, file name InterestClient.java</b></p><pre class="programlisting">package org.jboss.docs.interest;
import javax.naming.InitialContext;
import javax.rmi.PortableRemoteObject;
import org.jboss.docs.interest.Interest;
import org.jboss.docs.interest.InterestHome;
/** This simple application tests the 'Interest' Enterprise JavaBean which is
implemented in the package 'org.jboss.docs.interest'. For this to work, the
Bean must be deployed on an EJB server.
*/
class InterestClient
{
/** This method does all the work. It creates an instance of the Interest EJB on
the EJB server, and calls its `calculateCompoundInterest()' method, then prints
the result of the calculation.
*/
public static void main(String[] args)
{
// Enclosing the whole process in a single `try' block is not an ideal way
// to do exception handling, but I don't want to clutter the program up
// with catch blocks
try
{
// Get a naming context
InitialContext jndiContext = new InitialContext();
System.out.println("Got context");
// Get a reference to the Interest Bean
Object ref = jndiContext.lookup("interest/Interest");
System.out.println("Got reference");
// Get a reference from this to the Bean's Home interface
InterestHome home = (InterestHome)
PortableRemoteObject.narrow(ref, InterestHome.class);
// Create an Interest object from the Home interface
Interest interest = home.create();
// call the calculateCompoundInterest() method to do the calculation
System.out.println("Interest on 1000 units, at 10% per period, compounded over 2 periods is:");
System.out.println(interest.calculateCompoundInterest(1000, 0.10, 2));
}
catch(Exception e)
{
System.out.println(e.toString());
}
}
}</pre></div><p>Please note that the client lookup up the InterestHome interface under the JNDI name "interest/Interest".
Your bean's home interface has been bound to this name if you supplied a proper jboss.xml file. If not,
the JNDI name will be "Interest". Connecting to the JBoss JNDI implementation entails creating an
InitialContext object with the correct jndi.properties in the client classpath. In the source, all that is
required is:<pre class="programlisting">// Get a naming context
InitialContext jndiContext = new InitialContext();
System.out.println("Got context");</pre>
</p><p>The jndi.properties file we have to use is located in the examples/resources/jndi.properties of the
documentation examples distribution. Its contents are:<pre class="programlisting">java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory
java.naming.provider.url=jnp://localhost:1099
java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces</pre>This specifies the InitialContextFactory, provider url, and the packages of object factories
specific to the JBoss JNDI provider. The provider url can be abbreviated to simply "localhost"
or the hostname on which JBoss is running when using the default port of 1099.</p><p>The comments in the program should describe how it works; one point that
requires mention is that the recommended way to get a reference to the home
interface on the server is like this: </p><p>
<pre class="programlisting">InterestHome home = (InterestHome)
PortableRemoteObject.narrow (ref, InterestHome.class);</pre>which ensures compatibility with different RMI protocols (e.g., RMI/IIOP). The 'narrow'
method ensures that the 'ref' object can be converted to an object
of class 'InterestHome'.</p><p>The test client doesn't need to be in the same package as the EJB
classes, and in practice it probably won't be. So it needs to import the EJB
classes using their fully-qualified class name as illustrated.</p><p>To compile and run the InterestClient execute the following ant command:</p><p>
<div class="literallayout"><br>
<tt>bash-2.04$ ant intro-interest-client<br>
Buildfile: build.xml<br>
<br>
validate:<br>
<br>
fail_if_not_valid:<br>
<br>
init:<br>
[echo] Using JBoss directory=/tmp/JBoss-2.2.2<br>
[echo] Using base classpath=/tmp/JBoss-2.2.2/client/ejb.jar:/tmp/JBoss-2.2.2/client/jaas.jar:/tmp/JBoss-2.2.2/client/jbosssx-client.jar:/tmp/JBoss-2.2.2/client/jboss-client.jar:/tmp/JBoss-2.2.2/client/jnp-client.jar:/tmp/tomcat/lib/servlet.jar<br>
[echo] Using Source directory=/tmp/examples<br>
[echo] Using Build directory=/tmp/examples/build-examples<br>
<br>
intro-interest-client:<br>
<br>
compile:<br>
<br>
interest-client:<br>
[echo] Using client classpath: /tmp/JBoss-2.2.2/client/ejb.jar:/tmp/JBoss-2.2.2/client/jaas.jar:/tmp/JBoss-2.2.2/client/jbosssx-client.jar:/tmp/JBoss-2.2.2/client/jboss-client.jar:/tmp/JBoss-2.2.2/client/jnp-client.jar:/tmp/tomcat/lib/servlet.jar:/tmp/examples/build-examples/interest/classes:/tmp/examples/resources<br>
[java] Got context<br>
[java] Got reference<br>
[java] Interest on 1000 units, at 10% per period, compounded over 2 periods is:<br>
[java] 210.00000000000023<br>
<br>
BUILD SUCCESSFUL<br>
<br>
Total time: 2 seconds</tt><br>
</div>
</p><p>The output is what you should see if all goes well. This shows that the classpath used to execute the client
included a number of jars located in the JBoss client directory as well as the directory containing the compiled example
classes and the directory containing the jndi.properties file. These JBoss client jars contain the standard EJB and
JNDI interfaces as well as the JBoss specific container code. The various jars are:<div class="itemizedlist"><ul><li><p><a name="d0e420"></a>ejb.jar : the standard javax.ejb.* EJB 1.1 interfaces and classes.</p></li><li><p><a name="d0e423"></a>jaas.jar : the Java Authentication and Authorization Service security classes.</p></li><li><p><a name="d0e426"></a>jbosssx-client.jar : JBossSX security extension client classes.</p></li><li><p><a name="d0e429"></a>jboss-client.jar : the JBoss EJB container proxy and stub client classes.</p></li><li><p><a name="d0e432"></a>jnp-client.jar : the JBoss JNDI provider client classes.</p></li></ul></div>
</p><p>There should be output from the Interest EJB on the server console as well. This is generated
to show that the bean has executed on the server, not the client. Look for something
like this in the server log or console:</p><p>
<tt>[Interest] Someone called `calculateCompoundInterest!'</tt>
</p><p>Well, that's it. We covered coding, compiling and deploying an EJB,
and coding and running a simple test client. </p></div><table border="0" cellpadding="0" cellspacing="0" height="65"><tr height="65"><td rowspan="2"><img src="gbar.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/gbar.gif" width="432" height="79"></td><td rowspan="2" background="gbar.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/gbar.gif" width="100%" align="right" valign="top"><a href="index.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/index.html"><img src="doc.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/doc.gif" border="0"></a><a href="ch01.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/ch01.html"><img src="toc.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/toc.gif" border="0"></a><a href="ch01s14.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/ch01s14.html"><img src="prev.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/prev.gif" border="0"></a><a href="ch01s16.html" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/ch01s16.html"><img src="next.gif" tppabs="http://www.huihoo.org/jboss/online_manual/3.0/next.gif" border="0"></a></td></tr><tr></tr></table></body></html>⌨️ 快捷键说明
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