WebLogic的研究之三－－開發、部署EJB（1） (轉)[@more@]

LOGIC的研究之三－－開發、部署（1）

作者：XYZ

這裡不會討論EJB的概念，只討論如何編寫一個簡單EJB，部署EJB，Weblogic與JBuilder的整合，本文先把介紹僅用文字編輯器編寫一個最簡單的EJB所需要的一切，以讓大家一覽EJB的概貌，然後才介紹如何把Weblogic與JBuilder整合起來，使用JBuilder開發Weblogic的EJB，我相信這樣會得到很好的學習效果，因為這是我學習的路徑，當然我會把我遇到的問題告訴大家，以免大家走彎路。

下面是一個最簡單的EJB所需要的程式碼及說明，手工製作EJB的JAR包比較麻煩，在下，我仿照例子製作了一個 build.cmd 批處理

weblogic-ejb-jar.xml

HelloWorlean

100

hello.HelloWorld

ejb-jar.xml

/A>Beans 1.1//EN' ''>

HelloWorldBean
hello.HelloWorldHome
hello.HelloWorld
hello.HelloWorldBean
Stateless
Container

HelloWorldBean
*

Required

package hello;

import java..*;
import javax.ejb.*;

public class HelloWorldBean implements SessionBean {
private SessionContext sessionContext;
public void ejbCreate() {
}
public void ejbRemove() {
}
public void ejbActivate() {
}
public void ejbPassivate() {
}
public void setSessionContext(SessionContext context) {
sessionContext = context;
}
public String getHelloWorld(){
return "Hello World!";
}
}

HelloWorld.java
package hello;

import java.rmi.*;
import javax.ejb.*;

public interface HelloWorld extends EJB {
public java.lang.String getHelloWorld() throws RemoteException;
}

HelloWorldHome.java
package hello;

import java.rmi.*;
import javax.ejb.*;

public interface HelloWorldHome extends EJBHome {
public HelloWorld create() throws RemoteException, CreateException;
}

HelloWorldBean.java
package hello;
import java.rmi.*;
import javax.ejb.*;

public class HelloWorldBean implements SessionBean {
private SessionContext sessionContext;
public void ejbCreate() {
}
public void ejbRemove() {
}
public void ejbActivate() {
}
public void ejbPassivate() {
}
public void setSessionContext(SessionContext context) {
sessionContext = context;
}
public String getHelloWorld(){
return "Hello World!";
}
}

HelloWorldBeanClient1.java
package hello;

import javax.naming.*;
import javax.rmi.PortableRemoteObject;

public class HelloWorldBeanClient1 {
private static final String ERROR_NULL_REMOTE = "Remote interface reference is null. It must be created by calling one of the Home interface methods first.";
private static final int MAX_OUTPUT_LINE_LENGTH = 50;
private boolean logging = true;
private HelloWorldHome helloWorldHome = null;
private HelloWorld helloWorld = null;

/**Construct the EJB test client*/
public HelloWorldBeanClient1() {
long startTime = 0;
if (logging) {
log("Initializing bean access.");
startTime = System.currentTimeMillis();
}

try {
//get naming context
Context ctx = new InitialContext();

//look up jndi name
Object ref = ctx.lookup("HelloWorld");

//cast to Home interface
helloWorldHome = (HelloWorldHome) PortableRemoteObject.narrow(ref, HelloWorldHome.class);
if (logging) {
long endTime = System.currentTimeMillis();
log("Succeeded initializing bean access.");
log("Execution time: " + (endTime - startTime) + " ms.");
}

HelloWorld hello=helloWorldHome.create();
String str=hello.getHelloWorld();
System.out.println(str);
}
catch(Exception e) {
if (logging) {
log("Failed initializing bean access.");
}
e.printStackTrace();
}
}

//----------------------------------------------------------------------------
// Methods that use Home interface methods to generate a Remote interface reference
//----------------------------------------------------------------------------

public HelloWorld create() {
long startTime = 0;
if (logging) {
log("Calling create()");
startTime = System.currentTimeMillis();
}
try {
helloWorld = helloWorldHome.create();
if (logging) {
long endTime = System.currentTimeMillis();
log("Succeeded: create()");
log("Execution time: " + (endTime - startTime) + " ms.");
}
}
catch(Exception e) {
if (logging) {
log("Failed: create()");
}
e.printStackTrace();
}

if (logging) {
log("Return value from create(): " + helloWorld + ".");
}
return helloWorld;
}

//----------------------------------------------------------------------------
// Methods that use Remote interface methods to access data through the bean
//----------------------------------------------------------------------------

public String getHelloWorld() {
String returnValue = "";
if (helloWorld == null) {
System.out.println("Error in getHelloWorld(): " + ERROR_NULL_REMOTE);
return returnValue;
}
long startTime = 0;
if (logging) {
log("Calling getHelloWorld()");
startTime = System.currentTimeMillis();
}

try {
returnValue = helloWorld.getHelloWorld();
if (logging) {
long endTime = System.currentTimeMillis();
log("Succeeded: getHelloWorld()");
log("Execution time: " + (endTime - startTime) + " ms.");
}
}
catch(Exception e) {
if (logging) {
log("Failed: getHelloWorld()");
}
e.printStackTrace();
}

if (logging) {
log("Return value from getHelloWorld(): " + returnValue + ".");
}
return returnValue;
}

//----------------------------------------------------------------------------
// Utility Methods
//----------------------------------------------------------------------------

private void log(String message) {
if (message.length() > MAX_OUTPUT_LINE_LENGTH) {
System.out.println("-- " + message.substring(0, MAX_OUTPUT_LINE_LENGTH) + " ...");
}
else {
System.out.println("-- " + message);
}
}
/**Main method*/

public static void main(String[] args) {
HelloWorldBeanClient1 client = new HelloWorldBeanClient1();
// Use the client object to call one of the Home interface wrappers
// above, to create a Remote interface reference to the bean.
// If the return value is of the Remote interface type, you can use it
// to access the remote interface methods. You can also just use the
// client object to call the Remote interface wrappers.
}
}

build.cmd

if "" == "%JAVA_HOME%" set JAVA_HOME=java
if "" == "%WL_HOME%" set WL_HOME=weblogic
set MYSERVER=%WL_HOME%myserver
set MYCLASSPATH=%JAVA_HOME%libclasses.zip;%WL_HOME%classes;%WL_HOME%libweblogicaux.jar;%MYSERVER%clientclasses

@REM Create the build directory, and copy the deployment descriptors into it
mkdir build buildMETA-INF
copy *.xml buildMETA-INF

@REM Compile ejb classes into the build directory (jar preparation)
javac -d build -classpath %MYCLASSPATH% HelloWorld.java HelloWorldHome.java HelloWorldBean.java

@REM Make a standard ejb jar file, including XML deployment descriptors
cd build
jar cv0f std_ejb_HelloWorld.jar META-INF hello
cd ..

@REM Run ejbc to create the deployable jar file
java -classpath %MYCLASSPATH% -Dweblogic.home=%WL_HOME% weblogic.ejbc -compiler javac buildstd_ejb_HelloWorld.jar %MYSERVER%ejb_Hello.jar

@REM Compile ejb interfaces & client app into the clientclasses directory
javac -d %MYSERVER%clientclasses -classpath %MYCLASSPATH% HelloWorld.java HelloWorldHome.java HelloWorldBeanClient1.java

WebLogic的研究之三－－開發、部署EJB（1） (轉)

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