心有猛虎，细嗅蔷薇: WLS

2009年3月23日星期一

WLS_061：FastSwap特性

运行开发环境：WebLogic Server 12c开发版（12.1.1.1.0） + OEPE 12c（12.1.1.1.0）

FastSwap特性可以动态装载修改后的Java类而无需重新发布应用，显然这能够大大提升开发效率。

1. 创建EAR Application Project：FastSwapApp
（1）

（2）

2. 创建Dynamic Web Project：FastSwapWeb
（1）

（2）选择Add Project to an EAR

（3）index.jsp代码

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"

pageEncoding="ISO-8859-1"%>

<%@ page import="sessionbean.AccountBean" %>

AccountBean bean;

if(session.getAttribute("bean") == null){

bean = new AccountBean();

session.setAttribute("bean",bean);

}else{

bean = (AccountBean)session.getAttribute("bean");

session.setAttribute("balance",bean.getBalance());

}

bean.deposit(100);

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

<body>

Current Balance: <%= bean.getBalance() %>

</body>

</html>

3. 创建EJB Project：EJBProject

（1）选择Add Project to an EAR

（2）选择Add Project to an EAR

（3）EJB代码

package sessionbean;

import static javax.ejb.TransactionAttributeType.*;

import javax.ejb.Stateful;

import javax.ejb.TransactionAttribute;

import javax.ejb.Remote;

import javax.ejb.EJB;

import javax.annotation.PreDestroy;

import javax.interceptor.Interceptors;

import javax.interceptor.ExcludeClassInterceptors;

import javax.interceptor.InvocationContext;

/**

* Bean file that implements the Account business interface. Uses the following

* EJB annotations: - @Stateful: specifies that this is a stateful session EJB - @TransactionAttribute

* - specifies that this EJB never runs in a transaction - @Remote - specifies

* the Remote interface for this EJB - @EJB - specifies a dependency on the

* ServiceBean stateless session ejb - @Interceptors - Specifies that the bean

* file is associated with an Interceptor class; by default all business methods

* invoke the method in the interceptor class annotated with @AroundInvoke. - @ExcludeClassInterceptors

* - Specifies that the interceptor methods defined for the bean class should

* NOT fire for the annotated method. - @PreDestroy - Specifies lifecycle method

* that is invoked when the bean is about to be destoryed by EJB container.

@Stateful

@TransactionAttribute(NEVER)

@Remote({ sessionbean.Account.class })

@Interceptors({ sessionbean.AuditInterceptor.class })

public class AccountBean implements Account {

private int balance = 0;

public void deposit(int amount) {

balance += amount;

System.out.println("deposited: " + amount + " balance: " + balance);

}

public void withdraw(int amount) {

balance -= amount;

System.out.println("withdrew: " + amount + " balance: " + balance);

}

public int getBalance() {

int bogus;

return balance;

}

@ExcludeClassInterceptors

public void sayHelloFromAccountBean() {

}

@PreDestroy

public void preDestroy() {

System.out.println("Invoking method: preDestroy()");

}

4. 修改FastSwapWeb Project的Deployment Assembly
（1）右键FastSwap项目，选择属性，选择Deployment Assembly

（2）点击Add，选择 Project

（3）选择EJB Project和EJBProjectClient

（4）添加完成后，EJBProject.jar和EJBClient.jar添加到WEB-INF/lib目录下。

5. 右键index.jsp，选择Run As，Run on Server
（1）显示Balance值。

（2）刷新页面，会以100递增Balance值。
（3）修改AccountBean.java，修改方法getBalance：return balance + 1;
（4）刷新页面，发现仍以100递增Balance值，也就是没有使用修改后的Java类。

（5）选择Server Tab，Publish应用。