EJB 3.0 开发指南之定时服务_MySQL
EJB
在EJB2.1的规范中需要实现ejbTimeout方法,当然还有ejbPassivate、ejbRemove等方法。在EJB3.0中,只有你想用它们的时候,你才必须创建它们,否则不必实现。
这个例子主要有5个文件,这个例子的Bean是一个无状态会话Bean:
NewsTimer.java:业务接口。
NewsTimer.java:业务实现类。将来我们开发的EJB也都是这样命名(在接口名上加上Bean)。
Client.java:测试EJB的客户端类。
jndi.properties:jndi属性文件,提供访问jdni的基本配置属性。
Build.xml:ant 配置文件,用以编译、发布、测试、清除EJB。
下面针对每个文件的内容做一个介绍。
NewsTimer.java
package com.kuaff.ejb3.schedule;
import javax.ejb.Remote;
@Remote
public interface NewsTimer
{
public void fiveNews();
}
这个接口定义了fiveNews方法,如果这个方法被调用,5分钟后将往控制台上输出一条新闻。
你不必配置它的JNDI名称,也不必写它的配置文件。在JBOSS实现的EJB3.0中,你不必写任何的EJB部署文件和jboss部署文件。JBOSS默认使用接口的全称作为它的JNDI名。在上面的例子中,它的全称可以通过NewsTimerclass.forName()得到。
NewsTimerBean.java
package com.kuaff.ejb3.schedule;
import java.util.Date;
import javax.ejb.Inject;
import javax.ejb.SessionContext;
import javax.ejb.Stateless;
import javax.ejb.Timer;
@Stateless
public class NewsTimerBean implements NewsTimer
{
private @Inject SessionContext ctx;
public void fiveNews()
{
ctx.getTimerService().createTimer(new Date(new Date().getTime() + 300000), "子虚乌有电视台5分钟新闻栏目:现在过5分钟,又到即时新闻节目的时间了。");
}
public void ejbTimeout(Timer timer)
{
System.out.printf("时间到:%n%s%n" , timer.getInfo());
timer.cancel();
}
}
Client.java
package com.kuaff.ejb3.schedule;
import javax.naming.InitialContext;
import javax.naming.NamingException;
public class Client
{
public static void main(String[] args) throws NamingException
{
InitialContext ctx = new InitialContext();
NewsTimer timer = (NewsTimer) ctx.lookup(NewsTimer.class.getName());
timer.fiveNews();
}
}
这个类用来测试我们发布的计数器EJB。首先通过
ctx = new InitialContext();
得到上下文,然后通过lookup查找NewsTimer,然后启动计时。。
请运行{$JBOSS_HOME}/bin目录下的run.bat: run

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

When deleting or decompressing a folder on your computer, sometimes a prompt dialog box "Error 0x80004005: Unspecified Error" will pop up. How should you solve this situation? There are actually many reasons why the error code 0x80004005 is prompted, but most of them are caused by viruses. We can re-register the dll to solve the problem. Below, the editor will explain to you the experience of handling the 0x80004005 error code. Some users are prompted with error code 0X80004005 when using their computers. The 0x80004005 error is mainly caused by the computer not correctly registering certain dynamic link library files, or by a firewall that does not allow HTTPS connections between the computer and the Internet. So how about

VSCode Setup in Chinese: A Complete Guide In software development, Visual Studio Code (VSCode for short) is a commonly used integrated development environment. For developers who use Chinese, setting VSCode to the Chinese interface can improve work efficiency. This article will provide you with a complete guide, detailing how to set VSCode to a Chinese interface and providing specific code examples. Step 1: Download and install the language pack. After opening VSCode, click on the left

This AI-assisted programming tool has unearthed a large number of useful AI-assisted programming tools in this stage of rapid AI development. AI-assisted programming tools can improve development efficiency, improve code quality, and reduce bug rates. They are important assistants in the modern software development process. Today Dayao will share with you 4 AI-assisted programming tools (and all support C# language). I hope it will be helpful to everyone. https://github.com/YSGStudyHards/DotNetGuide1.GitHubCopilotGitHubCopilot is an AI coding assistant that helps you write code faster and with less effort, so you can focus more on problem solving and collaboration. Git

On March 3, 2022, less than a month after the birth of the world's first AI programmer Devin, the NLP team of Princeton University developed an open source AI programmer SWE-agent. It leverages the GPT-4 model to automatically resolve issues in GitHub repositories. SWE-agent's performance on the SWE-bench test set is similar to Devin, taking an average of 93 seconds and solving 12.29% of the problems. By interacting with a dedicated terminal, SWE-agent can open and search file contents, use automatic syntax checking, edit specific lines, and write and execute tests. (Note: The above content is a slight adjustment of the original content, but the key information in the original text is retained and does not exceed the specified word limit.) SWE-A

Go language development mobile application tutorial As the mobile application market continues to boom, more and more developers are beginning to explore how to use Go language to develop mobile applications. As a simple and efficient programming language, Go language has also shown strong potential in mobile application development. This article will introduce in detail how to use Go language to develop mobile applications, and attach specific code examples to help readers get started quickly and start developing their own mobile applications. 1. Preparation Before starting, we need to prepare the development environment and tools. head

Working with files in the Linux operating system requires the use of various commands and techniques that enable developers to efficiently create and execute files, code, programs, scripts, and other things. In the Linux environment, files with the extension ".a" have great importance as static libraries. These libraries play an important role in software development, allowing developers to efficiently manage and share common functionality across multiple programs. For effective software development in a Linux environment, it is crucial to understand how to create and run ".a" files. This article will introduce how to comprehensively install and configure the Linux ".a" file. Let's explore the definition, purpose, structure, and methods of creating and executing the Linux ".a" file. What is L

The os.Rename function is used in Go language to rename files. The syntax is: funcRename(oldpath,newpathstring)error. This function renames the file specified by oldpath to the file specified by newpath. Examples include simple renaming, moving files to different directories, and ignoring error handling. The Rename function performs an atomic operation and may only update directory entries when the two files are in the same directory. Renames may fail across volumes or while a file is in use.

As a fast and efficient programming language, Go language is widely popular in the field of back-end development. However, few people associate Go language with front-end development. In fact, using Go language for front-end development can not only improve efficiency, but also bring new horizons to developers. This article will explore the possibility of using the Go language for front-end development and provide specific code examples to help readers better understand this area. In traditional front-end development, JavaScript, HTML, and CSS are often used to build user interfaces
