web项目调用Ejb3.0组件学习

最新推荐文章于 2023-01-29 15:44:04 发布

liang_zai

最新推荐文章于 2023-01-29 15:44:04 发布

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文章标签： ejb web import application myeclipse servlet

本文链接：https://blog.youkuaiyun.com/liang_zai/article/details/1750582

本文详细介绍了如何在web项目中调用Ejb3.0组件，包括创建Ejb3.0项目，编写业务接口和无状态会话bean，创建web项目并实现servlet，配置web.xml，以及打包和发布步骤。通过实例展示了ejb3.0在web应用中的使用。

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web项目调用Ejb3.0组件

采用的开发工具为
JbossIDE+MyEclipse+JBoss4.04

一,首先建立一个ejb3.0项目EJB1+WEB

业务接口：

import javax.ejb.Remote;

@Remote
public interface Caculator {

              public int add(int x,int y);

              public int substact(int x,int y);
          }

一个无状态会话bean：

import javax.ejb.Stateless;
import cn.com.liang.Caculator;

public @Stateless class CaculatorBean implements Caculator {

public int add(int x, int y) {

return x+y;
}

public int substact(int x, int y) {
return x-y;
}

}

打包测试成功calculator.jar

二：新建一个web项目EjbWeb

建一个index.jsp页面

   <body>
    <form name="f1" action="servlet/CaculatorServlet" method="post">
    <table>
      <tr>
       <td>number1:<input type="text" name="n1"/></td>
      </tr>
      <tr>
       <td>number2:<input type="text" name="n2"/></td>
      </tr>
      <tr>
       <td><input type="submit" name="Submit" value="add"/><input type="submit" name="Submit" value="substract"/></td>
      </tr>
    </table>
    </form>

</body>

再建一个servlet

import java.io.IOException;
import java.io.PrintWriter;

import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class CaculatorServlet extends HttpServlet {

private static final long serialVersionUID = 488093000861007932L;

private Caculator caculator;

public Caculator getCaculator() {
return caculator;
}

public void setCaculator(Caculator caculator) {
this.caculator = caculator;
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {

  String submit=request.getParameter("Submit");
  int num1=Integer.parseInt(request.getParameter("n1"));
  int num2=Integer.parseInt(request.getParameter("n2"));

  response.setContentType("text/html");
  PrintWriter out = response.getWriter();
  out.println("<!DOCTYPE HTML PUBLIC /"-//W3C//DTD HTML 4.01 Transitional//EN/">");
  out.println("<HTML>");
  out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
  out.println(" <BODY>");
  int result=0;
  if(submit.equals("add")){
   result=caculator.add(num1, num2);
  }else{
   result=caculator.substact(num1,num2);
  }
  out.println(num1+" "+submit+" "+num2+ "= "+result);
  out.println(" </BODY>");
  out.println("</HTML>");
  out.flush();
  out.close();
}

public void init() throws ServletException {
  try {
   InitialContext context=new InitialContext();
   Caculator caculator=(Caculator)context.lookup("mytest/CaculatorBean/remote");
   setCaculator(caculator);
  } catch (NamingException e) {
   e.printStackTrace();
  }
}

}

web.xml中配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>Calculator</servlet-name>
    <servlet-class>cn.com.liang.CaculatorServlet</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>Calculator</servlet-name>
<url-pattern>/servlet/CaculatorServlet</url-pattern>
</servlet-mapping>

</web-app>

由于要用到ejb中接口Caculator ，所以需导入calculator.jar包

将web项目打包为ejbWeb.war。

三，新将一个META-INF文件夹，然后在里面建一个application.xml文件

其内容为

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE application PUBLIC
"-//Sun Microsystems,lnc//DTD j2EE Application 1.3//EN"
"http://java.sun.com/dtd/application_1_3.dtd">
<application>
<display-name>zhouliang's test</display-name>
<module>
  <web>
   <web-uri>ejbWeb.war</web-uri>
   <context-root>/calWeb</context-root>
  </web>
</module>
<module>
  <ejb>calculator.jar</ejb>
</module>
</application>