jboss7搭载EJB3之简单会话BEAN与依赖注入jboss数据源

     记录学习的脚步 以备不时之需


主要涉及到有状态会话Bean与无状态会话Bean ，本地接口与远程接口，依赖注入EJB服务与数据源

  理论方面知识简单提一下吧 毕竟我也说的不是特别精辟

   会话Bean一般用于处理业务层操作，有状态Bean与无状态Bean的区别在于是否记录用户的状态信息  ，有状态Bean记录用户的状态信息，采用(写回(不使用时，将Bean的状态写入硬盘)-激活(需要使用时,从硬盘中恢复其状态信息)机制进行控制)，而无状态Bean采用实力池方式控制，类似于数据库连接池

   本地接口与远程接口的区别在于，想要使用本地接口，本地接口与想要使用的业务类代码必须处于一个JVM中，例如部署在一个jboss容器中，本地接口的出现是为了减少远程接口的网络开销、协议解析开销之类的，总之就是加快速度

   依赖注入--都很熟悉了 不解释了

好吧 用一个HelloWorld展现吧  

  从一个无状态HelloWorld类开始吧

package com.undergrowth.hello.impl;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.annotation.Resource;
import javax.ejb.EJB;
import javax.ejb.Local;
import javax.ejb.Remote;
import javax.ejb.Stateless;
import javax.sql.DataSource;

import com.undergrowth.hello.HelloWorldLocal;
import com.undergrowth.hello.HelloWorldRemote;
import com.undergrowth.hello.Other;



/**
 * Session Bean implementation class HelloWorld
 */
@Stateless
@Remote(HelloWorldRemote.class)
@Local({HelloWorldLocal.class})
public class HelloWorld implements HelloWorldRemote,HelloWorldLocal {

	//依赖注入其他EJB服务
	@EJB(beanName="OtherBean") Other other;
	//注入数据源
	@Resource(mappedName="java:/myDataSource") DataSource dataSource;
	/**
     * Default constructor. 
     */
    public HelloWorld() {
        
    }

    /**
     * EJB测试方法
     */
	@Override
	public String sayHello(String what) {
		// TODO Auto-generated method stub
		//通过数据源 获取信息
		String name=connDb(Integer.valueOf(what));
		return "你好，"+what+",我是EJB HELLO WORLD！！"+"
"+other.sayOther(what)+"
"+"我知道你叫"+name;
	}
	
	/**
	 * 本该单独分开写的
	 * 简单处理 就在这写了
	 * @param id
	 * @return
	 */
	private String connDb(int id)
	{
		String str=null;
		Connection conn = null;
        try {
            conn = dataSource.getConnection();
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT st.name from student st WHERE st.id="+id);
            if (rs.next())  str = rs.getString(1);  
            rs.close();
            stmt.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            try {
                if(null!=conn && !conn.isClosed()) conn.close();
            } catch (SQLException e) {
             	e.printStackTrace();
            }
        }
        
        return str;
	}
}

看到他有两个实现接口，一个本地，一个远程

远程接口

package com.undergrowth.hello;

import javax.ejb.Local;
import javax.ejb.Remote;

/**
 * 远程接口
 * HelloWorld Remote interface
 */

public interface HelloWorldRemote {
     public String sayHello(String what);
}
本地接口

package com.undergrowth.hello;

/**
 * 本地接口
 * @author Administrator
 *
 */
public interface HelloWorldLocal {
	public String sayHello(String what);
}


哦 还有一个依赖注入的EJB服务 使用@EJB注解

Other接口

package com.undergrowth.hello;

/**
 * 测试接口
 * @author Administrator
 *
 */
public interface Other {

	public  String sayOther(String what);
}

有状态的Bean 

package com.undergrowth.hello.impl;

import javax.ejb.Stateless;

import com.undergrowth.hello.Other;

/**
 * 测试@EJB 依赖注入 使用其他EJB服务
 * Other不写Remote或者Local的话 默认为本地接口
 * @author Administrator
 *
 */

@Stateless
public class OtherBean implements Other {

	@Override
	public String sayOther(String what) {
		// TODO Auto-generated method stub
		return what+",我是other";
	}

}

好吧  到目前为止 准备了三个接口 一个远程 两个本地  

还有两个会话Bean，一个有状态  ，一个没有状态

哦 对了  还有使用了@Resource 注入了jboss数据源 得去配置一下

在 

jbossjboss-as-7.1.1.Finalstandaloneconfiguration
下的standalone.xml中 在

 <subsystem xmlns="urn:jboss:domain:datasources:1.0">
            <datasources>
元素下添加数据源  修改后如下

<datasources>
                <datasource jndi-name="java:jboss/datasources/ExampleDS" pool-name="ExampleDS" enabled="true" use-java-context="true">
                    <connection-url>jdbc:h2:mem:test;DB_CLOSE_DELAY=-1</connection-url>
                    <driver>h2</driver>
                    <security>
                        <user-name>sa</user-name>
                        <password>sa</password>
                    </security>
                </datasource>
                <datasource jta="true" jndi-name="java:/myDataSource" pool-name="OraclesqlDS" enabled="true" use-java-context="true" use-ccm="true">
                    <connection-url>jdbc:oracle:thin:@localhost:1521:orcl</connection-url>
                    <driver>oracle</driver>
                    <transaction-isolation>TRANSACTION_READ_COMMITTED</transaction-isolation>
                    <pool>
                        <min-pool-size>10</min-pool-size>
                        <max-pool-size>100</max-pool-size>
                        <prefill>true</prefill>
                        <use-strict-min>false</use-strict-min>
                        <flush-strategy>FailingConnectionOnly</flush-strategy>
                    </pool>
                    <security>
                        <user-name>u1</user-name>
                        <password>u1</password>
                    </security>
                </datasource>
                <drivers>
                    <driver name="h2" module="com.h2database.h2">
                        <xa-datasource-class>org.h2.jdbcx.JdbcDataSource</xa-datasource-class>
                    </driver>
                    <driver name="oracle" module="com.oracle.ojdbc6">
                        <xa-datasource-class>oracle.jdbc.xa.client.OracleXADataSource</xa-datasource-class>
                    </driver>
                </drivers>
            </datasources>

因为jboss7的模块化管理     详情可参考  http://vase.iteye.com/blog/1299425

哦  现在剩下的就是将上面的会话Bean打包 发布到JBOSs中  好的  来个ant的build.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- ================================================ -->
<!-- Sample buildfile for jar components -->
<!-- -->
<!-- ================================================ -->
<project name="HelloWorld"  basedir=".">
    <!-- 定义属性 -->
    <property name="src.dir" value="${basedir}src" />
    <property environment="env"  />
    <property name="jboss.home" value="${env.JBOSS_HOME}"/>
    <property name="jboss.server.home" value="standalone"  />
    <property name="dep" value="deployments"  />
    <property name="build.dir" value="${basedir}uild"  />

    <path id="build.classpath">
    	<fileset dir="${basedir}lib">
    		<include name="*.jar" />
    	</fileset>
    	<pathelement location="${build.dir}" />
    </path>

	<!-- - - - - - - - - - - - - - -->
	<!-- target: init -->
	<!-- - - - - - - - - - - - - - -->
	<target name="init">
		<delete dir="${build.dir}"></delete>
		<mkdir dir="${build.dir}"></mkdir>
	</target>

	<!-- ========================= -->
	<!-- target: compile -->
	<!-- ========================= -->
	<target name="compile" depends="init"
		description="--> compile  this component" >

		<javac srcdir="${src.dir}" destdir="${build.dir}" includes="com/**">
			<classpath refid="build.classpath" />
		</javac>
	</target>
	
	<!-- 打包 -->
	<target name="ejbjar" depends="compile" description="打包ejb">
	   <jar jarfile="${basedir}${ant.project.name}.jar">
	   	<fileset dir="${build.dir}">
	   		<include name="**/*.class"></include>
	   	</fileset>
	   	<metainf dir="${src.dir}META-INF"></metainf>
	   </jar>
	</target>

    <!-- 部署 -->
    <target name="delopy" depends="ejbjar" description="部署ejb">
    	<copy file="${basedir}${ant.project.name}.jar"  todir="${jboss.home}${jboss.server.home}${dep}" />
    </target>
    
    <!-- 卸载ejb -->
    <target name="undeploy" description="卸载ejb">
      <delete file="${jboss.home}${jboss.server.home}${dep}${ant.project.name}.jar"></delete>
    </target>
    
	<!-- 打包接口 -->
	<target name="package_inter" depends="compile" description="打包接口">
		<jar jarfile="${basedir}${ant.project.name}Interface.jar">
			   	<fileset dir="${build.dir}">
			   		<exclude name="**/impl/*.class"></exclude>
			   	</fileset>
			   </jar>
	</target>
	
	

</project>

运行ant的deploy 之后 在jboss看到部署信息  

23:52:03,775 INFO  [org.jboss.as.ejb3.deployment.processors.EjbJndiBindingsDeploymentUnitProcessor] (MSC service thread 1-2) JNDI bindings for session bean named OtherBean in deployment unit deployment "HelloWorld.jar" are as follows:

	java:global/HelloWorld/OtherBean!com.undergrowth.hello.Other
	java:app/HelloWorld/OtherBean!com.undergrowth.hello.Other
	java:module/OtherBean!com.undergrowth.hello.Other
	java:global/HelloWorld/OtherBean
	java:app/HelloWorld/OtherBean
	java:module/OtherBean
23:52:03,792 INFO  [org.jboss.as.ejb3.deployment.processors.EjbJndiBindingsDeploymentUnitProcessor] (MSC service thread 1-2) JNDI bindings for session bean named HelloWorld in deployment unit deployment "HelloWorld.jar" are as follows:

	java:global/HelloWorld/HelloWorld!com.undergrowth.hello.HelloWorldRemote
	java:app/HelloWorld/HelloWorld!com.undergrowth.hello.HelloWorldRemote
	java:module/HelloWorld!com.undergrowth.hello.HelloWorldRemote
	java:jboss/exported/HelloWorld/HelloWorld!com.undergrowth.hello.HelloWorldRemote
	java:global/HelloWorld/HelloWorld!com.undergrowth.hello.HelloWorldLocal
	java:app/HelloWorld/HelloWorld!com.undergrowth.hello.HelloWorldLocal
	java:module/HelloWorld!com.undergrowth.hello.HelloWorldLocal


看到HelloWorld既有远程接口又有本地接口  而Other只有本地接口


好了 服务已经在JBOSS的JNDI中了 现在使用客户端进行调用

运行 ant 的 package_inter  打包接口

将打包好的接口 拷贝到 客户端测试项目  HelloWorldWeb 中 在index.jsp中 加入一段代码

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ page import="javax.naming.*,com.undergrowth.hello.*,com.undergrowth.ejb3.client.*" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.jsp' starting page</title>
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->
  </head>
  
  <body>
    <%
    try {
    //本地接口的使用  需要本地接口与EJB应用在一个JVM里面  本地接口才能找到对应部署的EJB应用
			HelloWorldLocal helloWorld=HelloWorldClient.lookupRemoteHelloWorldBean();
			out.println(helloWorld.sayHello("1"));;
		} catch (NamingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
		
     %>
  </body>
</html>


这里调用本地接口 因为测试客户端与服务在一个JBOSS中

JBOSS7的查找JNDI的方法 与之前的版本稍微不一样  如下

public static HelloWorldLocal lookupRemoteHelloWorldBean() throws NamingException {
	        final Hashtable jndiProperties = new Hashtable();
	        jndiProperties.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");
	        final Context context = new InitialContext(jndiProperties);
	        // The app name is the application name of the deployed EJBs. This is typically the ear name
	        // without the .ear suffix. However, the application name could be overridden in the application.xml of the
	        // EJB deployment on the server.
	        // Since we haven't deployed the application as a .ear, the app name for us will be an empty string
	        final String appName = "";
	        // This is the module name of the deployed EJBs on the server. This is typically the jar name of the
	        // EJB deployment, without the .jar suffix, but can be overridden via the ejb-jar.xml
	        // In this example, we have deployed the EJBs in a jboss-as-ejb-remote-app.jar, so the module name is
	        // jboss-as-ejb-remote-app
	        final String moduleName = "HelloWorld";
	        // AS7 allows each deployment to have an (optional) distinct name. We haven't specified a distinct name for
	        // our EJB deployment, so this is an empty string
	        final String distinctName = "";
	        // The EJB name which by default is the simple class name of the bean implementation class
	        final String beanName = "HelloWorld";
	        // the remote view fully qualified class name
	       // final String viewClassName = HelloWorldRemote.class.getName();
	        final String viewClassName = HelloWorldLocal.class.getName();
	        // let's do the lookup
	        return (HelloWorldLocal) context.lookup("ejb:" + appName + "/" + moduleName + "/" + distinctName + "/" + beanName + "!" + viewClassName);
	        
	 }

哦 还有一个 jboss客户端访问jboss服务器的参数文件 文件名为：jboss-ejb-client.properties   放在src目录下即可

endpoint.name=client-endpoint  
remote.connectionprovider.create.options.org.xnio.Options.SSL_ENABLED=false  
   
remote.connections=default  
   
remote.connection.default.host= localhost
remote.connection.default.port = 4447
remote.connection.default.connect.options.org.xnio.Options.SASL_POLICY_NOANONYMOUS=false  
  
remote.connection.default.username=qq     
remote.connection.default.password=q


 参考文档  ：jboss官方参考手册   https://docs.jboss.org/author/display/AS71/EJB+invocations+from+a+remote+client+using+JNDI


发布测试客户端 访问index.jsp  输出如下

你好，1,我是EJB HELLO WORLD！！ 1,我是other 我知道你叫Eason

即可看到 这里获取JBOSS的JNDI树中发布的服务获取到会话Bean  并转给本地接口 本地接口 进行调用相应的服务 完成功能


对于JBOSS  真的要赞一下 很好用


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原文地址：https://www.cnblogs.com/liangxinzhi/p/4275554.html