最近在学习JNDI，今天整出来一个demo，拿出来大家分享下。
先上一个项目结构的截图：
1、配置JNDI数据源
首先，修改一下tomcat的配置文件conf/context.xml
在Context属性中加入
<Resource name="jndi-web"
type="javax.sql.DataSource"
driverClassName="oracle.jdbc.OracleDriver"
url="jdbc:oracle:thin:@localhost:1521:orcl"
username="scott"
password="tigger"
maxIdle="40"
maxWait="4000"
maxActive="250"
removeAbandoned="true"
removeAbandonedTimeout="100"
logAbandoned="true"
factory="org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory"
/>
其次，项目中的web.xml中加入
<resource-ref>
<description>DB Connection</description>
<res-ref-name>jndi-web</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
最后，就是在spring的配置文件applicationContext.xml中加入
<bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName">
<value>java:comp/env/jndi-web</value>
</property>
</bean>
到这里，JNDI的配置就算是结束了。注意：上面3个配置文件中都用到了“jndi-web”的名称，请保持一致性。
2、SpringMVC的配置
首先，在项目中的web.xml文件中加入
<servlet>
<servlet-name>test</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet><servlet-mapping>
<servlet-name>test</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
其次，加入controller代码<HelloController.java>：
package com.blanddrift.controller;import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;import com.blanddrift.util.DataBaseUtil;
public class HelloController implements Controller {
@Override
public ModelAndView handleRequest(HttpServletRequest req,
HttpServletResponse resp) throws Exception {
Connection conn = DataBaseUtil.getConn();
List<Map<String, String>> list = new ArrayList<Map<String,String>>();
try {
Statement stt = conn.createStatement();
ResultSet rs = stt.executeQuery("select * from emp");
while(rs.next()) {
Map<String, String> map = new HashMap<String, String>();
map.put("empno", rs.getString(1));
map.put("ename", rs.getString(2));
map.put("job", rs.getString(3));
map.put("mgr", rs.getString(4));
map.put("hiredate", rs.getString(5));
map.put("sal", rs.getString(6));
map.put("comm", rs.getString(7));
map.put("deptno", rs.getString(8));
list.add(map);
}
req.setAttribute("emp", list);
} catch (Exception e) {
e.printStackTrace();
} finally {
DataBaseUtil.closeConn(conn);
}
req.setAttribute("hello", "Welcome to spring!!!");
return new ModelAndView("welcome");
}}
上面用到一个的DataBaseUtil的代码如下<DataBaseUtil.java>：
package com.blanddrift.util;import java.sql.Connection;
import java.sql.SQLException;import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;public class DataBaseUtil {
private static DataSource ds;
static {
try {
Context ctx = new InitialContext();
ds = (DataSource) ctx.lookup("java:comp/env/jndi-web");
} catch (NamingException e) {
e.printStackTrace();
}
}private DataBaseUtil(){}
public synchronized static Connection getConn(){
try {
return ds.getConnection() != null ? ds.getConnection() : null;
} catch (SQLException e) {
e.printStackTrace();
}return null;
}public static void closeConn(Connection conn) {
try{
if(conn != null) {
conn.close();
conn = null;
}
} catch (Exception e) {
e.printStackTrace();
}
}}
最后，在WEB-INF下新建test-servlet.xml的配置文件（文件名称为web.xml中的<servlet-name>属性
+ “-servlet.xml”），文件内容如下：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans><!--缺省映射处理器，不需要明确声明，但声明后就非常清楚使用的是哪个映射处理器 -->
<bean id="beanNameUrlMapping"
class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping">
</bean><!-- 这里的name属性有两个职责，既定义Bean的名字，也定义需要这个控制器处理的URL样式 -->
<bean name="/hello.do" class="com.blanddrift.controller.HelloController">
</bean><bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean></beans>
根据test-servlet.xml的配置文件可以知道我们需要编写的jsp文件，即/WEB-INF/jsp/welcome.jsp，下面提供welcome.jsp的代码：
<%@page import="java.util.Map"%>
<%@page import="java.util.List"%>
<%@ page contentType="text/html; charset=UTF-8"%>
<%@ page isELIgnored="false" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Hello World!</title>
</head>
<body>
<h2>
This is a note which come from Java !!!
</h2>
<h3>
${hello }
</h3>
<table border="1" cellpadding="0" cellspacing="0">
<tr>
<td>empno</td>
<td>ename</td>
<td>job</td>
<td>mgr</td>
<td>hiredate</td>
<td>sal</td>
<td>comm</td>
<td>deptno</td>
</tr>
<%
List<Map<String, String>> list = (List<Map<String, String>>)request.getAttribute("emp");
for(int i = 0; i < list.size(); i++) {
Map<String, String> map = list.get(i);
%>
<tr>
<td><%=map.get("empno")%></td>
<td><%=map.get("ename")%></td>
<td><%=map.get("job")%></td>
<td><%=map.get("mgr")%></td>
<td><%=map.get("hiredate")%></td>
<td><%=map.get("sal")%></td>
<td><%=map.get("comm")%></td>
<td><%=map.get("deptno")%></td>
</tr>
<%
}
%>
</table>
</body>
</html>
3、部署工程，启动刚才修改过context.xml文件的tomcat，访问http://localhost:8080/jndi-web/hello.do，就会得到下面的页面：
项目的war包：jndi-web.zip
springMVC-JNDI