软件版本myeclispe8.0，自带tomcat6.0.13。
jdbc:mysql-connector-java-5.1.13-bin.jar
第一步：建立工程。
在Myeclipse中file->new->web project。
因为在测试数据源（jsp）时用到了标签库，所以可以在这里选上jsdl支持，当然也可以在工程建好后右键工程文件夹->myeclipse->add JSTL
Libraries…实现同样的功能。
第二步：导入jdbc的jar包。
要直接将mysql-connector-java-3.1.7-bin.jar复制到“工程文件夹/WebRoot/WEB-INF/lib”文件夹下。这时，myeclipse会自动生成一个
Referenced Libraries，不用管。
第三步：建立context.xml文件。
在“工程文件夹/WebRoot/META-INF”下，新建context.xml文件。文件内容如下：
| <?xml version="1.0" encoding="UTF-8"?> <Context debug="5" reloadable="true"> <Resource name="jdbc/mysql" auth="Container" type="javax.sql.DataSource" maxActive="100" maxIdle="30" maxWait="10000" username="root" password="" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost:3306/javatest?autoReconnect=true" /> </Context> |
解释：
name="jdbc/mysql" //连接名，jndi中使用。具在JSP中用<sql:query var="rs" dataSource="jdbc/mysql">调用，servlet用 DataSource ds
= (DataSource)ctx.lookup("java:comp/env/jdbc/mysql");调用。这里是tomcat的格式，不同的服务器可能有所不同。
auth="Container"
type="javax.sql.DataSource"
maxActive="100"
maxIdle="30"
maxWait="10000"
username="root" //mysql的用户名
password="" //mysql的用户密码，我这里是空
driverClassName="com.mysql.jdbc.Driver" //驱动类名，一般确定
url="jdbc:mysql://localhost:3306/javatest?autoReconnect=true" //javatest是mysql中要使用的数据库名
第四步：修改web.xml文件。
在web.xml文件中添加以下内容： //重要一定添加进去
<resource-ref>
<description>DB Connection</description>
<res-ref-name>jdbc/mysql</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
这部分内容一般是确定的。
OK，现在可以测试数据源是否好了。下面是JSP测试文件：
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%@ taglib uri=" http://java.sun.com/jsp/jstl/sql " prefix="sql" %>
<%@ taglib uri=" http://java.sun.com/jsp/jstl/core " prefix="c" %>
<%
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 'MyJsp.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">
-->
<sql:query var="rs" dataSource="jdbc/mysql">
select id, username, password from user
</sql:query>
</head>
<body>
<h2>Results</h2>
<c:forEach var="row" items="${rs.rows}">
Foo ${row.username}<br/>
Bar ${row.password}<br/>
</c:forEach> <br>
</body>
</html>
当然，如果你用servlet测试数据源也是可以的，下面是一个servlet测试例子：
package fx;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.naming.Context;
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;
import javax.sql.DataSource;
public class DsTest extends HttpServlet
{
/**
* Constructor of the object.
*/
public DsTest()
{
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy()
{
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
doPost(request,response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
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>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the POST method");
try
{
Context ctx = new InitialContext();
DataSource ds = (DataSource)ctx.lookup("java:comp/env/jdbc/mysql");
Connection conn = ds.getConnection();
ResultSet rs=conn.createStatement().executeQuery("select * from user");
rs.next();
out.print(rs.getString(2));
} catch (NamingException e) {
e.printStackTrace(out);
System.out.println(e.getMessage());
} catch (SQLException e) {
e.printStackTrace(out);
}
out.println("connection pool connected !!haha");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException
{
// Put your code here
}
}
我的mysql数据库名为javatest，表名为user，有三列"id"，"username"，"password"。servlet运行结果将打印出user表中的第一个用户名。
注意：如果你新建servlet，myeclipse会自动帮你在web.xml中生成相应的mapping，而这部分内容可能“插”进
<resource-ref>
<description>DB Connection</description>
<res-ref-name>jdbc/mysql</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
中，造成错误。注意自己手动调整。 //要看一下，因为我的好像没有这段代码
别外，注意myeclipse中的servlet映射为“服务器ip:端口/工程文件名/servlet/servlet名”。
还有就是最好使用外部自己配置的Tomcat，并将mysql-connector-java-5.1.13-bin.jar包放到Tomcat的lib目录下。
最好不要用MyEclipse自带的Tomcat，因为我的MyEclipse提示org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver'
即Tomcat出现异常，找不到jdbc驱动包
