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:
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" />
解释:
name="jdbc/mysql" //连接名,jndi中使用。具在JSP中用调用,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
DB Connection
jdbc/mysql
javax.sql.DataSource
Container
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+"/";
%>
My JSP 'MyJsp.jsp' starting page
select id, username, password from user
Results
Foo ${row.username}
Bar ${row.password}
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.
*/
public void destroy()
{
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet.
*
* 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.
*
* 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("");
out.println("");
out.println("
A Servlet");
out.println(" ");
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(" ");
out.println("");
out.flush();
out.close();
}
/**
* Initialization of the servlet.
*
* @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
DB Connection
jdbc/mysql
javax.sql.DataSource
Container
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