用spring的beans配置mysql数据库

  今天很兴奋，因为我用spring的beans配置mysql数据库，竟然能用了。下面我用自己写的小项目说一下自己是怎么配置的。
   先说下准备工作，需要下个spring包有：spring-framework-3.1.1.RELEASE-with-docs.zip
   mysql数据库的驱动包：mysql-connector-java-5.1.18.zip
   用mvc模式写本项目：
   配置beans.xml

  

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
        
	<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">  
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />  
        <property name="url" value="jdbc:mysql://localhost:3306/databaseName" />  
        <property name="username" value="root" />  
        <property name="password" value="1234"/>  
    </bean>  

	<bean id="dbHome" class="com.DBHome">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
</beans>

     用一个servlet初始化这个beans，然后用单例模式控制使整个项目用一个bean工厂：
    
    

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.*;
import org.springframework.core.io.*;


public class InitServlet extends HttpServlet {

	public static Resource res = null;
	public static BeanFactory factory = null;
	public InitServlet() {
		super();
	}
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	@SuppressWarnings("deprecation")
	public void init() throws ServletException {
		if(res==null)
			res = new ClassPathResource("/com/beans.xml");
		if(factory==null)
			factory = new XmlBeanFactory(res);	    
	}

}

   
    下面就是mvc模式中的m了，这是我随便写的一个测试类：
    
    

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

import org.springframework.jdbc.datasource.DriverManagerDataSource;


public class DBHome {
	public DriverManagerDataSource database = null;
	public DBHome() {
	}
	public DBHome(DriverManagerDataSource database) {
System.out.println("++++++++++++");
		this.setDataSource(database); 
	}
	public void setDataSource(DriverManagerDataSource database){ //注意这个必须要写这个set方法，这个方法起名是有要求的：set+在beans里面database映射到DBHome里面的名字(首字母要变大写)，也就是setDataSource。这样写，beans会自动找到这个方法，然后给DriverManagerDataSource database赋值。
		this.database = database; 
	}
	public void test(){
		Connection conn=null;
		 try {
			conn =database.getConnection();
			Statement s =conn.createStatement();
			ResultSet res =s.executeQuery("select * from userTable");
			while(res.next()){
				System.out.println(res.getString(2));
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

   然后是mvc中的c了，他要用到DBHome类，应该从beans里面取，该怎么取呢？看下面：

   

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;



public class UserServlet extends HttpServlet {

	public DBHome home = (DBHome)InitServlet.factory.getBean("dbHome");//从beans里面取生成的对象。
	public UserServlet() {
		super();
	}

	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

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

		this.doPost(request, response);
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		home.test();
	}

}

   输出结果：xiaoming
             xiaohong
   当然没写v的部分，在这简单的写了一下spring怎么通过beans配置数据库，通过beans怎么实例化配置在beans里面的类的对象。