Spring中c3p0連接池的配置 及JdbcTemplate的使用 通過XML配置文件注入各種需要對象的操作 來完成數據庫添加Add（）方法

通過配置文件XML方法的配置

可以使用非常簡練的Service類

UserService類代碼如下：

package com.swift;

public class UserService {
    private UserDao userDao;

    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
    public boolean add() {
        return userDao.add();
    }
}

UserService要調用UserDao中連接數據庫的方法add()，需要一個userDao對象，這個對象通過配置文件XML來注入對象，需要setUserDao()來配合

同樣UserDao類也非常簡練

package com.swift;

import org.springframework.jdbc.core.JdbcTemplate;

public class UserDao {
    private JdbcTemplate jdbcTemplate;
    
    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    public boolean add() {
//        ComboPooledDataSource dataSource=new ComboPooledDataSource();
//        dataSource.setDriverClass("com.mysql.jdbc.Driver");
//        dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/sw_database");
//        dataSource.setUser("root");
//        dataSource.setPassword("root");
    
    String sql="insert into sw_user(username,password) values(?,?)";
    int count=jdbcTemplate.update(sql,"彈痕","戰俠歌"); 
    if(count==1) {
        return true;
    }
    return false;
    }
}

UserDao中要使用JdbcTemplate的對象，這個對象也通過配置文件XML來注入，需要setJdbcTemplate()來配合

而jdbcTemplate對象又需要通過XML在配置中注入dataSource對象

dataSource對象是通過c3p0連接池類得到，需要導入前一篇隨筆提供的jar包支持

XML配置文件代碼：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
         http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    
    <!-- c3p0連接池得到dataSource -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
    <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/sw_database"></property>
    <property name="user" value="root"></property>
    <property name="password" value="root"></property>
    </bean>
    
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
    <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    <bean id="userDao" class="com.swift.UserDao">
    <property name="jdbcTemplate" ref="jdbcTemplate"></property>
    </bean>
    
    <bean id="userService" class="com.swift.UserService">
    <property name="userDao" ref="userDao"></property>
    </bean>
    
</beans>

測試類中只要得到XML配置文件對象就可以搞定所有了

代碼如下：

package com.swift;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

@WebServlet("/test")
public class ServletTest extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    public ServletTest() {
        super();
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        response.getWriter().append("Served at: ").append(request.getContextPath());
        
        //使用JdbcTemplat的queryForObject方法
        ApplicationContext context=new ClassPathXmlApplicationContext("c3p0.xml");
        UserService userService= (UserService) context.getBean("userService");
        if(userService.add()) {
            response.getWriter().append("添加成功！");
        }else {
            response.getWriter().append("添加失敗！");
        }
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

}

瀏覽器中結果：

數據庫中結果：