【Spring】spring对jdbc的优化

使用步骤:

先引入jdbc相关jar包

然后在db.properties中配置连接数据库的信息

jdbc.user=rootjdbc.password=rootjdbc.driverClass=com.mysql.jdbc.Driverjdbc.jdbcUrl=jdbc:mysql:///day09jdbc.initPoolSize=5jdbc.maxPoolSize=10jdbc.maxStatements=100jdbc.acquireIncrement=2

接下来创建Dept对象

package cn.qblank.h_jdbc;public class Dept {private int deptId;private String deptName;public int getDeptId() {return deptId;}public void setDeptId(int deptId) {this.deptId = deptId;}public String getDeptName() {return deptName;}public void setDeptName(String deptName) {this.deptName = deptName;}@Overridepublic String toString() {return "Dept [deptId=" + deptId + ", deptName=" + deptName + "]";}}

编写对应的UserDao类

package cn.qblank.h_jdbc;import java.sql.ResultSet;import java.sql.SQLException;import java.util.List;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.jdbc.core.RowMapper;public class UserDao {//加入IOC容器中private JdbcTemplate jdbcTemplate;public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {this.jdbcTemplate = jdbcTemplate;}/** * 添加数据 */public void save(){String sql = "insert into dept(deptName) value('赵六')";jdbcTemplate.update(sql);}/** * 通过id查找数据 * @param id * @return */public Dept findById(int id){String sql = "select * from dept where deptId = ?";List<Dept> list = jdbcTemplate.query(sql, new MyResult(),id);return (list!=null && list.size() >0)?list.get(0):null;}/** * 查询所有 * @return */public List<Dept> findAll(){String sql = "select * from dept";List<Dept> list = jdbcTemplate.query(sql, new MyResult());return list;}//结果集内部类class MyResult implements RowMapper<Dept>{@Overridepublic Dept mapRow(ResultSet rs, int index) throws SQLException {Dept dept = new Dept();dept.setDeptId(rs.getInt("deptId"));dept.setDeptName(rs.getString("deptName"));return dept;}}}

然后配置bean.xml,将对象（userDao和jdbcTemplate）加入IOC容器以及初始化c3p0连接池

<?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:p="http://www.springframework.org/schema/p"    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">        <!-- 导入资源文件 -->        <context:property-placeholder location="classpath:db.properties"/>        <!-- 配置c3p0连接池 -->        <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">        <property name="driverClass" value="${jdbc.driverClass}"></property>        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>        <property name="user" value="${jdbc.user}"></property>        <property name="password" value="${jdbc.password}"></property>        <property name="initialPoolSize" value="${jdbc.initPoolSize}"></property>        <property name="maxPoolSize" value="${jdbc.maxPoolSize}"></property>        <property name="maxStatements" value="${jdbc.maxStatements}"></property>        <property name="acquireIncrement" value="${jdbc.acquireIncrement}"></property>        </bean><!-- 创建jdbcTemplate对象 --><bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"><!-- 加入c3p0配置 --><property name="dataSource" ref="dataSource"></property></bean>                <!-- jdbcTemplate实例 -->        <bean id="userDao" class="cn.qblank.h_jdbc.UserDao">        <property name="jdbcTemplate" ref="jdbcTemplate"></property>        </bean></beans>

接下来我们来测试各个方法

package cn.qblank.h_jdbc;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Test {public static void main(String[] args) {ApplicationContext ac = new ClassPathXmlApplicationContext("cn/qblank/h_jdbc/bean.xml");UserDao userDao = (UserDao) ac.getBean("userDao");userDao.save();System.out.println(userDao.findById(3));System.out.println(userDao.findAll());ac = null;}}

插入的数据在数据库中也能看到了