初识spring（十一）

spring之对jdbc的支持

spring可以通过c3p0对数据库支持。

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Dept.java

package cn.itcast.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;    }}

UserDao.java

package cn.itcast.h_jdbc;import java.sql.ResultSet;import java.sql.SQLException;import java.util.List;import java.util.Map;import javax.sql.DataSource;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.jdbc.core.RowCallbackHandler;import org.springframework.jdbc.core.RowMapper;public class UserDao {    private JdbcTemplate jdbcTemplate;    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {        this.jdbcTemplate = jdbcTemplate;    }    public void save() {        String sql = "insert into t_dept(deptName) values('test');";        jdbcTemplate.update(sql);    }    public Dept findById(int id) {        String sql = "select * from t_dept where deptId=?";        List<Dept> list = jdbcTemplate.query(sql,new MyResult(), id);        return (list!=null && list.size()>0) ? list.get(0) : null;    }    public List<Dept> getAll() {        String sql = "select * from t_dept";        List<Dept> list = jdbcTemplate.query(sql, new MyResult());        return list;    }    class MyResult implements RowMapper<Dept>{        // 如何封装一行记录        @Override        public Dept mapRow(ResultSet rs, int index) throws SQLException {            Dept dept = new Dept();            dept.setDeptId(rs.getInt("deptId"));            dept.setDeptName(rs.getString("deptName"));            return dept;        }    }}

UserDao1.java
这是一个传统的jdbc

package cn.itcast.h_jdbc;import java.sql.Connection;import java.sql.DriverManager;import java.sql.Statement;public class UserDao01 {    /*     *  保存方法     *  需求优化的地方：     *      1. 连接管理     *      2. jdbc操作重复代码封装     */    public void save() {        try {            String sql = "insert into t_dept(deptName) values('test');";            Connection con = null;            Statement stmt = null;            Class.forName("com.mysql.jdbc.Driver");            // 连接对象            con = DriverManager.getConnection("jdbc:mysql:///hib_demo", "root", "root");            // 执行命令对象            stmt =  con.createStatement();            // 执行            stmt.execute(sql);            // 关闭            stmt.close();            con.close();        } catch (Exception e) {            e.printStackTrace();        }    }}

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UserDao2.java
使用datasource来做数据库操作。

package cn.itcast.h_jdbc;import java.sql.Connection;import java.sql.DriverManager;import java.sql.Statement;import javax.sql.DataSource;public class UserDao02 {    // IOC容器注入    private DataSource dataSource;    public void setDataSource(DataSource dataSource) {        this.dataSource = dataSource;    }    public void save() {        try {            String sql = "insert into t_dept(deptName) values('test');";            Connection con = null;            Statement stmt = null;            // 连接对象            con = dataSource.getConnection();            // 执行命令对象            stmt =  con.createStatement();            // 执行            stmt.execute(sql);            // 关闭            stmt.close();            con.close();        } catch (Exception e) {            e.printStackTrace();        }    }}

bean.xml

<?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">    <!-- 1. 数据源对象: C3P0连接池 -->    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>        <property name="jdbcUrl" value="jdbc:mysql:///hib_demo"></property>        <property name="user" value="root"></property>        <property name="password" value="root"></property>        <property name="initialPoolSize" value="3"></property>        <property name="maxPoolSize" value="10"></property>        <property name="maxStatements" value="100"></property>        <property name="acquireIncrement" value="2"></property>    </bean>    <!-- 2. 创建JdbcTemplate对象 -->    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">        <property name="dataSource" ref="dataSource"></property>    </bean>    <!-- dao 实例 -->    <bean id="userDao" class="cn.itcast.h_jdbc.UserDao">        <property name="jdbcTemplate" ref="jdbcTemplate"></property>    </bean></beans>