简述jdbc，并且spring整合jdbc

首先需要写好我们经常使用的crud方法，也称为jdbc模板。在日常的开发中我们只要调用这些已经写好的jdbc模板方法，就可以很好的加快编码效率。如下：

//使用JDBC模板实现增删改查
public class UserDaoImpl extends JdbcDaoSupport implements UserDao {
	@Override
	public void save(User u) {
		String sql = "insert into t_user values(null,?) ";
		super.getJdbcTemplate().update(sql, u.getName());
	}
	@Override
	public void delete(Integer id) {
		String sql = "delete from t_user where id = ? ";
		super.getJdbcTemplate().update(sql,id);
	}
	@Override
	public void update(User u) {
		String sql = "update  t_user set name = ? where id=? ";
		super.getJdbcTemplate().update(sql, u.getName(),u.getId());
	}
	@Override
	public User getById(Integer id) {
		String sql = "select * from t_user where id = ? ";
		return super.getJdbcTemplate().queryForObject(sql,new RowMapper<User>(){
			@Override
			public User mapRow(ResultSet rs, int arg1) throws SQLException {
				User u = new User();
				u.setId(rs.getInt("id"));
				u.setName(rs.getString("name"));
				return u;
			}}, id);
		
	}
	@Override
	public int getTotalCount() {
		String sql = "select count(*) from t_user  ";
		Integer count = super.getJdbcTemplate().queryForObject(sql, Integer.class);
		return count;
	}

	@Override
	public List<User> getAll() {
		String sql = "select * from t_user  ";
		List<User> list = super.getJdbcTemplate().query(sql, new RowMapper<User>(){
			@Override
			public User mapRow(ResultSet rs, int arg1) throws SQLException {
				User u = new User();
				u.setId(rs.getInt("id"));
				u.setName(rs.getString("name"));
				return u;
			}});
		return list;
	}


}

接下来就是配置数据库和连接池之类的，原生的写法比较繁琐，如下：

@Test
	public void fun1() throws Exception{
		
		//0 准备连接池
		ComboPooledDataSource dataSource = new ComboPooledDataSource();
		dataSource.setDriverClass("com.mysql.jdbc.Driver");
		dataSource.setJdbcUrl("jdbc:mysql:///hibernate_32");
		dataSource.setUser("root");
		dataSource.setPassword("1234");
		//1 创建JDBC模板对象
		JdbcTemplate jt = new JdbcTemplate();
		jt.setDataSource(dataSource);
		//2 书写sql,并执行
		String sql = "insert into t_user values(null,'rose') ";
		jt.update(sql);
		
	}

但是我们有了spring容器之后，可以把这些对象交给spring来管理。如下：

jdbc.jdbcUrl=jdbc:mysql:///hibernate_32
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.user=root
jdbc.password=1234

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd ">

<!-- 指定spring读取db.properties配置 -->
<context:property-placeholder location="classpath:db.properties"  />

<!-- 1.将连接池放入spring容器 -->
<bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" >
	<property name="jdbcUrl" value="${jdbc.jdbcUrl}" ></property>
	<property name="driverClass" value="${jdbc.driverClass}" ></property>
	<property name="user" value="${jdbc.user}" ></property>
	<property name="password" value="${jdbc.password}" ></property>
</bean>


<!-- 2.将JDBCTemplate放入spring容器 -->
<bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate" >
	<property name="dataSource" ref="dataSource" ></property>
</bean>

<!-- 3.将UserDao放入spring容器 -->
<bean name="userDao" class="cn.itcast.a_jdbctemplate.UserDaoImpl" >
	<!-- <property name="jt" ref="jdbcTemplate" ></property> -->
	<property name="dataSource" ref="dataSource" ></property>
</bean>
	

</beans>

简述jdbc，并且spring整合jdbc

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