Spring基礎（四）之整合JDBC模板對象

1.spring提供了一個可以操作數據庫的對象，對象封裝了jdbc技術。

JDBCTemplate：JDBC模板對象。

2.準備工作導包：

3.準備數據庫

我們可以創建一個很簡單的數據庫，進行測試。

 4使用JdbcTemplate對象

package cn.itcast.a_jdbctemplate;

import java.beans.PropertyVetoException;

import org.junit.Test;
import org.springframework.jdbc.core.JdbcTemplate;

import com.mchange.v2.c3p0.ComboPooledDataSource;

//演示jdbc模板
public class Demo {
	@Test
	public void fun1() throws PropertyVetoException{
		//準備連接池
		ComboPooledDataSource dataSource = new ComboPooledDataSource();
		dataSource.setDriverClass("com.mysql.jdbc.Driver");
		dataSource.setJdbcUrl("jdbc:mysql:///springtest?serverTimezone=UTC");
		dataSource.setUser("root");
		dataSource.setPassword("root");
		//創建jdbc模板對象
		JdbcTemplate jt = new JdbcTemplate();
		jt.setDataSource(dataSource);
		//書寫sql,執行
		String sql = "insert into t_user values(null,'ssl')";
		jt.update(sql);
	}
}

這樣就可以對我們的數據庫進行添加數據了。

5.spring整合jdbc-連接池&JDBC模板&Dao配置到spring容器

package cn.itcast.a_jdbctemplate;

public class User {
	private Integer id;
	private String name;
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
	
}

package cn.itcast.a_jdbctemplate;
import java.util.List;
public interface UserDao {
	//增
	void save(User u);
	//刪
	void delete(Integer id);
	//改
	void update(User u);
	//查
	User getByTd(Integer id);
	//查
	int getTotalCoubt(User u);
	//查
	List <User> getAll();
}

 

package cn.itcast.a_jdbctemplate;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
//使用JDBC模板實現增刪改查
public class UserDaoImpl implements UserDao {

	private JdbcTemplate jt;
	
	@Override
	public void save(User u) {
		// TODO Auto-generated method stub
		String sql = "insert into t_user values(null,?)";
		jt.update(sql, u.getName());
	}

	@Override
	public void delete(Integer id) {
		// TODO Auto-generated method stub
		String sql = "delete from t_user where id = ?";
		jt.update(sql, id);
	}

	@Override
	public void update(User u) {
		// TODO Auto-generated method stub
		String sql = "update t_user set name=? where id=?";
		jt.update(sql, u.getName(),u.getId());
	}

	@Override
	public User getByTd(Integer id) {
		String sql = "select * from t_user where id = ?";
		return jt.queryForObject(sql, new RowMapper<User>(){

			@Override
			public User mapRow(ResultSet rs, int arg1) throws SQLException {
				// TODO Auto-generated method stub
				User u = new User();
				u.setId(rs.getInt("id"));
				u.setName(rs.getString("name"));
				return u;
			}}, id);
		// TODO Auto-generated method stub

		
	}

	@Override
	public int getTotalCoubt(User u) {
		String sql = "select count(*) from t_user";
		Integer count =  jt.queryForObject(sql, Integer.class);
		return count;
		
	}

	@Override
	public List<User> getAll() {
		// TODO Auto-generated method stub
		String sql = "select * from t_user";
		List<User> list = jt.query(sql,new RowMapper<User>(){

			@Override
			public User mapRow(ResultSet rs, int arg1) throws SQLException {
				// TODO Auto-generated method stub
				User u = new User();
				u.setId(rs.getInt("id"));
				u.setName(rs.getString("name"));
				return u;
			}});
		return list;
	}

	public JdbcTemplate getJt() {
		return jt;
	}

	public void setJt(JdbcTemplate jt) {
		this.jt = jt;
	}

	
	
}

 

package cn.itcast.a_jdbctemplate;

import java.beans.PropertyVetoException;

import javax.annotation.Resource;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.mchange.v2.c3p0.ComboPooledDataSource;

//演示jdbc模板
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class Demo {
	@Resource(name="userDao")
	private UserDao ud;
	@Test
	public void fun1() throws PropertyVetoException{
		//準備連接池
		ComboPooledDataSource dataSource = new ComboPooledDataSource();
		dataSource.setDriverClass("com.mysql.jdbc.Driver");
		dataSource.setJdbcUrl("jdbc:mysql:///springtest?serverTimezone=UTC");
		dataSource.setUser("root");
		dataSource.setPassword("root");
		//創建jdbc模板對象
		JdbcTemplate jt = new JdbcTemplate();
		jt.setDataSource(dataSource);
		//書寫sql,執行
		String sql = "insert into t_user values(null,'ssl')";
		jt.update(sql);
	}
	
	@Test
	public void fun2() throws PropertyVetoException{
		User u = new User();
		u.setName("tom");
		ud.save(u);
	}
	
}

<?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 ">
<!-- 1將連接池放入到spring容器 -->
<bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
	<property name="jdbcUrl" value="jdbc:mysql:///springtest?serverTimezone=UTC"></property>
	<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
	<property name="user" value="root"></property>
	<property name="password" value="root"></property>
</bean>

<!-- 2將JDBCTemplate對象放入到連接池  -->
<bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
	<property name="dataSource" ref="dataSource"></property>
</bean>
<!-- 3將UserDao放入到spring -->
<bean name="userDao" class="cn.itcast.a_jdbctemplate.UserDaoImpl">
	<property name="jt" ref="jdbcTemplate"></property>
</bean>
</beans>

 6.spring整合jdbc-讀取properties配置

我們看到在我們的代碼中那我們的用戶，密碼，jdbcUrl等都寫死了，如果要改，需要每次該我們的配置文件，很麻煩。可以使用properties來解決。

我們可以是建立一個db.properties文件：

jdbc.jdbcUrl=jdbc:mysql:///springtest?serverTimezone=UTC
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.User=root
jdbc.Password=root

 然後在我們的配置文件中使用就可以了。

<?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 ">
<!-- 1將連接池放入到spring容器 -->
<context:property-placeholder location="classpath:db.properties"/>
<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將JDBCTemplate對象放入到連接池  -->
<bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
	<property name="dataSource" ref="dataSource"></property>
</bean>
<!-- 3將UserDao放入到spring -->
<bean name="userDao" class="cn.itcast.a_jdbctemplate.UserDaoImpl">
	<property name="jt" ref="jdbcTemplate"></property>
</bean>
</beans>