Spring對JDBC的支持訪問數據庫

基於Spring框架訪問數據庫，需要配置對數據源的引用，建立對數據庫訪問的連接。

1、Spring+jdbc與DataSource的整合應用（基於jdbc的數據源配置注入）

例題：利用Spring框架，並基於JDBC數據源注入方式，實現在數據庫表中插入和查詢數據。

(1)dataSource.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"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

	<!-- 配置DataSource數據源 -->
	<bean id="dataSources"
		class="org.springframework.jdbc.datasource.DriverManagerDataSource">
		<property name="username" value="root"></property>
		<property name="password" value="root"></property>
		<property name="url"
			value="jdbc:mysql://localhost:3306/spring?serverTimezone=GMT%2B8"></property>
		<property name="driverClassName"
			value="com.mysql.cj.jdbc.Driver"></property>
	</bean>
	<!-- 配置工具類的Bean -->
	<bean id="dbUtils" class="com.spring.datasource.DbUtil">
		<property name="dataSource" ref="dataSources"></property> <!-- 引用所配置的數據源 -->
	</bean>

	<!-- 配置DAO的Bean -->
	<bean id="userDao" class="com.spring.datasource.UserDAO">
		<property name="dbUtil" ref="dbUtils"></property> <!-- 引用所配置的工具Bean -->
	</bean>
</beans>

(2) DbUtil工具類
package com.spring.datasource;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;

public class DbUtil {

	private DataSource dataSource;

	public DataSource getDataSource() {
		return dataSource;
	}

	public void setDataSource(DataSource dataSource) {
		this.dataSource = dataSource;
	}

	// 從數據源對象dataSource獲取數據連接對象的方法
	public Connection getConnection() throws SQLException {
		Connection conn = null;
		conn = dataSource.getConnection();
		return conn;
	}

	public void close(Connection conn, PreparedStatement pstmt, ResultSet rs) {
		if (rs != null)
			try {
				rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		if (pstmt != null)
			try {
				pstmt.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		if (conn != null)
			try {
				conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
	}
}