使用Spring Jdbc (1)

 

文件及其环境要求：

 

 

<?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:aop="http://www.springframework.org/schema/aop"xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd"><!-- 基于数据源的数据管理器适用于jdbc以及iBatis --><!-- 读取配置文件 --><bean id="propertyConfigurer"class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"><property name="location" value="jdbc.properties"></property></bean><bean id="dataSource"class="org.apache.commons.dbcp.BasicDataSource"destroy-method="close"><property name="driverClassName"value="${jdbc.driverClassName}" /><!-- 读取相应的配置文件的值 --><property name="url" value="${jdbc.url}" /><property name="username" value="${jdbc.username}" /><property name="password" value="${jdbc.password}" /></bean><bean id="jdbcTemplate"class="org.springframework.jdbc.core.JdbcTemplate"><property name="dataSource" ref="dataSource" /></bean><bean id="dao" abstract="true"><property name="jdbcTemplate" ref="jdbcTemplate" /></bean><bean id="formDao" parent="dao" class="com.macower.spring.jdbc.FormJdbcDao"/></beans>

package com.macower.spring.jdbc;public class Form {private int userId;private String userName;public Form() {super();}public int getUserId() {return userId;}public void setUserId(int userId) {this.userId = userId;}public String getUserName() {return userName;}public void setUserName(String userName) {this.userName = userName;}}

jdbc。properties

 

jdbc.driverClassName=com.mysql.jdbc.Driverjdbc.url=jdbc:mysql://127.0.0.1:3306/sampledbjdbc.username=rootjdbc.password=root

 

 

package com.macower.spring.jdbc;import java.sql.PreparedStatement;import java.sql.SQLException;import java.sql.Types;import org.springframework.jdbc.core.PreparedStatementSetter;import org.springframework.jdbc.core.support.JdbcDaoSupport;public class FormJdbcDao extends JdbcDaoSupport {public void createTableByJdbcDaoSupport() {String sql = "create table tb_user(user_id int primary key, user_name varchar(60))";// 创建一张表getJdbcTemplate().execute(sql);}public void addForm(final Form form) {// 为了form可以在内部类中使用所以必须加入final的修饰符String sql = "insert into tb_user values(?,?)";// PreparedStatementSetter是一个回调接口，JdbcTemplate使用sql语句创建出PreparedStatement实例后// 将用该回调接口执行绑定的参数getJdbcTemplate().update(sql, new PreparedStatementSetter() {// 通过匿名的内部类回调实例@Overridepublic void setValues(PreparedStatement ps)throws SQLException {ps.setInt(1, form.getUserId());ps.setString(2, form.getUserName());}});}/** * 更新数据形式1： getJdbcTemplate().update(sql, params); * @param form */public void updateForm1(Form form){String sql = "insert into tb_user values(?,?)";Object [] params = new Object[]{form.getUserId(),form.getUserName()};getJdbcTemplate().update(sql, params);}/** * 更新数据形式2： getJdbcTemplate().update(sql, params,Types[]); * @param form */public void updateForm2(Form form){String sql = "insert into tb_user values(?,?)";Object [] params = new Object[]{form.getUserId(),form.getUserName()};getJdbcTemplate().update(sql, params,new int[]{Types.INTEGER,Types.VARCHAR});}public void addForm2(final Form form){final String sql = "insert into tb_user values(?,?)";//PreparedStatementCreator是一个回调的接口，负责创建PreparedStatement实例getJdbcTemplate().update(new PreparedStatementCreator(){@Overridepublic PreparedStatement createPreparedStatement(Connection con)throws SQLException {PreparedStatement ps = con.prepareStatement(sql);ps.setInt(1, form.getUserId());ps.setString(2,form.getUserName());return ps;}});}}

 

 

package com.macower.spring.jdbc;import javax.sql.DataSource;import junit.framework.TestCase;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import org.springframework.jdbc.core.JdbcTemplate;public class CreateATable extends TestCase {/** * 测试用JdbcTemplate模板类建立数据表 * @throws Exception */public void testCreateATable() throws Exception {ApplicationContext ctx = new ClassPathXmlApplicationContext("app*.xml");DataSource dataSource = (DataSource) ctx.getBean("dataSource");//从bean中读取属性JdbcTemplate jdbcTemplate = new JdbcTemplate();//创建Jdbc模板类jdbcTemplate.setDataSource(dataSource);//为模板类添加数据源String sql = "create table tb_user(user_id int primary key, user_name varchar(60))";//创建一张表jdbcTemplate.execute(sql);/*执行后在数据库中显示的结果为 * mysql> desc tb_user;+-----------+-------------+------+-----+---------+-------+| Field | Type | Null | Key | Default | Extra |+-----------+-------------+------+-----+---------+-------+| user_id | int(11) | NO | PRI | NULL | || user_name | varchar(60) | YES | | NULL | |+-----------+-------------+------+-----+---------+-------+2 rows in set (0.07 sec) */}/** * 测试利用JdbcDaoSupport中的 getJdbcTemplate()进行数据的操作 * @throws Exception */public void testCreateTableByJdbcDaoSupport() throws Exception {ApplicationContext ctx = new ClassPathXmlApplicationContext("app*.xml");FormJdbcDao dao = (FormJdbcDao) ctx.getBean("formDao");dao.createTableByJdbcDaoSupport();}public void testAddForm() {Form form = new Form();form.setUserId(1);form.setUserName("Macower");ApplicationContext ctx = new ClassPathXmlApplicationContext("app*.xml");FormJdbcDao dao = (FormJdbcDao) ctx.getBean("formDao");dao.addForm(form);System.out.println("增加Form 成功");/* * 执行该函数时得到的结果： * mysql> select * from tb_user; *+---------+-----------+ *| user_id | user_name | *+---------+-----------+ * | 1 | Macower | *+---------+-----------+ *1 row in set (0.00 sec) */}public void testUdpateForm1() {Form form = new Form();form.setUserId(2);form.setUserName("Mahan");ApplicationContext ctx = new ClassPathXmlApplicationContext("app*.xml");FormJdbcDao dao = (FormJdbcDao) ctx.getBean("formDao");//更新数据形式1： getJdbcTemplate().update(sql, params);dao.updateForm1(form);/* * mysql> select * from tb_user;+---------+-----------+| user_id | user_name |+---------+-----------+| 1 | Macower || 2 | Mahan |+---------+-----------+2 rows in set (0.00 sec) */}/** * */public void testUdpateForm2() {Form form = new Form();form.setUserId(3);form.setUserName("voyage");ApplicationContext ctx = new ClassPathXmlApplicationContext("app*.xml");FormJdbcDao dao = (FormJdbcDao) ctx.getBean("formDao");//更新数据形式2： getJdbcTemplate().update(sql, params,Types[]);dao.updateForm2(form);/* * mysql> select * from tb_user;+---------+-----------+| user_id | user_name |+---------+-----------+| 1 | Macower || 2 | Mahan || 3 | voyage |+---------+-----------+3 rows in set (0.00 sec) */}public void testAddForm2(){Form form = new Form();form.setUserId(4);form.setUserName("Macower");ApplicationContext ctx = new ClassPathXmlApplicationContext("app*.xml");FormJdbcDao dao = (FormJdbcDao) ctx.getBean("formDao");//更新数据形式2： getJdbcTemplate().update(getJdbcTemplate().update(new PreparedStatementCreator(){//..});dao.addForm2(form);/*执行后查询后的结果 * mysql> select * from tb_user;+---------+-----------+| user_id | user_name |+---------+-----------+| 1 | Macower || 2 | Mahan || 3 | voyage || 4 | Macower |+---------+-----------+4 rows in set (0.00 sec) */}}

 

 

   getJdbcTemplate()中的方法图解

 

Spring 操作Jdbc具体步骤：

1： 配置 dataSource

2：配置 jdbcTemplate

必须特别注意只有用到了Spring的时候才能用到它的模板类

FormJdbcDao dao = new FormJdbcDao();

然后在 其方法中调用getJdbcTemplate()是不正确的会报告空指针异常

因此可以看出getJdbcTemplate()处理之前一定注入了值

<bean id="jdbcTemplate"class="org.springframework.jdbc.core.JdbcTemplate"><property name="dataSource" ref="dataSource" /></bean>

 

 

此时需要用类似下面的用法才能正确执行注入的相关操作

也才能执行相关的方法

ApplicationContext ctx = new ClassPathXmlApplicationContext("app*.xml");
  FormJdbcDao dao = (FormJdbcDao) ctx.getBean("formDao");

 

具体的介绍在代码部分已经做了介绍 自己动手调一下就可以了