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前言:
前面有讲过 Spring IOC以及AOP的基本使用方法, 这里就再来讲下Spring JDBCTemplate的使用方法.
一, 概述
这里先说一下Spring 整合的一些模板:
从上图中可以看出 Spring为各种支持的持久化技术,都提供了简单操作的模板和回调.
二, 使用JdbcTemplate
2.1 Spring JDBC是Spring提供的持久层技术
简化JDBC API开发,使用上和Apache公司的DBUtils框架非常类似
具体开发使用的jar包结构如图:
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2.2, Spring配置连接池
1, 配置Spring的内置的连接池
1 <!-- 配置Spring的内置的连接池 --> 2 <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> 3 <property name="driverClassName" value="com.mysql.jdbc.Driver"/> 4 <property name="url" value="jdbc:mysql:///spring_day02"/> 5 <property name="username" value="root"/> 6 <property name="password" value="123"/> 7 </bean>
2, 配置DBCP连接池
1 <!-- 配置DBCP连接池 --> 2 <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"> 3 <property name="driverClassName" value="com.mysql.jdbc.Driver"/> 4 <property name="url" value="jdbc:mysql:///spring_day02"/> 5 <property name="username" value="root"/> 6 <property name="password" value="123"/> 7 </bean>
注: 这里如果使用DBCP连接池的话还需要导入Spring 整合DBCP的两个jar包.
3. C3P0连接池
1 <!-- 配置C3P0连接池 --> 2 <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> 3 <property name="driverClass" value="com.mysql.jdbc.Driver"/> 4 <property name="jdbcUrl" value="jdbc:mysql:///spring_day02"/> 5 <property name="user" value="root"/> 6 <property name="password" value="123"/> 7 </bean>
4,引入属性文件: 写jdbc.properties 文件, 然后直接将配置文件注入到Spring中
jdbc.properties 配置文件:
jdbc.driverClass=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql:///spring_day02 jdbc.user=root jdbc.password=123
1 <!-- 引入方式一:引入属性文件 --> 2 <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> 3 <property name="location" value="classpath:jdbc.properties"/> 4 </bean> 5 <!--引入方式二:引入context的约束--> 6 <context:property-placeholder location="classpath:jdbc.properties"/>
三, 开发案例, 使用Spring JDBCTemplate 进行CRUD操作.
Customer.java:
1 public class Customer { 2 private Integer cid; 3 private String cname; 4 private Integer age; 5 public Integer getCid() { 6 return cid; 7 } 8 public void setCid(Integer cid) { 9 this.cid = cid; 10 } 11 public String getCname() { 12 return cname; 13 } 14 public void setCname(String cname) { 15 this.cname = cname; 16 } 17 public Integer getAge() { 18 return age; 19 } 20 public void setAge(Integer age) { 21 this.age = age; 22 } 23 @Override 24 public String toString() { 25 return "Customer [cid=" + cid + ", cname=" + cname + ", age=" + age 26 + "]"; 27 } 28 29 }
CustomerDao.java:
1 /** 2 * 完成对Customer的CRUD的操作 3 * 4 */ 5 public class CustomerDao extends JdbcDaoSupport { 12 13 public void save(Customer customer) { 14 this.getJdbcTemplate().update("insert into customer values (null,?,?)", 15 customer.getCname(), customer.getAge()); 16 } 17 18 public void update(Customer customer) { 19 this.getJdbcTemplate().update( 20 "update customer set cname = ?,age = ? where cid = ?", 21 customer.getCname(), customer.getAge(), customer.getCid()); 22 } 23 24 public void delete(Integer cid) { 25 this.getJdbcTemplate() 26 .update("delete from customer where cid = ?", cid); 27 } 28 29 public Integer findCount() { 30 int count = this.getJdbcTemplate().queryForInt( 31 "select count(*) from customer"); 32 return count; 33 } 34 35 public String findNameById(Integer cid) { 36 String cname = this.getJdbcTemplate().queryForObject( 37 "select cname from customer where cid = ?", String.class, cid); 38 return cname; 39 } 40 41 public Customer findById(Integer cid) { 42 Customer customer = this.getJdbcTemplate().queryForObject( 43 "select * from customer where cid = ?", 44 new BeanPropertyRowMapper<Customer>(Customer.class), cid); 45 return customer; 46 } 47 48 public List<Customer> findAll() { 49 List<Customer> list = this.getJdbcTemplate().query("select * from customer", 50 new BeanPropertyRowMapper<Customer>(Customer.class)); 51 return list; 52 } 53 }
SpringDemo2.java 测试类:
1 @RunWith(SpringJUnit4ClassRunner.class) 2 @ContextConfiguration("classpath:applicationContext2.xml") 3 public class SpringDemo2 { 4 5 @Resource(name="customerDao") 6 private CustomerDao customerDao; 7 8 @Test 9 public void demo1(){ 10 11 Customer customer = new Customer(); 12 customer.setCname("马大帅"); 13 customer.setAge(48); 14 15 customerDao.save(customer); 16 } 17 18 @Test 19 public void demo2(){ 20 21 Customer customer = new Customer(); 22 customer.setCid(8); 23 customer.setCname("马小帅"); 24 customer.setAge(38); 25 26 customerDao.update(customer); 27 } 28 29 @Test 30 public void demo3(){ 31 customerDao.delete(7); 32 } 33 34 @Test 35 public void demo4(){ 36 int count = customerDao.findCount(); 37 System.out.println(count); 38 } 39 40 @Test 41 public void demo5(){ 42 String cname = customerDao.findNameById(8); 43 System.out.println(cname); 44 } 45 46 @Test 47 public void demo6(){ 48 Customer customer = customerDao.findById(8); 49 System.out.println(customer); 50 } 51 52 @Test 53 public void demo7(){ 54 List<Customer> customers = customerDao.findAll(); 55 for (Customer customer : customers) { 56 System.out.println(customer); 57 } 58 } 59 }
applicationContext.xml 配置文件:
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xmlns:context="http://www.springframework.org/schema/context" 5 xsi:schemaLocation=" 6 http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd 7 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> 8 9 10 <context:property-placeholder location="classpath:jdbc.properties"/> 11 12 <!-- 配置C3P0连接池 --> 13 <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> 14 <property name="driverClass" value="${jdbc.driverClass}"/> 15 <property name="jdbcUrl" value="${jdbc.url}"/> 16 <property name="user" value="${jdbc.user}"/> 17 <property name="password" value="${jdbc.password}"/> 18 </bean> 19 20 21 <!-- 配置DAO --> 22 <bean id="customerDao" class="cn.itcast.jdbc.demo2.CustomerDao"> 23 <property name="dataSource" ref="dataSource"/> 24 </bean> 25 </beans>
好了, 一个基本的CRUD操作就完成了, 在这里我们可以发现配置文件特别的简洁, 我们只是给customerDao注入了一个dataSource , 然后在CustomerDao.java中就可以用this.getJdbcTemplate()获取到JDBCTemplate的实例了, 这个原理是因为我们的CustomerDao继承了 JdbcDaoSupport , 这里我们就来看下它的源码:
首先我们使用this.getJdbcTemplate而获取到一个jdbcTemplate实例:
1 /** 2 * Return the JdbcTemplate for this DAO, 3 * pre-initialized with the DataSource or set explicitly. 4 */ 5 public final JdbcTemplate getJdbcTemplate() { 6 return this.jdbcTemplate; 7 }
那么又返回的这个this.jdbcTemplate是否是有值得呢? 再看源代码原来是在我们setDataSource的时候生成了jdbcTemplate实例.
1 /** 2 * Set the JDBC DataSource to be used by this DAO. 3 */ 4 public final void setDataSource(DataSource dataSource) { 5 if (this.jdbcTemplate == null || dataSource != this.jdbcTemplate.getDataSource()) { 6 this.jdbcTemplate = createJdbcTemplate(dataSource); 7 initTemplateConfig(); 8 } 9 }
好了, 到了这里就没有了, 关于JDBCTemplate的总结就这么多了. (该睡觉了.)
[Spring框架]Spring JDBCTmplate基础入门总结.
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原文地址:http://www.cnblogs.com/wang-meng/p/5645395.html