概述：

JdbcTemplet是Spring提供的对数据库操作的一个类

准备工作：

1.导入依赖坐标：

<dependencies><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>5.2.1.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-core</artifactId><version>5.2.1.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-expression</artifactId><version>5.2.1.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-tx</artifactId><version>5.2.1.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.2.2.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-orm</artifactId><version>5.2.1.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-test</artifactId><version>5.2.1.RELEASE</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.23</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.20</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version><scope>test</scope></dependency>
</dependencies>

2.编写一个Dao接口和实现类

public interface BookDao {}@Service("bookDao")
public class BookDaoImpl implements BookDao {}
}

3.编写Book实体类

public class Book {private String title;private String content;public Book(String title, String content) {this.title = title;this.content = content;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}public String getContent() {return content;}public void setContent(String content) {this.content = content;}
}

4.在配置文件中编写bean以及开启注解扫描

<?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:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/context  http://www.springframework.org/schema/context/spring-context.xsd"><context:component-scan base-package="com.zhang"/>
<!--    将jdbcTemplate加入容器--><bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<!--        注入数据库连接池对象--><property name="dataSource" ref="dataSource"/></bean>
<!--    引用外部数据库配置文件--><context:property-placeholder location="dataBase.properties"/>
<!--    创建数据库连接池--><bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"><property name="driverClassName" value="${jdbc.driverClass}"/><property name="url" value="${jdbc.url}"/><property name="username" value="${jdbc.userName}"/><property name="password" value="${jdbc.password}"/></bean>
</beans>

测试保存方法：

public interface BookDao {//测试保存方法void saveBook(Book book);
}
//持久层实现
@Service("bookDao")
public class BookDaoImpl implements BookDao {//自动注入jdbcTemplate@Autowiredprivate JdbcTemplate jdbcTemplate;//实现保存方法@Overridepublic void saveBook(Book book) {jdbcTemplate.update("insert into book values(?,?)",book.getTitle(),book.getContent());}
}//测试代码
@Testpublic void test(){ApplicationContext applicationContext=new ClassPathXmlApplicationContext("bean.xml");BookDaoImpl bookService = applicationContext.getBean("bookDao", BookDaoImpl.class);bookService.saveBook(new Book("daomu","123"));}

增删改都要使用update这个方法，只需要改变sql和参数列表即可，但要注意每一个？与参数一一对应

测试查询方法：

public interface BookDao {//测试查询List<Book> findAll();
}
//查询返回集合
@Service("bookDao")
public class BookDaoImpl implements BookDao {//自动注入jdbcTemplate@Autowiredprivate JdbcTemplate jdbcTemplate;@Overridepublic List<Book> findAll() {return jdbcTemplate.query("select * from book",//需要传入class对象以便反射封装数据new BeanPropertyRowMapper<>(Book.class));}
}

查询返回对象：

@Service("bookDao")
public class BookDaoImpl implements BookDao {//自动注入jdbcTemplate@Autowiredprivate JdbcTemplate jdbcTemplate;@Overridepublic Book findByTitle(String title) {return jdbcTemplate.queryForObject("select * from book where title=?",new BeanPropertyRowMapper<>(Book.class),title);}
}