Spring 的JDBC模板

（一）Spring 其实提供了很多的持久化技术的模板类简化编程。
包括：
– JDBC
– Hibernate3.0
– IBatis（MyBatis）
– JPA

今天主要讲一下JDBC模板

（二）实战

1. 在mysql中创建student表

            包括id  name   age属性
   

   2.Maven依赖的引入

      所需maven依赖如下
   

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>groupId</groupId><artifactId>hello</artifactId><version>1.0-SNAPSHOT</version><dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency><!-- https://mvnrepository.com/artifact/org.springframework/spring-context --><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>4.3.18.RELEASE</version></dependency><!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.46</version></dependency><!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc --><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>4.3.18.RELEASE</version></dependency><!-- https://mvnrepository.com/artifact/org.springframework/spring-tx --><dependency><groupId>org.springframework</groupId><artifactId>spring-tx</artifactId><version>4.3.18.RELEASE</version></dependency><!-- https://mvnrepository.com/artifact/commons-dbcp/commons-dbcp --><dependency><groupId>commons-dbcp</groupId><artifactId>commons-dbcp</artifactId><version>1.4</version></dependency><!-- https://mvnrepository.com/artifact/commons-pool/commons-pool --><dependency><groupId>commons-pool</groupId><artifactId>commons-pool</artifactId><version>1.6</version></dependency><!-- https://mvnrepository.com/artifact/com.mchange/c3p0 --><dependency><groupId>com.mchange</groupId><artifactId>c3p0</artifactId><version>0.9.5.2</version></dependency></dependencies>
</project>

3.

Student.java文件

public class Student {private Integer age;private String name;private Integer id;......}

StudentMapper.java

public class StudentMapper  implements RowMapper<Student> {public Student mapRow(ResultSet resultSet, int i) throws SQLException {Student st=new Student();st.setId(resultSet.getInt("Id"));st.setName(resultSet.getString("name"));st.setAge(resultSet.getInt("age"));return st;}
}

StudentService.java

public interface StudentService {public void setDataSource(DataSource ds);public void create(String name, Integer age);public Student getStudent(Integer id);public List<Student> listStudents();public void delete(Integer id);public void update(Integer id, Integer age);
}

StudentJDBCTemplate.java

public class StudentJDBCTemplate implements StudentService {private DataSource dataSource;private JdbcTemplate jdbcTemplateObject;public void setDataSource(DataSource dataSource) {this.dataSource = dataSource;this.jdbcTemplateObject = new JdbcTemplate(dataSource);}public void create(String name, Integer age) {String SQL = "insert into Student (name, age) values (?, ?)";jdbcTemplateObject.update( SQL, name, age);System.out.println("Created Record Name = " + name + " Age = " + age);return;}public Student getStudent(Integer id) {String SQL = "select * from Student where id = ?";Student student = jdbcTemplateObject.queryForObject(SQL,new Object[]{id}, new StudentMapper());return student;}public List<Student> listStudents() {String SQL = "select * from Student";List <Student> students = jdbcTemplateObject.query(SQL,new StudentMapper());return students;}public void delete(Integer id) {String SQL = "delete from Student where id = ?";jdbcTemplateObject.update(SQL, id);System.out.println("Deleted Record with ID = " + id );return;}public void update(Integer id, Integer age) {String SQL = "update Student set age = ? where id = ?";jdbcTemplateObject.update(SQL, age, id);System.out.println("Updated Record with ID = " + id );return;}
}

MainApp.java测试文件

public class MainApp {public static void main(String[] args) {ApplicationContext context =new ClassPathXmlApplicationContext("beans.xml");StudentJDBCTemplate studentJDBCTemplate =(StudentJDBCTemplate)context.getBean("studentJDBCTemplate");System.out.println("------Records Creation--------" );studentJDBCTemplate.create("Zara", 11);studentJDBCTemplate.create("Nuha", 2);studentJDBCTemplate.create("Ayan", 15);System.out.println("------Listing Multiple Records--------" );List<Student> students = studentJDBCTemplate.listStudents();for (Student record : students) {System.out.print("ID : " + record.getId() );System.out.print(", Name : " + record.getName() );System.out.println(", Age : " + record.getAge());}System.out.println("----Updating Record with ID = 2 -----" );studentJDBCTemplate.update(2, 20);System.out.println("----Listing Record with ID = 2 -----" );Student student = studentJDBCTemplate.getStudent(2);System.out.print("ID : " + student.getId() );System.out.print(", Name : " + student.getName() );System.out.println(", Age : " + student.getAge());}
}

4.配置文件的编写

    提供几种方式，具体如下：

<?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/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context-4.3.xsd
"><context:component-scan base-package="com.txp.dao"/><!--配置Spring的内接连接池--><bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"><property name="driverClassName" value="com.mysql.jdbc.Driver"/><property name="url" value="jdbc:mysql:///mybatis"/><property name="username" value="root"/><property name="password" value="root"/></bean><!--配置DBCP连接池--><bean id="dataSource1" class="org.apache.commons.dbcp.BasicDataSource"><property name="driverClassName" value="com.mysql.jdbc.Driver"/><property name="url" value="jdbc:mysql:///mybatis"/><property name="username" value="root"/><property name="password" value="root"/></bean><!--配置DBCP连接池--><bean id="dataSource2" class="com.mchange.v2.c3p0.ComboPooledDataSource"><property name="driverClass" value="com.mysql.jdbc.Driver"/><property name="jdbcUrl" value="jdbc:mysql:///mybatis"/><property name="user" value="root"/><property name="password" value="root"/></bean><!--引入外部文件的方式：一--><bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"><property name="location" value="classpath:jdbc.properties"/></bean><!--引入外部文件的方式：二--><context:property-placeholder location="classpath:jdbc.properties"/><!--配置JDBC模板--><bean id="studentJDBCTemplate" class="com.txp.dao.StudentJDBCTemplate"><property name="dataSource" ref="dataSource"/></bean>
</beans> 

jdbc.properties文件内容

jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql:///mybatis
jdbc.username=root
jdbc.password=root

最后的结果