Spring之JDBC数据访问

Spring JDBC是Spring所提供的持久层技术,它的主要目标是降低使用JDBC API的门槛,以一种更直接,更简介,更简单的方式使用JDBC API, 在Spring JDBC里,仅需做那些与业务相关的DML操作,而将资源获取,Statment创建,资源释放以及异常处理等繁杂而乏味的工作交给Spring JDBC.

虽然ORM的框架已经成熟丰富,但是JDBC的灵活,直接的特性,依然让他拥有自己的用武之地,如在完全依赖查询模型动态产生查询语句的综合查询系统中,Hibernaye,MyBatis,JPA等框架都无法使用,这里JDBC是唯一的选择.

主要内容:学习使用JdbcTemplate API和如何使用Spring管理 JdbcTemplate

1. JdbcTemplate入门

1.1 创建项目

项目名: spring-jdbc

引入jar包
Spring之JDBC数据访问

<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>3.8.1</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>aopalliance</groupId>
        <artifactId>aopalliance</artifactId>
        <version>1.0</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.8.10</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-aspects -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
        <version>4.3.7.RELEASE</version>
    </dependency>
      <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>4.3.10.RELEASE</version>
  </dependency>
  <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context-support</artifactId>
      <version>4.3.11.RELEASE</version>
  </dependency>

  <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>4.3.10.RELEASE</version>
  </dependency>
  <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>4.3.10.RELEASE</version>
  </dependency>

  <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-beans</artifactId>
      <version>4.3.10.RELEASE</version>
  </dependency>

  <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-expression</artifactId>
      <version>4.3.10.RELEASE</version>
  </dependency>

  <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
  <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>4.3.9.RELEASE</version>
  </dependency>
  <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
  <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.38</version>
  </dependency>
  <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.1.2</version>
  </dependency>

  <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.14</version>
  </dependency>

  <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.38</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/org.springframework/spring-test -->
  <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>4.3.10.RELEASE</version>
      <scope>test</scope>
  </dependency>

  <!-- https://mvnrepository.com/artifact/com.mchange/mchange-commons-java -->
  <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>mchange-commons-java</artifactId>
      <version>0.2.11</version>
  </dependency>

  <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot -->
  <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot</artifactId>
      <version>1.5.7.RELEASE</version>
  </dependency>
  <!-- https://mvnrepository.com/artifact/com.mchange/c3p0 -->
  <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.5.2</version>
  </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>4.3.9.RELEASE</version>
  </dependency>

导入日志:log4j.properties

1.2 创建数据库

数据库名: springjdbc

创建角色表:

CREATE TABLE `role` (
  `rid` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '角色id',
  `rname` VARCHAR(20) NOT NULL COMMENT '角色名',
  `alias` VARCHAR(20) NOT NULL COMMENT '角色别名',
  PRIMARY KEY (`rid`)
)

INSERT INTO role (rid,rname,alias)
VALUES(1,'admin','系统管理员'),(2,'dispatcher','调度员');

1.3 测试代码

 @Test
 public  void test1() throws Exception {
        //TODO 测试jdbcTemplate简单使用
        //1.创建c3p0链接池
        ComboPooledDataSource dataSource  = new ComboPooledDataSource();
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/springjdbc");
        dataSource.setUser("root");
        dataSource.setPassword("111");


        //创建jdbcTemplate对象
        JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);

        //创建sql语句
        String sql = "insert into role (rid , rname ,alias) value (? , ?,?);";
        jdbcTemplate.update(sql,"3","visitor","游客");
 }

2. Spring管理JdbcTemplate

1. 创建Role.java

public class Role {

    private Integer cid;
    private String  rname;
    private String  alias;
	
    //setter getter
}

2. RoleDao.java

public interface RoleDao {

     //增
     void save(Role role);

     //删除
     void delete(Integer id);

     //改
     void update(Role role);

     //查
     Role getById(Integer id);

     //查
     int getTotalCount();

     //查
     List<Role> getAll();

}

3. 创建RoleDaoImpl.java

创建数据源(连接池),JdbcTemplate,RoleDao交给Spring容器管理(IOC)

注意: 可以自己在RoleDaoImpl中添加 JdbcTemplate变量,如果不自动装载记得添加变量的set方法,

标准的操作,我们可以让RoleDaoImpl 继承 JdbcDaoSupport, 因为(org.springframework.jdbc.core.support.JdbcDaoSupport)类提供了JdbcTemplate对象以及对应的获取和设置方法.不用自己在实现类中添加JdbcTemplate变量!!

JdbcTemplate  // Spring操作数据模板类(工具类)

JdbcTemplate.update(sql,ArgsObj....);   //DML 
JdbcTemplate.execute(sql)    //DDL DCL
//DQL 查询单个  
jdbcTemplate.queryForObject(String var1, RowMapper<T> var2, Object... var3);
RowWapper<T> 将结果封装的处理器; 得到Result解析成实体类对象即可!  

//查询所有
jdbcTemplate.query(String var1, RowMapper<T> var2, Object... var3);

RoleDaoImple代码:

public class RoleDaoImpl extends JdbcDaoSupport implements RoleDao {


    public void save(Role role) {
    //TODO 插入数据
       String sql = "INSERT INTO role (rname,alias) value (?,?) ;";
       getJdbcTemplate().update(sql,role.getRname(),role.getAlias());
    }

    public void delete(Integer id) {
     //TODO 根据id删除
        String sql = "delete from role where rid = ? ;";
        getJdbcTemplate().update(sql,id);
    }

    public void update(Role role) {
      //TODO 修改role信息
        String  sql="update role set rname = ? , alias = ? where rid = ? ;" ;
        getJdbcTemplate().update(sql,role.getRname(),role.getAlias(),role.getRid());
    }

    public Role getById(Integer id) {

        String sql = "select * from  role where rid = ? ;";

        //直接查询
       // Role role = getJdbcTemplate().queryForObject(sql, new Object[]{id}, Role.class);
        Role role = (Role) getJdbcTemplate().queryForObject(sql, new Object[]{id}, new RowMapper<Object>() {

            public Object mapRow(ResultSet resultSet, int index) throws SQLException {
                //将一行数据解析成一个java对象

                return  mapRowHandler(resultSet);
            }
        });

        return role;
    }

    public int getTotalCount() {

        String sql = "select count(*) from role ;";

        Integer count = getJdbcTemplate().queryForObject(sql,Integer.class);

        return count;
    }

    //查询所有
    public List<Role> getAll() {

        String  sql = "select * from role";

        List<Role> list =  getJdbcTemplate().query(sql, new RowMapper<Role>() {
            public Role mapRow(ResultSet resultSet, int i) throws SQLException {

                return mapRowHandler(resultSet);
            }
        });

        return list;
    }

    private Role mapRowHandler(ResultSet resultSet) throws  SQLException{
           Role role = new Role();
           role.setRid(resultSet.getInt("rid"));
           role.setRname(resultSet.getString("rname"));
           role.setAlias(resultSet.getString("alias"));
           return  role;
    }


}

4. 创建数据库配置文件

文件名:db.properties

位置: src下/ maven项目 resources文件夹下

jdbc.jdbcUrl=jdbc:mysql://localhost:3306/springjdbc
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.user=root
jdbc.password=111

5.编写IOC配置

文件名:applicationContext.xml

位置:src下 / maven项目 resources文件夹下

<?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"
       xmlns:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <!-- bean definitions here -->

       <context:component-scan base-package="com.bruceliu.spring"></context:component-scan>
       <context:property-placeholder  location="db.properties"></context:property-placeholder>


        <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" p:jdbcUrl="${jdbc.jdbcUrl}"
              p:driverClass="${jdbc.driverClass}"
              p:user="root"
              p:password="111"
        />

        <!-- bean jdbcTemplate -->
        <bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">

            <property name="dataSource" ref="dataSource"/>
        </bean>


        <bean name="roleDao" class="com.bruceliu.spring.dao.impl.RoleDaoImpl">
            <property name="jdbcTemplate" ref="jdbcTemplate"/>
        </bean>

</beans>

测试:

 @Test
    public  void test2(){
     //TODO 测试使用配置文件

        ApplicationContext context =new  ClassPathXmlApplicationContext("applicationContext.xml");
        RoleDao dao = context.getBean("roleDao", RoleDaoImpl.class);

        Role byId = dao.getById(2);
        System.out.println(byId);

        List<Role> all = dao.getAll();

        System.out.println("all = " + all);
    }