一、相關概念

spring是一個一站式的框架，對不同持久層的技術都進行了封裝（處理資料庫技術，基本的crud操作即增刪改查），如JDBC、Hibermate、MaBatis、JPA等。

二、spring對JDBC的封裝使用步驟大體如下：

• 匯入jar包 spring-jdbc、spring-tx
• 建立DriveManagerDataSource物件，對資料庫進行配置
  
  • className
  • url
  • username
  • password
• 建立JdbcTemplate物件
  
  • 注入dataSource物件
• 呼叫JdbcTemplate封裝的方法進行sql操作
  
  • update(String sql , Object…arr) //增刪改
  • queryForObject(String sql , RowMapper rowMapper , Object…arr); //查詢，單個值或物件
  • query(String sql , RowMapper rowMapper , Object…arr); //查詢 ，list
  • 查詢方法的形參需要一個實現RowMapper介面的類，對資料進行封裝，詳見以下例項

三、利用spring的jdbcTemplate實現簡單的sql操作例項

1、建立工程，引入相關jar包

2、建立spring配置檔案並寫必要約束

<?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:aop="http://www.springframework.org/schema/aop"
    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
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"
 
>
</beans>

3、建表、配置資料庫及jdbcTemplate

• 建立一個簡單的book表
  
• 建立DataSource.properties

#DataSource.properities

driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/spring_jdbc_template_test?characterEncoding=UTF-8&useOldAliasMetadataBehavior=true
username=root
password=123456

• spring配置：

<!-- 掃描包下的所有註解 -->
    <context:component-scan base-package="com.jdbctemplate.book"></context:component-scan>

    <context:property-placeholder location="resource/DataSource.properties"></context:property-placeholder>
    <!-- 建立DataSource物件 -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${jdbc.driverClassName}"></property>
        <property name="url" value="${jdbc.url}"></property>
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
    <!-- 建立JdbcTemplate物件 -->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <constructor-arg name="dataSource" ref="dataSource"></constructor-arg>
    </bean>

4、建立Book例項類，儲存從資料庫取出的資料

public class Book {
    private String name;
    private float prive;
    public Book() {
        super();
    }
    public Book(String name, float prive) {
        super();
        this.name = name;
        this.prive = prive;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public float getPrive() {
        return prive;
    }
    public void setPrive(float prive) {
        this.prive = prive;
    }

    @Override
    public String toString() {
        return "Book [name=" + name + ", prive=" + prive +  "]";
    }
}

4、寫dao層介面

public interface BookDao {
    /**
     * 新增圖書
     * @param name
     * @param price
     * @return
     */
    public int addBook(String name , float price);
    /**
     * 刪除圖書
     * @param name
     * @return
     */
    public int delBook(String name);
    /**
     * 修改價格
     * @param name
     * @param price
     * @return
     */
    public int updateBook(String name,float price);
    /**
     * 返回所有Book資訊
     * @return
     */
    public List<Book> getAllBook();
    /**
     * 返回指定書名的圖書資訊
     * @param name
     * @return
     */
    public Book getBook(String name);
    /**
     * 返回指定書名的價格
     * @param name
     * @return
     */
    public float getPrice(String name);
}

5、寫BookDao的實現類，並配置

public class BookDaoImpl implements BookDao{
    // jdbc模板
    @Resource(name="jdbcTemplate")
    private  JdbcTemplate jdbcTemplate;
    public int addBook(String name, float price) {
        return jdbcTemplate.update("insert into book value(?,?)",name,price);
    }

    public int delBook(String name) {
        return jdbcTemplate.update("delete from book where name=?",name);
    }

    public int updateBook(String name, float price) {
        return jdbcTemplate.update("update book set price=? where name=?",price,name);
    }

    public List<Book> getAllBook() {
        return jdbcTemplate.query("select * from book", new BookRowMapper());
    }

    public Book getBook(String name) {
        return jdbcTemplate.queryForObject("select * from book where name=?", new BookRowMapper(),name);
    }

    public float getPrice(String name) {
        return jdbcTemplate.queryForObject("select price from book where name=?", Float.class);
    }

    private class BookRowMapper implements RowMapper<Book>{
        @Override
        public Book mapRow(ResultSet re, int arg1) throws SQLException {
            return new Book(re.getString("name"),re.getShort("price"));
        }

    }
}

<bean id="bookDaoImpl" class="com.jdbctemplate.book.dao.impl.BookDaoImpl"></bean>

6、寫BookService類

public class BookService {
    @Resource(name="bookDaoImpl")
    private BookDaoImpl bookDaoImpl;
    public List<Book> getAll() {
        return bookDaoImpl.getAllBook();
    }
    public Book get(String name) {
        return bookDaoImpl.getBook(name);
    }
    public float getPrice(String name) {
        return bookDaoImpl.getPrice(name);
    }
    public int add(String name,float price) {
        return bookDaoImpl.addBook(name, price);
    }
    public int delet(String name) {
        return bookDaoImpl.delBook(name);
    }
}

    <!-- 建立BookService物件 -->
    <bean id="bookService" class="com.jdbctemplate.book.service.BookService"></bean>

7、寫測試類

public class Test {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("resource/spring.xml");
        BookService bookService = (BookService) context.getBean("bookService");
        bookService.add("數學", 23.5F);
        bookService.add("語文", 20.5F);
        System.out.println(bookService.getAll());
    }
}

四、在過程中@Resource無法使用解決

在過程中註解@Resource無法使用，import javax.annotation.Resource;也一直紅線無法引入，改變JDK版本後奇怪的就好了，但專案中沒有錯誤，專案上總有個紅叉。解決：右鍵專案–properties–project Facets–java對於的版本改統一即可