SSM-Spring-19：Spring中JdbcTemplate

------------吾亦无他,唯手熟尔，谦卑若愚，好学若饥-------------

Spring自带一个ORM持久化框架JdbcTemplate，他可以说是jdbc的加强版，但是对最细微的控制肯定做不到像jdbc那么细，那么性能高，他的出现是为了让jdbc更加便于使用

下面我说一下我这篇博客要干嘛，

一，简单的JdbcTemplate做出来的案例

二，除了自带的Spring-jdbc，补充c3p0,druid,dbcp三种DataSource数据源

1.案例查询图书

　　1.1数据表：

　　　　

　　接下来就是java程序开发工具idea做的事了

　　1.2引入依赖jar包：

　　　　以前的jar包外，还需要spring-jdbc和jdbc的mysql的jar

        <!--spring jdbc-->
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>4.3..RELEASE</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.</version>
        </dependency>

　　1.3分层开发开始，先是entity实体类层

　　　　Book

package cn.dawn.day21jdbctemplate.entity;

public class Book {
    private Integer bookID;
    private String bookName;
    private String bookAuthor;
    private Integer bookPrice;

    @Override
    public String toString() {
        return "Book{" +
                "bookID=" + bookID +
                ", bookName='" + bookName + '\'' +
                ", bookAuthor='" + bookAuthor + '\'' +
                ", bookPrice=" + bookPrice +
                '}';
    }

    public Book() {
    }

    public Integer getBookID() {
        return this.bookID;
    }

    public void setBookID(Integer bookID) {
        this.bookID = bookID;
    }

    public String getBookName() {
        return this.bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public String getBookAuthor() {
        return this.bookAuthor;
    }

    public void setBookAuthor(String bookAuthor) {
        this.bookAuthor = bookAuthor;
    }

    public Integer getBookPrice() {
        return this.bookPrice;
    }

    public void setBookPrice(Integer bookPrice) {
        this.bookPrice = bookPrice;
    }
}

　　1.3dao层

　　　　一个接口IBookDAO

package cn.dawn.day21jdbctemplate.dao;

import cn.dawn.day21jdbctemplate.entity.Book;

import java.util.List;

/**
 * Created by Dawn on 2018/3/13.
 */
public interface IBookDAO {
    public List<Book> findAllBooks();
}

　　　　它的实现类BookDAOImpl

package cn.dawn.day21jdbctemplate.dao;

import cn.dawn.day21jdbctemplate.entity.Book;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

/**
 * Created by Dawn on 2018/3/13.
 */
public class BookDAOImpl extends JdbcDaoSupport implements IBookDAO {
    public List<Book> findAllBooks() {
        String sql="select * from book";
        List<Book> lists = this.getJdbcTemplate().query(sql, new RowMapper<Book>() {
            public Book mapRow(ResultSet rs, int i) throws SQLException {
                Book book=new Book();
                book.setBookAuthor(rs.getString("bookAuthor"));
                book.setBookID(rs.getInt("bookId"));
                book.setBookName(rs.getString("bookName"));
                book.setBookPrice(rs.getInt("bookPrice"));
                return book;
            }
        });
        return lists;
    }
}

　　　　这儿有几点要说的，他实现了JdbcTemplate，是为了一会给这个类注入数据源等操作，子类继承了父类的方法属性，所以这个类才能和数据库打交道

　　　　ResultSet就是数据库的单行记录，i就是此单行记录是符合你查出来的中的第几条，先把案例配通

　　1.4service层

　　　　一个接口IBookService

package cn.dawn.day21jdbctemplate.service;

import cn.dawn.day21jdbctemplate.entity.Book;

import java.util.List;

/**
 * Created by Dawn on 2018/3/13.
 */
public interface IBookService {
    public List<Book> findAllBooks();
}

　　　　它的实现类BookService

package cn.dawn.day21jdbctemplate.service;

import cn.dawn.day21jdbctemplate.dao.IBookDAO;
import cn.dawn.day21jdbctemplate.entity.Book;

import java.util.List;

/**
 * Created by Dawn on 2018/3/13.
 */
public class BookServiceImpl implements IBookService{
    private IBookDAO dao;

    public List<Book> findAllBooks() {
        return dao.findAllBooks();
    }

    public IBookDAO getDao() {
        return dao;
    }

    public void setDao(IBookDAO dao) {
        this.dao = dao;
    }
}

　　　　dao层的接口声明成成员变量，并且提供get/set方法，一会要注入进来dao层的实现

　　1.5我做了个一步到位的操作，将Driver,url,username,pwd这些jdbc连接数据库的条件提到了propertiess文件中

　　　　jdbc.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql:///s2228
jdbc.username=root
jdbc.password=

　　1.6就是书写大配置文件了

　　　　起名随意，一会单测方法中能合的上就行，以.xml结尾

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

    <!--配置jdbc。properties-->
    <context:property-placeholder location="classpath:jdbc.properties"></context:property-placeholder>

    <!--自带的持久化框架的数据源-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${jdbc.driver}"></property>
        <property name="url" value="${jdbc.url}"></property>
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>

    <!--配置jdbctemplate-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <!--dao-->
    <bean id="bookDao" class="cn.dawn.day21jdbctemplate.dao.BookDAOImpl">
        <property name="jdbcTemplate" ref="jdbcTemplate"></property>
    </bean>

    <!--service-->
    <bean id="bookService" class="cn.dawn.day21jdbctemplate.service.BookServiceImpl">
        <property name="dao" ref="bookDao"></property>
    </bean>
</beans>

　　1.7书写测试方法

package cn.dawn.day21JdbcTemplate;

import cn.dawn.day21jdbctemplate.entity.Book;
import cn.dawn.day21jdbctemplate.service.IBookService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

/**
 * Created by Dawn on 2018/3/3.
 */
public class test20180313 {
    @Test
    /*aop代理工厂bean异常增强*/
    public void t01(){
        ApplicationContext context=new ClassPathXmlApplicationContext("ApplicationContext-day21JdbcTemplate.xml");
        IBookService service = (IBookService) context.getBean("bookService");
        List<Book> allBooks = service.findAllBooks();
        for (Book item:allBooks) {
            System.out.println(item);
        }

    }
}

　　

案例完

下面说说另外三种数据源的配置，不同公司使用的不是完全一样，所以我提及几种，使用方法，在上方的案例中只要引入jar包，把xml中dateSource那个bean替换掉就好

　　1.dbcp

　　　　1.1引入jar包

        <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-dbcp2 -->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.1.</version>
        </dependency>

　　　　1.2xml文件中的dataSource

    <bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource">
        <property name="driverClassName" value="${jdbc.driver}"></property>
        <property name="url" value="${jdbc.url}"></property>
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>

　　2.c3p0

　　　　2.1jar包

        <!-- https://mvnrepository.com/artifact/c3p0/c3p0 -->
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>

　　　　2.2xml中

     <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"></property>
        <property name="jdbcUrl" value="${jdbc.url}"></property>
        <property name="user" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>

　　3.druid　　这个是中国阿里巴巴开发的

　　　　3.1jar包

        <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.</version>
        </dependency>

　　　　3.2xml文件中

    <!--阿里的Druid-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driver}"></property>
        <property name="url" value="${jdbc.url}"></property>
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>