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Spring(9)Spring和数据库编程

一、JdbcTemplate 概述

  在前面我们连接数据库通过传统的JDBC代码方式实现数据连接,可以参看Spring(2) IoC 的概念和作用中的例子,在JDBC中可能存在滥用try .. catch ... finally .. 语句,导致代码可读性和维护性下降,那么Spring提出了自己的解决方案,那就是 jdbcTemplte模板。

  它是 spring 框架中提供的一个对象,是对原始 Jdbc API 对象的简单封装。spring 框架为我们提供了很多的操作模板类。

  操作关系型数据的:JdbcTemplate;HibernateTemplate操作 nosql 数据库的:RedisTemplate。操作消息队列的:JmsTemplate等。

二、数据库资源配置

  在实际工作中我们大部分会配置为数据库连接池,我们可以使用Spring内部提供的类,也可以使用第三方数据库连接池或者WEB服务器中的JNDI获取数据源。如果使用第三方类,一般配置工程偏向于采用XML方式进行配置。这里我比较喜欢XML配置方式。

1.使用简单数据库配置

  我们通过Spring提供的一个类:org.springframework.jdbc.datasource.SimpleDriverDataSource,来完成数据库简单的配置,它不支持数据库连接池。

  

<bean id="dataSource" class="org.springframework.jdbc.datasource.SimpleDriverDataSource">
        <property name="username" value="root"/>
        <property name="password" value="root"/>
        <property name="dirverClass" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/spring"/>
    </bean>

2.使用第三方数据库连接池

  使用第三方数据库连接池,比如DBCP数据库连接池,我们引入相应的依赖包后就可以使用它了。

  

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysal.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/spring"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
        <property name="maxActive" value="255"/>
        <property name="maxIdle" value="5"/>
        <property name="maxWait" value="10000"/>
    </bean>

 3.使用JNDI数据库连接池

  在Tomcat和WebLogic等服务器上配置数据源,这时它存在一个JNDI的名称。通常可以通过Spring提供的JNDI机制获取对于的数据源。假设我们已经在Tomcat上配置了JNDI为jdbc/spring的数据源,这样我们可以在Web工程中获取这个JNDi数据源。

  

<bean id="dataSource" class="org.springframeworj.jndi.JndiObjectFactoryBean">
        <property name="jndiName" value="java:comp/env/jdbc/spring"/>
    </bean>

 三、JdbcTemplate 实现增删改查操作

 1.环境搭建

  我们还是以之前账户的例子进行举例。

(1)数据库建表(略)

(2)引入依赖文件

  

<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>com.xhbjava</groupId>
    <artifactId>Spring02</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.0.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.0.2.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.0.2.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.0.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>commons-dbutils</groupId>
            <artifactId>commons-dbutils</artifactId>
            <version>1.4</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.19</version>
        </dependency>


        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.4</version>
        </dependency>
    </dependencies>
</project>

(3)配置数据源

    <!-- 配置数据源 -->
    <bean id="dataSource"
        class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
        <property name="jdbcUrl"
            value="jdbc:mysql://localhost:3306/ssm?useSSL=true&amp;serverTimezone=UTC&amp;characterEncoding=UTF-8" />

        <property name="user" value="root"></property>
        <property name="password" value="root"></property>
    </bean>

 

(4)配置 JdbcTemplate

<!-- 数据库模板配置 -->
    <bean id="jdbcTemplate"
        class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>

    </bean>

2.JdbcTemplate简单操作

(1)保存

@Test
    public void testJdbcTemplateAdd() {
        //1.获取Spring容器
        ctx = new ClassPathXmlApplicationContext("bean.xml");
        //2.根据id获取bean对象
        JdbcTemplate jt =(JdbcTemplate)ctx.getBean("jdbcTemplate");
        //3.执行操作
        jt.execute("insert into account(name,money)values('jdbcTemplate',500)");
        
    }

 (2)更新

    @Test
    public void testJdbcTemplateUpdate() {
        //1.获取Spring容器
        ctx = new ClassPathXmlApplicationContext("bean.xml");
        //2.根据id获取bean对象
        JdbcTemplate jt =(JdbcTemplate)ctx.getBean("jdbcTemplate");
        //3.执行操作
        jt.update("update account set money = ? where id = ?",6000,6);
        
    }

(3)删除

@Test
    public void testJdbcTemplateDelete() {
        //1.获取Spring容器
        ctx = new ClassPathXmlApplicationContext("bean.xml");
        //2.根据id获取bean对象
        JdbcTemplate jt =(JdbcTemplate)ctx.getBean("jdbcTemplate");
        //3.执行操作
        jt.update("delete from  account where id = ? ",6);
        
    }

(4)查询所有

package com.xhbjava.pojo;

import java.sql.ResultSet;
import java.sql.SQLException;

import org.springframework.jdbc.core.RowMapper;

public class AccountRowMapper implements RowMapper<Account>{


public Account mapRow(ResultSet rs, int rowNum) throws SQLException {
    Account account = new Account();
    account.setId(rs.getInt("id"));
    account.setName(rs.getString("name"));
    account.setMoney(rs.getFloat("money"));
    return account;
}
}
@Test
    public void testJdbcTemplateQueryAll() {
        //1.获取Spring容器
        ctx = new ClassPathXmlApplicationContext("bean.xml");
        //2.根据id获取bean对象
        JdbcTemplate jt =(JdbcTemplate)ctx.getBean("jdbcTemplate");
        //3.执行操作
        List<Account> accounts = jt.query("select * from account where money > ? ", 
                new AccountRowMapper(), 500);
                for(Account o : accounts){
                System.out.println(o);
                }
        
    }

(5)单个查询

@Test
    public void testJdbcTemplateQueryOne() {
        //1.获取Spring容器
        ctx = new ClassPathXmlApplicationContext("bean.xml");
        //2.根据id获取bean对象
        JdbcTemplate jt =(JdbcTemplate)ctx.getBean("jdbcTemplate");
        //3.执行操作
        List<Account> as = jt.query("select * from account where id = ? ", 
                new AccountRowMapper(), 55);
                System.out.println(as.isEmpty()?"没有结果":as.get(0));
        
    }

(6)查询返回一行一列

@Test
    public void testJdbcTemplateQueryOneByOne() {
        //1.获取Spring容器
        ctx = new ClassPathXmlApplicationContext("bean.xml");
        //2.根据id获取bean对象
        JdbcTemplate jt =(JdbcTemplate)ctx.getBean("jdbcTemplate");
        //3.执行操作
        Integer total = jt.queryForObject("select count(*) from account where money > ? ",Integer.class,500);
                System.out.println(total);
        
    }

3.数据持久层Dao中使用JdbcTemplate

 (1)准备实体类(略)

  我们在原有基础上进行即可。

 (2)编写接口类和实现类

package com.xhbjava.service;

import java.util.List;

import com.xhbjava.pojo.Account;

/**
 * 账户的业务层接口
 * 
 * @author mr.wang
 *
 */
public interface IAccountService {
    /**
     * 保存账户
     */
    void saveAccount(Account account);
    /**
     * 更新账户
     * @param account
     */
    void updateAccount(Account account);
    /**
     * 删除账户
     * @param accountId
     */
     void deleteAccount(Integer accountId);

    /**
     * 根据id查询账户
     * 
     * @param accountId
     * @return
     */
     Account findById(Integer accountId);
     /**
      * 查询所有账户
      * @return
      */
     List<Account> findAll();
    


}
package com.xhbjava.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.xhbjava.dao.IAccountDao;
import com.xhbjava.pojo.Account;
import com.xhbjava.service.IAccountService;

/**
 * 账户业务层接口实现类
 * 
 * @author mr.wang
 *
 */
@Component("accountService")
public class AccountServiceImpl implements IAccountService {
    @Autowired
    private IAccountDao accountDao;

    public void saveAccount(Account account) {
        accountDao.saveAccount(account);

    }

    public void updateAccount(Account account) {
        accountDao.updateAccount(account);

    }

    public void deleteAccount(Integer accountId) {
        accountDao.deleteAccount(accountId);

    }

    public Account findById(Integer accountId) {
        return accountDao.findById(accountId);
    }

    public List<Account> findAll() {
        return accountDao.findAll();
    }

}
package com.xhbjava.dao;

import java.util.List;

import com.xhbjava.pojo.Account;

/**
 * 账户持久层接口
 * 
 * @author mr.wang
 *
 */
public interface IAccountDao {
    /**
     * 保存账户
     */
    void saveAccount(Account account);
    /**
     * 更新账户
     * @param account
     */
    void updateAccount(Account account);
    /**
     * 删除账户
     * @param accountId
     */
     void deleteAccount(Integer accountId);

    /**
     * 根据id查询账户
     * 
     * @param accountId
     * @return
     */
     Account findById(Integer accountId);
     /**
      * 查询所有账户
      * @return
      */
     List<Account> findAll();
     /**
      * 更加用户名成查找账户
      * @param sourceName
      * @return
      */
    Account findByName(String sourceName);

}
package com.xhbjava.dao.impl;

import java.util.List;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;

import com.xhbjava.dao.IAccountDao;
import com.xhbjava.pojo.Account;
import com.xhbjava.pojo.AccountRowMapper;

/**
 * 用户持久层接口实现类
 * 
 * @author mr.wang
 *
 */
@Component("accountDao")
public class AccountDaoImpl implements IAccountDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    public void saveAccount(Account account) {
        jdbcTemplate.update("insert into account(name,money) values(?,?)", account.getName(), account.getMoney());

    }

    public void updateAccount(Account account) {
        jdbcTemplate.update("update account set money = ? where id = ? ", account.getMoney(), account.getId());

    }

    public void deleteAccount(Integer accountId) {
        jdbcTemplate.update("delete from account  where id = ? ", accountId);

    }

    public Account findById(Integer accountId) {
        List<Account> list = jdbcTemplate.query("select * from account where id = ? ", new AccountRowMapper(),
                accountId);
        return list.isEmpty() ? null : list.get(0);
    }

    public List<Account> findAll() {
        List<Account> list = jdbcTemplate.query("select * from account  ", new AccountRowMapper());
        if (list.isEmpty()) {
            return null;
        }

        return list;
    }

    public Account findByName(String sourceName) {
        List<Account> list = jdbcTemplate.query("select * from account where name = ? ", new AccountRowMapper(),
                sourceName);
        if (list.isEmpty()) {
            return null;
        }
        if (list.size() > 1) {
            throw new RuntimeException("结果集不唯一,不是只有一个账户对象");
        }
        return list.get(0);
    }

}

(3)bean.xml

<?xml version="1.0" encoding="UTF-8"?>
<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"
    xmlns:util="http://www.springframework.org/schema/util"
    xmlns="http://www.springframework.org/schema/beans"
    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">
     <bean id="accountService" class="com.xhbjava.service.impl.AccountServiceImpl">
    </bean>
    <!-- 配置dao -->
    <bean id="accountDao" class="com.xhbjava.dao.impl.AccountDaoImpl">
    </bean>
    <!-- 数据库模板配置 -->
    <bean id="jdbcTemplate"
        class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    <!-- 数据库配置 -->
    <bean id="dataSource"
        class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
        <property name="jdbcUrl"
            value="jdbc:mysql://localhost:3306/ssm?useSSL=true&amp;serverTimezone=UTC&amp;characterEncoding=UTF-8"></property>
        <property name="user" value="root"></property>
        <property name="password" value="root"></property>
    </bean>

</beans>

(4)测试

package com.xhbjava.test;

import java.util.List;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.xhbjava.pojo.Account;
import com.xhbjava.pojo.AccountRowMapper;
import com.xhbjava.service.IAccountService;
import com.xhbjava.service.impl.AccountServiceImpl;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:bean.xml")
public class testSpring {

    private ApplicationContext ctx;
          @Autowired
        @Qualifier("accountService")
        private  IAccountService as;

    @Test
    public void testJdbcTemplateByDao() {
        
        Account account = new Account();
        account.setId(4);
        account.setMoney(19000f);
        as.updateAccount(account);
        
    }
}

 

posted on 2020-08-26 21:35  王小码  阅读(212)  评论(0编辑  收藏  举报