Spring基础学习（十）——JDBCTemplate

ゞ浴缸里的玫瑰 2022-05-31 03:23 185阅读 0赞

JDBCTemplate是spring提供的用于操作JDBC的工具类，类似于J2EE中我们自己写的JDBCUtil，依赖于链接池DataSource,这里我选择阿里的数据库连接池druid，数据库就用常用的MySQL.

首先是建表——只做说明，本例是简单的用户之间转账的例子，所以是一个表格，包括有id,username,password,money四列

导入jar包，需要在pom.xml文件中添加下述代码：

<dependency>
    	    <groupId>org.springframework</groupId>
    	    <artifactId>spring-jdbc</artifactId>
    	    <version>4.3.14.RELEASE</version>
    	</dependency>
    
    		<dependency>
    		    <groupId>com.alibaba</groupId>
    		    <artifactId>druid</artifactId>
    		    <version>1.1.6</version>
    		</dependency>
    
    		<dependency>
    		    <groupId>mysql</groupId>
    		    <artifactId>mysql-connector-java</artifactId>
    		    <version>5.1.45</version>
    		</dependency>

pojo类：

public class User implements Serializable {
    
    	/**
    	 * 
    	 */
    	private static final long serialVersionUID = 1L;
    
    	private Integer id;
    	private String userName;
    	private String password;
    	private Double money;
    
    	public User() {
    		// TODO Auto-generated constructor stub
    	}
    
    	/* (non-Javadoc)
    	 * @see java.lang.Object#toString()
    	 */
    	@Override
    	public String toString() {
    		return "User [id=" + id + ", userName=" + userName + ", password=" + password + ", money=" + money + "]";
    	}
    
    	/**
    	 * @param id
    	 * @param userName
    	 * @param password
    	 * @param money
    	 */
    	public User(Integer id, String userName, String password, Double money) {
    		this.id = id;
    		this.userName = userName;
    		this.password = password;
    		this.money = money;
    	}
    
    	/**
    	 * @return the id
    	 */
    	public Integer getId() {
    		return id;
    	}
    
    	/**
    	 * @param id the id to set
    	 */
    	public void setId(Integer id) {
    		this.id = id;
    	}
    
    	/**
    	 * @return the userName
    	 */
    	public String getUserName() {
    		return userName;
    	}
    
    	/**
    	 * @param userName the userName to set
    	 */
    	public void setUserName(String userName) {
    		this.userName = userName;
    	}
    
    	/**
    	 * @return the password
    	 */
    	public String getPassword() {
    		return password;
    	}
    
    	/**
    	 * @param password the password to set
    	 */
    	public void setPassword(String password) {
    		this.password = password;
    	}
    
    	/**
    	 * @return the money
    	 */
    	public Double getMoney() {
    		return money;
    	}
    
    	/**
    	 * @param money the money to set
    	 */
    	public void setMoney(Double money) {
    		this.money = money;
    	}
    
    	/**
    	 * @return the serialversionuid
    	 */
    	public static long getSerialversionuid() {
    		return serialVersionUID;
    	}
    
    }

Dao层

import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.jdbc.core.JdbcTemplate;
    import org.springframework.stereotype.Repository;
    
    import net.seehope.springjdbc.pojo.User;
    
    @Repository
    public class UserDao {
    	@Autowired
    	private JdbcTemplate jdbcTemplate;
    
    	public void addUser(User user) {
    		jdbcTemplate.update("insert into user(username,password,money) values(?,?,?)", user.getUserName(),
    				user.getPassword(), user.getMoney());
    	}
    
    	/**
    	 * 加钱
    	 * @param id
    	 * @param money
    	 */
    	public void in(Integer id, Double money) {
    		jdbcTemplate.update("update user set money=money + ? where id =?", money, id);
    	}
    
    	/**
    	 * 扣钱
    	 * @param id
    	 * @param money
    	 */
    	public void out(Integer id, Double money) {
    		jdbcTemplate.update("update user set money=money - ? where id =?", money, id);
    	}
    }

service层：

@Service
    public class UserServiceImpl implements UserService {
    	@Autowired
    	UserDao dao;
    
    	/* (non-Javadoc)
    	 * @see net.seehope.springjdbc.service.UserService#transfer(java.lang.Integer, java.lang.Integer, java.lang.Double)
    	 */
    	public void transfer(Integer inner, Integer outer, Double money) {
    		// TODO Auto-generated method stub
    		dao.out(outer, money);
    		dao.in(inner, money);
    	}
    
    }

xml文件配置：

<?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:context="http://www.springframework.org/schema/context"
    	xmlns:tx="http://www.springframework.org/schema/tx"
    	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-4.3.xsd
    		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
    		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">
    
    
    <context:annotation-config></context:annotation-config> 
    
    
    <context:component-scan base-package="net.seehope"/>
      
     <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
     destroy-method="close">  
             
     <property name="url" value="${url}" />
     <property name="username" value="${username}" />
     <property name="password" value="${password}" />
     <property name="driverClassName" value="${driverClassName}" />
     <property name="filters" value="${filters}" />  
         
     <property name="maxActive" value="${maxActive}" />
             
     <property name="initialSize" value="${initialSize}" />
             
     <property name="maxWait" value="${maxWait}" />
             
     <property name="minIdle" value="${minIdle}" />  
         
     <property name="timeBetweenEvictionRunsMillis" value="${timeBetweenEvictionRunsMillis}" />
             
     <property name="minEvictableIdleTimeMillis" value="${minEvictableIdleTimeMillis}" />
     <property name="validationQuery" value="${validationQuery}" />
     <property name="testWhileIdle" value="${testWhileIdle}" />
     <property name="testOnBorrow" value="${testOnBorrow}" />
     <property name="testOnReturn" value="${testOnReturn}" />
     <property name="maxOpenPreparedStatements" value="${maxOpenPreparedStatements}" />
             
     <property name="removeAbandoned" value="${removeAbandoned}" />
             
     <property name="removeAbandonedTimeout" value="${removeAbandonedTimeout}" />
             
     <property name="logAbandoned" value="${logAbandoned}" />
     </bean>
    
    
     <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
     <property name="dataSource" ref="dataSource"></property>
     </bean>
    
    </beans>

properties文件的设置就不做展示了，毕竟里面有链接数据库的账户和密码

测试类：

import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import org.springframework.test.context.ContextConfiguration;
    import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
    
    import net.seehope.springjdbc.service.UserService;
    
    /** 
    * 这里用到了JUnit和spring的整合，我会在下一篇的博文中讲解，这里先用着，spring和JUnit的整合作为测试类十分好用
    */
    @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration(locations = { "classpath:sping/applicationContext.xml" })
    public class SpringJdbcTest {
    	@Autowired
    	UserService service;
    
    	@Test
    	public void serviceTest() {
    		service.transfer(1, 2, 3.0);
    	}
    
    }

测试结果，数据库中id=1的用户money-3，id=2的用户money+3

在实际开发中，很少见用Spring的JDBCTemplate去写dao层的，因为有更加好用的dao层框架，比如mybaits和hibernate，这些dao层框架更加常用，所以JDBCTemplate看看就好，不过本文中用到的阿里的druit数据库连接池我推荐大家使用，在上文xml文件配置的数据库连接池也推荐大家直接使用，这是阿里官方的设置，没有什么特殊情况下都是不错，直接copy使用即可。