#编程式事务控制#TransactionTemplate#[email protected]

测试环境：IDEA 2020.2、MySQL 8.0.16

项目结构：

pom.xml的内容：

<?xml version="1.0" encoding="UTF-8"?>
<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>org.example</groupId>
    <artifactId>P041_programmatic_transaction_control</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.1.8.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.16</version>
        </dependency>

        <!--连接池-->
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.2</version>
        </dependency>

        <!--单元测试-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.1.8.RELEASE</version>
        </dependency>
    </dependencies>

</project>

bean.xml的内容：

<?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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">
    <!--ComboPooledDataSource只能通过set方法(property标签)注入连接相关的信息-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" scope="singleton">
        <property name="driverClass" value="com.mysql.cj.jdbc.Driver"></property>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test?characterEncoding=UTF8&amp;serverTimezone=Asia/Shanghai"></property>
        <property name="user" value="root"></property>
        <property name="password" value="123456"></property>
    </bean>

    <bean class="org.springframework.jdbc.datasource.DataSourceTransactionManager" id="transactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <bean class="org.springframework.transaction.support.TransactionTemplate" id="transactionTemplate">
        <property name="transactionManager" ref="transactionManager"></property>
    </bean>

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

    <bean class="cn.liuxingchang.Dao.impl.AccountDaoImpl" id="accountDao">
        <property name="jdbcTemplate" ref="jdbcTemplate"></property>
    </bean>

    <bean id="accountService" class="cn.liuxingchang.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"></property>
        <property name="transactionTemplate" ref="transactionTemplate"></property>
    </bean>
</beans>

MySQL数据库：

database：test port：3306 table：account

#编程式事务控制#TransactionTemplate#[email protected]

Account.java的内容：

package cn.liuxingchang.Domain;

import java.io.Serializable;

public class Account implements Serializable {
    private Integer id;
    private String name;
    private Double money;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Double getMoney() {
        return money;
    }

    public void setMoney(Double money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", money=" + money +
                '}';
    }
}

AccountDao.java的内容：

package cn.liuxingchang.Dao;

import cn.liuxingchang.Domain.Account;

public interface AccountDao {
    void updateAccount(Account account);
    Account findAccountByName(String name);
}

AccountDaoImpl.java的内容：

package cn.liuxingchang.Dao.impl;

import cn.liuxingchang.Dao.AccountDao;
import cn.liuxingchang.Domain.Account;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;

import java.util.List;

public class AccountDaoImpl implements AccountDao {
    private JdbcTemplate jdbcTemplate;
    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    public void updateAccount(Account account) {
        try {
            jdbcTemplate.update("update account set name = ?, money = ? where id = ?",
                    account.getName(), account.getMoney(), account.getId());
        } catch(Exception e) {
            throw new RuntimeException(e);
        }
    }

    public Account findAccountByName(String name) {
        try {
            List<Account> accounts = jdbcTemplate.query("select * from account where name = ?",
                    new BeanPropertyRowMapper<Account>(Account.class), name);

            if(accounts == null || accounts.size() == 0) {
                throw new RuntimeException("找不到目标账户！");
            } else if(accounts.size() == 1) {
                return accounts.get(0);
            } else {
                throw new RuntimeException("账户不唯一！");
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

AccountService.java的内容：

package cn.liuxingchang.service;

public interface AccountService {

    void transfer(String sourceName, String targetName, Double money);
}

AccountServiceImpl.java的内容：

package cn.liuxingchang.service.impl;

import cn.liuxingchang.Dao.AccountDao;
import cn.liuxingchang.Domain.Account;
import cn.liuxingchang.service.AccountService;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.TransactionCallback;
import org.springframework.transaction.support.TransactionTemplate;

public class AccountServiceImpl implements AccountService {
    private AccountDao accountDao;
    public void setAccountDao(AccountDao accountDao) {
        this.accountDao = accountDao;
    }

    private TransactionTemplate transactionTemplate;
    public void setTransactionTemplate(TransactionTemplate transactionTemplate) {
        this.transactionTemplate = transactionTemplate;
    }

    public void transfer(final String sourceName, final String targetName, final Double money) {
        transactionTemplate.execute(new TransactionCallback<Object>() {
            public Object doInTransaction(TransactionStatus transactionStatus) {
                Account source = accountDao.findAccountByName(sourceName);
                Account target = accountDao.findAccountByName(targetName);
                source.setMoney(source.getMoney() - money);
                target.setMoney(target.getMoney() + money);
                accountDao.updateAccount(source);
                int i = 1 / 0; //用来测试事务的一致性
                accountDao.updateAccount(target);
                return null;
            }
        });
    }
}

Test.java的内容：

import cn.liuxingchang.service.AccountService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {
    ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
    AccountService accountService = context.getBean("accountService", AccountService.class);

    @org.junit.Test
    public void transferTest() {
        accountService.transfer("Zhao", "Qian", 1.0);
    }
}