Spring基于动态代理实现转账及实现事务控制

IDEA中创建maven项目
数据里表

整体构架

pom.xml

<?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>com.uek</groupId>
    <artifactId>spring02-study03-account-Transfer</artifactId>
    <version>1.0-SNAPSHOT</version>


    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.0.2.RELEASE</version>
        </dependency>

        <!--spring整合junit的jar-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</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>5.1.6</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>
    </dependencies>
</project>

entity

/**
 * 账户的实体类
 */
public class Account implements Serializable {

    private Integer id;
    private String name;
    private Float 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 Float getMoney() {
        return money;
    }

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

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

service

/**
 * 账户的业务层接口
 */
public interface IAccountService {

    //查询所有
    List<Account> findAllAccount() throws SQLException;

    //根据id查询
    Account findAccountById(Integer accountId) throws SQLException;

    //插入
    void saveAccount(Account account) throws SQLException;

    //更新
    void updateAccount(Account account) throws SQLException;

    //删除
    void deleteAccount(Integer accountId) throws SQLException;

    /**
     * 转账
     * @param sourceName   转出账户名称
     * @param targetName   转入账户名称
     * @param money        转账金额
     */
    void transfer(String sourceName,String targetName,Float money) throws SQLException;


}

/**
 * 账户的业务层实现类
 * 事务的控制应该都是在业务层的
 */
public class AccountServiceImpl implements IAccountService {

    private IAccountDao accountDao;

    public void setAccountDao(IAccountDao accountDao) {
        this.accountDao = accountDao;
    }

    //查询所有
    public List<Account> findAllAccount() throws SQLException {
        return accountDao.findAllAccount();
    }

    //根据id查询
    public Account findAccountById(Integer accountId) throws SQLException {
        return accountDao.findAccountById(accountId);
    }

    //插入
    public void saveAccount(Account account) throws SQLException {
        accountDao.saveAccount(account);
    }

    //更新
    public void updateAccount(Account account) throws SQLException {
        accountDao.updateAccount(account);
    }

    //删除
    public void deleteAccount(Integer accountId) throws SQLException {
       accountDao.deleteAccount(accountId);
    }

    //转账
    public void transfer(String sourceName, String targetName, Float money) throws SQLException {
        System.out.println("transfer开始执行.......");
        //1).根据名称查询转出账户
        Account source = accountDao.findAccountByName(sourceName);
        //2).根据名称查询转入账户
        Account target = accountDao.findAccountByName(targetName);
        //3).转出账户减钱
        source.setMoney(source.getMoney() - money);
        //4).转入账户加钱
        target.setMoney(target.getMoney() + money);
        //5).更新转出账户
        accountDao.updateAccount(source);
        //6).更新转入账户
        accountDao.updateAccount(target);
    }
}

dao

/**
 * 账户的持久层接口
 */
public interface IAccountDao {

    //查询所有
    List<Account> findAllAccount() throws SQLException;

    //根据id查询
    Account findAccountById(Integer accountId);

    //插入
    void saveAccount(Account account);

    //更新
    void updateAccount(Account account);

    //删除
    void deleteAccount(Integer accountId);

    /**
     * 根据名称查询账户
     * @param accountName
     * @return  如果有唯一的一个结果就返回，如果没有结果就返回null
     *          如果结果集超过一个就抛异常
     */
    Account findAccountByName(String accountName);

}

/**
 * 账户的持久层实现类
 */
public class AccountDaoImpl implements IAccountDao {

    private QueryRunner runner;
    private ConnectionUtils connectionUtils;

    public void setRunner(QueryRunner runner) {
        this.runner = runner;
    }

    public void setConnectionUtils(ConnectionUtils connectionUtils) {
        this.connectionUtils = connectionUtils;
    }

    //查询所有
    public List<Account> findAllAccount() {
        try {
            return runner.query(connectionUtils.getThreadConnection(),"select * from account",new BeanListHandler<Account>(Account.class));
        }catch (Exception e){
            throw new RuntimeException(e);
        }

    }

    //根据id查询
    public Account findAccountById(Integer accountId) {
        try {
            return runner.query(connectionUtils.getThreadConnection(),"select * from account where id = ? ",new BeanHandler<Account>(Account.class),accountId);
        }catch (Exception e){
            throw new RuntimeException(e);
        }
    }

    //插入
    public void saveAccount(Account account) {
        try {
            runner.update(connectionUtils.getThreadConnection(),"insert into account(name,money)values(?,?)",account.getName(),account.getMoney());
        }catch (Exception e){
            throw new RuntimeException(e);
        }
    }

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

    //删除
    public void deleteAccount(Integer accountId) {
        try {
            runner.update(connectionUtils.getThreadConnection(),"delete from account where id =?",accountId);
        }catch (Exception e){
            throw new RuntimeException(e);
        }
    }

    //根据名称查询账户
    public Account findAccountByName(String accountName) {
        try {
            List<Account>  accounts = runner.query(connectionUtils.getThreadConnection(),"select * from account where name = ? ",new BeanListHandler<Account>(Account.class),accountName);
            if(accounts == null || accounts.size() == 0){
                return null;
            }
            if(accounts.size()>1){
                throw new RuntimeException("结果集不唯一，数据有问题");
            }
            return accounts.get(0);
        }catch (Exception e){
            throw new RuntimeException(e);
        }
    }
}

utils

/**
 * 连接的工具类，它用于从数据源中获取一个连接，并且实现和线程的绑定
 */
public class ConnectionUtils {

    private ThreadLocal<Connection> tl = new ThreadLocal<Connection>();

    private DataSource dataSource;

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    public void setTl(ThreadLocal<Connection> tl) {
        this.tl = tl;
    }

    //获取当前线程上的连接
    public Connection getThreadConnection() throws SQLException {
        //1.先从ThreadLocal上获取
        Connection conn = tl.get();
        //2.判断当前线程上是否有连接
        if(conn == null){
            //3.从数据源中获取一个连接，并且存入ThreadLocal中
            conn = dataSource.getConnection();
            tl.set(conn);
        }
        //4.返回当前线程上的连接
        return conn;
    }

    //把连接和线程解绑
    public void removeConnection(){
        tl.remove();
    }


}

/**
 * 和事务管理相关的工具类，它包含了开启事务，提交事务，回滚事务和释放连接
 */
public class TransactionManager {

    //获取当前线程的Connection
    private ConnectionUtils connectionUtils;

    public void setConnectionUtils(ConnectionUtils connectionUtils) {
        this.connectionUtils = connectionUtils;
    }

    //开启事务
    public void beginTransaction() throws SQLException {
        connectionUtils.getThreadConnection().setAutoCommit(false);
    }

    //提交事务
    public void commit() throws SQLException {
        connectionUtils.getThreadConnection().commit();
    }

    //回滚事务
    public void rollback() throws SQLException {
        connectionUtils.getThreadConnection().rollback();
    }

    //释放连接
    public void release() throws SQLException {
        //还回连接池
        connectionUtils.getThreadConnection().close();
        connectionUtils.removeConnection();
    }
}

factory

/**
 * 用于创建Service的代理的工厂
 */
public class BeanFactory {

    private IAccountService accountService;
    private TransactionManager txManager;

    public void setTxManager(TransactionManager txManager) {
        this.txManager = txManager;
    }

    public final void setAccountService(IAccountService accountService) {
        this.accountService = accountService;
    }

    //获取Service代理对象
    public IAccountService getAccountService() {
        return (IAccountService)Proxy.newProxyInstance(accountService.getClass().getClassLoader(), accountService.getClass().getInterfaces(), new InvocationHandler() {
            /**
             * 添加事务的支持
             * @param proxy
             * @param method
             * @param args
             * @return
             * @throws Throwable
             */
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                Object rtValue = null;
                try {
                    //1.开启事务
                    txManager.beginTransaction();
                    //2.执行操作
                    rtValue = method.invoke(accountService,args);
                    //3.提交事务
                    txManager.commit();
                    //4.返回结果
                    return rtValue;
                }catch (Exception e){
                    //5.回滚操作
                    txManager.rollback();
                    throw new RuntimeException(e);
                }finally {
                    //6.释放连接
                    txManager.release();
                }
            }
        });
    }
}

bean.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
          http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!--配置代理的service-->
    <bean id="proxyAccountService" factory-bean="beanFactory" factory-method="getAccountService"></bean>

    <!--配置beanfactory-->
    <bean id="beanFactory" class="com.uek.factory.BeanFactory">
        <!--注入service-->
        <property name="accountService" ref="accountService"></property>
        <!--注入事务管理器-->
        <property name="txManager" ref="txManager"></property>
    </bean>

    <!--配置service-->
    <bean id="accountService" class="com.uek.service.impl.AccountServiceImpl">
        <!--注入dao-->
        <property name="accountDao" ref="accountDao"></property>
    </bean>

    <!--配置dao对象-->
    <bean id="accountDao" class="com.uek.dao.impl.AccountDaoImpl">
        <!--注入QueryRunner-->
        <property name="runner" ref="runner"></property>
        <!--注入ConnectionUtils-->
        <property name="connectionUtils" ref="connectionUtils"></property>

    </bean>

    <!--配置QueryRunner对象-->
    <bean id="runner" class="org.apache.commons.dbutils.QueryRunner" scope="prototype"></bean>

    <!--配置数据源-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <!--连接数据库的必备信息-->
        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/spring?useUnicode=true&characterEncoding=utf-8&useSSL=false"></property>
        <property name="user" value="root"></property>
        <property name="password" value="root"></property>
    </bean>

    <!--配置Connection的工具类 ConnectionUtils-->
    <bean id="connectionUtils" class="com.uek.utils.ConnectionUtils">
        <!--注入数据源-->
        <property name="dataSource" ref="dataSource" ></property>
    </bean>

    <!--配置事务管理-->
    <bean id="txManager" class="com.uek.utils.TransactionManager">
        <!--注入ConnectionUtils-->
        <property name="connectionUtils" ref="connectionUtils"></property>
    </bean>
</beans>

测试类

/**
 * 使用Junit单元测试
 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:bean.xml")
public class AccountServiceTest {

    @Autowired
    @Qualifier("proxyAccountService")
    private IAccountService ias;

    //测试转账
    @Test
    public void testTransfer() throws SQLException {
        ias.transfer("aaa","bbb",100f);
    }
}