spring（六）JdbcTemplate，AOP事务控制（简单实现）

1. JdbcTemplate的使用及Dao的两种编写方式

1.1 注解式

	<context:component-scan base-package="com.java"></context:component-scan>

    <bean id="accountDao" class="com.java.dao.impl.AccountDaoImpl2"></bean>
    
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

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

@Repository
public class AccountDaoImpl2 implements IAccountDao {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Override
    public Account findAccountById(Integer accountId) {
        List<Account> accounts = jdbcTemplate.query("select * from account where id = ? ",new BeanPropertyRowMapper<Account>(Account.class),accountId);
        return accounts.isEmpty()? null : accounts.get(0);
    }

1.2 继承JdbcDaoSupport

	<bean id="accountDao" class="com.java.dao.impl.AccountDaoImpl">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
        <property name="url" value="jdbc:mysql://localhost:3306/eesy"></property>
        <property name="username" value="root"></property>
        <property name="password" value="root"></property>
    </bean>

public class AccountDaoImpl extends JdbcDaoSupport implements IAccountDao {

    @Override
    public Account findAccountById(Integer accountId) {
        List<Account> accounts = getJdbcTemplate().query("select * from account where id = ? ",new BeanPropertyRowMapper<Account>(Account.class),accountId);
        return accounts.isEmpty()? null : accounts.get(0);
    }

JdbcDaoSupport源码的简单实现（spring框架是已经写好了的不需要自己实现）

public class JdbcDaoSupport {

    private JdbcTemplate jdbcTemplate;

    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    public JdbcTemplate getJdbcTemplate() {
        return jdbcTemplate;
    }

    public void setDataSource(DataSource dataSource) {
        if (jdbcTemplate == null){
            jdbcTemplate = creatJdbcTemplate(dataSource);
        }
    }

    private JdbcTemplate creatJdbcTemplate(DataSource dataSource){
        return new JdbcTemplate(dataSource);
    }
}

2. AOP事务控制

2.1 基于XML的AOP实现事务控制

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

    <!--配置QueryRunner-->
    <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/eesy"></property>
        <property name="user" value="root"></property>
        <property name="password" value="root"></property>
    </bean>

    <bean id="connectionUtils" class="com.itheima.utils.ConnectionUtils">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <bean id="txManager" class="com.itheima.utils.TranscationManager">
        <property name="connectionUtils" ref="connectionUtils"></property>
    </bean>

    <aop:config>
        <aop:pointcut id="pt1" expression="execution(* com.itheima.service.impl.*.*(..))"></aop:pointcut>
        <aop:aspect id="txAdvice" ref="txManager">
            <aop:before method="beginTransaction" pointcut-ref="pt1"></aop:before>
            <aop:after-returning method="commit" pointcut-ref="pt1"></aop:after-returning>
            <aop:after-throwing method="rollback" pointcut-ref="pt1"></aop:after-throwing>
            <aop:after method="release" pointcut-ref="pt1"></aop:after>
        </aop:aspect>
    </aop:config>

Dao层

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;
    }
    @Override
    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);
        }
    }

Service层

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

    @Override
    public void transfer(String sourceName, String targetName, Float money) {
        System.out.println("transfer....");
        //2.1根据名称查询转出账户
        Account source = accountDao.findAccountByName(sourceName);
        //2.2根据名称查询转入账户
        Account target = accountDao.findAccountByName(targetName);
        //2.3转出账户减钱
        source.setMoney(source.getMoney()-money);

        int i=1/0;

        //2.4转入账户加钱
        target.setMoney(target.getMoney()+money);
        //2.5更新转出账户
        accountDao.updateAccount(source);
        //2.6更新转入账户
        accountDao.updateAccount(target);
    }

连接与线程的绑定和解绑

public class ConnectionUtils {
    private ThreadLocal<Connection> tl = new ThreadLocal<>();
    private DataSource dataSource;
	
	public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }
    
    public Connection getThreadConnection(){
        try {
            Connection conn = tl.get();
            if (conn == null){
                conn = dataSource.getConnection();
                tl.set(conn);
            }
            return conn;
        }catch (Exception e){
            throw new RuntimeException();
        }
    }

    public void removeConnection(){
         tl.remove();
    }
}

事务控制类

public class TranscationManager {
    private ConnectionUtils connectionUtils;
	
	public void setConnectionUtils(ConnectionUtils connectionUtils) {
        this.connectionUtils = connectionUtils;
    }
    /**
     * 开启事务
     */
    public  void beginTransaction(){
        try {
            connectionUtils.getThreadConnection().setAutoCommit(false);
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    /**
     * 提交事务
     */
    public  void commit(){
        try {
            connectionUtils.getThreadConnection().commit();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    /**
     * 回滚事务
     */
    public  void rollback(){
        try {
            connectionUtils.getThreadConnection().rollback();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    /**
     * 释放连接
     */
    public  void release(){
        try {
            connectionUtils.getThreadConnection().close();//还回连接池中
            connectionUtils.removeConnection();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}

2.2 基于注解的AOP实现事务控制

用注解配置时，通知的执行顺序会出问题，spring（五）有提到，所以一般用环绕通知实现注解AOP

	<!--扫描包-->
	<context:component-scan base-package="com.itheima"></context:component-scan>	
    <!--配置QueryRunner-->
    <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/eesy"></property>
        <property name="user" value="root"></property>
        <property name="password" value="root"></property>
    </bean>
    <!--开启spring注解AOP的支持-->
    <aop:aspectj-autoproxy></aop:aspectj-autoproxy>

@Component("txManager")
@Aspect
public class TranscationManager {
    @Autowired
    private ConnectionUtils connectionUtils;
    @Pointcut("execution(* com.itheima.service.impl.*.*(..))")
    private void pt1(){}
    /**
     * 开启事务
     */
//    @Before("pt1()")
    public  void beginTransaction(){
        try {
            connectionUtils.getThreadConnection().setAutoCommit(false);
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    /**
     * 提交事务
     */
//    @AfterReturning("pt1()")
    public  void commit(){
        try {
            connectionUtils.getThreadConnection().commit();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    /**
     * 回滚事务
     */
//    @AfterThrowing("pt1()")
    public  void rollback(){
        try {
            connectionUtils.getThreadConnection().rollback();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    /**
     * 释放连接
     */
//    @After("pt1()")
    public  void release(){
        try {
            connectionUtils.getThreadConnection().close();//还回连接池中
            connectionUtils.removeConnection();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    @Around("pt1()")
    public Object arroundAdvice(ProceedingJoinPoint proceedingJoinPoint){
        Object rtValue = null;
        try {
            Object[] args = proceedingJoinPoint.getArgs();
            this.beginTransaction();
            rtValue = proceedingJoinPoint.proceed(args);
            this.commit();
            return rtValue;
        } catch (Throwable throwable) {
            this.rollback();
            throw new RuntimeException(throwable);
        }finally {
            this.release();
        }
    }