Spring 基础知识五

喜欢ヅ旅行 2023-10-10 11:07 4阅读 0赞

**第一 Spring 事务控制API介绍**

1.1 PlatformTransactionManager:

此接口是 spring 的事务管理器，它里面提供了我们常用的操作事务的方法，如下图：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70][]

1.2 开发中常用的PlatformTransactionManager接口实现类:

![20200515234654639.PNG][]

1.3 TransactionDefinition

它是事务对象，里面有如下方法：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 1][]

1.3.1 事务的隔离级别

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 2][]

1.3.2 事务的传播行为

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 3][]

1.3.3 超时时间

默认值是-1，没有超时限制。如果有，以秒为单位进行设置。

1.3.4 是否是只读事务

建议查询时设置为只读。

1.4 TransactionStatus

此接口提供的是事务具体的运行状态，方法介绍如下图：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 4][]

**第二 基于 XML 方式进行事务控制**

核心代码:

package com.zzg.transaction.entity;
    
    import java.io.Serializable;
    
    @SuppressWarnings("serial")
    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 + "]";
    	}
    
    }
    
    
    package com.zzg.transaction.dao;
    
    import com.zzg.transaction.entity.Account;
    
    public interface IAccountDao {
    	/**
    	* 根据 id 查询账户信息
    	* @param id
    	* @return
    	*/
    	Account findAccountById(Integer id);
    	/**
    	* 根据名称查询账户信息
    	* @return
    	*/
    	Account findAccountByName(String name);
    	/**
    	* 更新账户信息
    	* @param account
    	*/
    	void updateAccount(Account account);
    }
    
    
    package com.zzg.transaction.dao.impl;
    
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.List;
    
    import org.springframework.jdbc.core.RowMapper;
    import org.springframework.jdbc.core.support.JdbcDaoSupport;
    
    import com.zzg.transaction.dao.IAccountDao;
    import com.zzg.transaction.entity.Account;
    
    public class AccountDaoImpl extends JdbcDaoSupport implements IAccountDao {
    
    	@Override
    	public Account findAccountById(Integer id) {
    		// TODO Auto-generated method stub
    		List<Account> list = getJdbcTemplate().query("select * from account where id = ? ", new AccountRowMapper(), id);
    		return list.isEmpty() ? null : list.get(0);
    	}
    
    	@Override
    	public Account findAccountByName(String name) {
    		// TODO Auto-generated method stub
    		List<Account> list = getJdbcTemplate().query("select * from account where name = ? ", new AccountRowMapper(),
    				name);
    		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);
    	}
    
    	@Override
    	public void updateAccount(Account account) {
    		getJdbcTemplate().update("update account set money = ? where id = ? ",account.getMoney(),account.getId());
    	}
    
    	class AccountRowMapper implements RowMapper<Account> {
    
    		@Override
    		public Account mapRow(ResultSet rs, int rowNum) throws SQLException {
    			// TODO Auto-generated method stub
    			Account account = new Account();
    			account.setId(rs.getInt("id"));
    			account.setName(rs.getString("name"));
    			account.setMoney(rs.getFloat("money"));
    			return account;
    		}
    
    	}
    
    }
    
    
    package com.zzg.transaction.service;
    
    import com.zzg.transaction.entity.Account;
    
    public interface IAccountService {
    	/**
    	* 根据 id 查询账户信息
    	* @param id
    	* @return
    	*/
    	Account findAccountById(Integer id);//查
    	/**
    	* 转账
    	* @param sourceName 转出账户名称
    	* @param targeName 转入账户名称
    	* @param money 转账金额
    	*/
    	void transfer(String sourceName,String targeName,Float money);//增删改
    }
    
    
    package com.zzg.transaction.service.impl;
    
    import com.zzg.transaction.dao.IAccountDao;
    import com.zzg.transaction.entity.Account;
    import com.zzg.transaction.service.IAccountService;
    
    public class AccountServiceImpl implements IAccountService {
    	private IAccountDao accountDao;
    
    	public void setAccountDao(IAccountDao accountDao) {
    		this.accountDao = accountDao;
    	}
    
    	@Override
    	public Account findAccountById(Integer id) {
    		// TODO Auto-generated method stub
    		return accountDao.findAccountById(id);
    	}
    
    	@Override
    	public void transfer(String sourceName, String targeName, Float money) {
    		// TODO Auto-generated method stub
    		//1.根据名称查询两个账户
    		Account source = accountDao.findAccountByName(sourceName);
    		Account target = accountDao.findAccountByName(targeName);
    		//2.修改两个账户的金额
    		source.setMoney(source.getMoney()-money);//转出账户减钱
    		target.setMoney(target.getMoney()+money);//转入账户加钱
    		//3.更新两个账户
    		accountDao.updateAccount(source);
    		int i=1/0;
    		accountDao.updateAccount(target);
    	}
    
    }

初始化数据库脚本

create table account(
    id int primary key auto_increment,
    name varchar(40),
    money float
    )character set utf8 collate utf8_general_ci;

演示代码和配置文件

package com.zzg.transaction;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    import com.zzg.transaction.entity.Account;
    import com.zzg.transaction.service.IAccountService;
    
    public class TransactionTest {
    
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		// 1.获取 Spring 容器
    		ApplicationContext ac = new ClassPathXmlApplicationContext("transactionXML.xml");
    		IAccountService service = (IAccountService) ac.getBean("accountService");
    		Account account = service.findAccountById(1);
    		System.out.println(account.toString());
    		
    		service.transfer("张三", "李四", 100f);
    		
    	}
    
    }

<?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:context="http://www.springframework.org/schema/context"
    	xmlns:tx="http://www.springframework.org/schema/tx"
    	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/tx 
     http://www.springframework.org/schema/tx/spring-tx.xsd
     http://www.springframework.org/schema/aop
     http://www.springframework.org/schema/aop/spring-aop.xsd">
    	
    	<context:property-placeholder
    		location="classpath:jdbc.properties" />
    
    	
    	<bean id="accountService"
    		class="com.zzg.transaction.service.impl.AccountServiceImpl">
    		<property name="accountDao" ref="accountDao"></property>
    	</bean>
    	
    	<bean id="accountDao"
    		class="com.zzg.transaction.dao.impl.AccountDaoImpl">
    		
    		<property name="dataSource" ref="dataSource"></property>
    	</bean>
    
    	
    	<bean id="dataSource"
    		class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    		<property name="driverClassName" value="${jdbc.driverClass}"></property>
    		<property name="url" value="${jdbc.url}"></property>
    		<property name="username" value="${jdbc.username}"></property>
    		<property name="password" value="${jdbc.password}"></property>
    	</bean>
    
    	
    	<bean id="transactionManager"
    		class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    		
    		<property name="dataSource" ref="dataSource"></property>
    	</bean>
    
    	
    	<tx:advice id="txAdvice"
    		transaction-manager="transactionManager">
    		<tx:attributes>
    			
    			<tx:method name="*" read-only="false"
    				propagation="REQUIRED" />
    			<tx:method name="find*" read-only="true"
    				propagation="SUPPORTS" />
    		</tx:attributes>
    	</tx:advice>
    
    	
    	<aop:config>
    		
    		<aop:pointcut
    			expression="execution(* com.zzg.transaction.service.impl.*.*(..))" id="pt1" />
    		
    		<aop:advisor advice-ref="txAdvice" pointcut-ref="pt1" />
    	</aop:config>
    
    </beans>

**第三 基于 注解 方式进行事务控制**

核心代码:

package com.zzg.transaction.dao;
    
    import com.zzg.transaction.entity.Account;
    
    public interface IAccountDao {
    	/**
    	* 根据 id 查询账户信息
    	* @param id
    	* @return
    	*/
    	Account findAccountById(Integer id);
    	/**
    	* 根据名称查询账户信息
    	* @return
    	*/
    	Account findAccountByName(String name);
    	/**
    	* 更新账户信息
    	* @param account
    	*/
    	void updateAccount(Account account);
    }
    
    
    package com.zzg.transaction.dao.impl;
    
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.jdbc.core.JdbcTemplate;
    import org.springframework.jdbc.core.RowMapper;
    import org.springframework.stereotype.Repository;
    
    import com.zzg.transaction.dao.IAccountDao;
    import com.zzg.transaction.entity.Account;
    
    @Repository("accountDao")
    public class AccountDaoImpl implements IAccountDao {
    	@Autowired
    	private JdbcTemplate jdbcTemplate;
    	@Override
    	public Account findAccountById(Integer id) {
    		// TODO Auto-generated method stub
    		List<Account> list = jdbcTemplate.query("select * from account where id = ? ", new AccountRowMapper(), id);
    		return list.isEmpty() ? null : list.get(0);
    	}
    
    	@Override
    	public Account findAccountByName(String name) {
    		// TODO Auto-generated method stub
    		List<Account> list = jdbcTemplate.query("select * from account where name = ? ", new AccountRowMapper(),
    				name);
    		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);
    	}
    
    	@Override
    	public void updateAccount(Account account) {
    		jdbcTemplate.update("update account set money = ? where id = ? ",account.getMoney(),account.getId());
    	}
    
    	class AccountRowMapper implements RowMapper<Account> {
    
    		@Override
    		public Account mapRow(ResultSet rs, int rowNum) throws SQLException {
    			// TODO Auto-generated method stub
    			Account account = new Account();
    			account.setId(rs.getInt("id"));
    			account.setName(rs.getString("name"));
    			account.setMoney(rs.getFloat("money"));
    			return account;
    		}
    
    	}
    
    }
    
    
    package com.zzg.transaction.service;
    
    import com.zzg.transaction.entity.Account;
    
    public interface IAccountService {
    	/**
    	* 根据 id 查询账户信息
    	* @param id
    	* @return
    	*/
    	Account findAccountById(Integer id);//查
    	/**
    	* 转账
    	* @param sourceName 转出账户名称
    	* @param targeName 转入账户名称
    	* @param money 转账金额
    	*/
    	void transfer(String sourceName,String targeName,Float money);//增删改
    }
    
    
    
    package com.zzg.transaction.service.impl;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.transaction.annotation.Propagation;
    import org.springframework.transaction.annotation.Transactional;
    
    import com.zzg.transaction.dao.IAccountDao;
    import com.zzg.transaction.entity.Account;
    import com.zzg.transaction.service.IAccountService;
    
    @Service("accountService")
    @Transactional(readOnly=true,propagation=Propagation.SUPPORTS)
    public class AccountServiceImpl implements IAccountService {
    	@Autowired
    	private IAccountDao accountDao;
    
    	@Override
    	public Account findAccountById(Integer id) {
    		// TODO Auto-generated method stub
    		return accountDao.findAccountById(id);
    	}
    
    	@Override
    	public void transfer(String sourceName, String targeName, Float money) {
    		// TODO Auto-generated method stub
    		//1.根据名称查询两个账户
    		Account source = accountDao.findAccountByName(sourceName);
    		Account target = accountDao.findAccountByName(targeName);
    		//2.修改两个账户的金额
    		source.setMoney(source.getMoney()-money);//转出账户减钱
    		target.setMoney(target.getMoney()+money);//转入账户加钱
    		//3.更新两个账户
    		accountDao.updateAccount(source);
    		int i=1/0;
    		accountDao.updateAccount(target);
    	}
    
    }
    
    
    package com.zzg.transaction.entity;
    
    import java.io.Serializable;
    
    @SuppressWarnings("serial")
    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 + "]";
    	}
    
    }

演示代码和配置文件

package com.zzg.transaction;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    import com.zzg.transaction.entity.Account;
    import com.zzg.transaction.service.IAccountService;
    
    public class TransactionTest {
    
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		// 1.获取 Spring 容器
    		ApplicationContext ac = new ClassPathXmlApplicationContext("transactionAnnotation.xml");
    		IAccountService service = (IAccountService) ac.getBean("accountService");
    		Account account = service.findAccountById(1);
    		System.out.println(account.toString());
    		
    		service.transfer("张三", "李四", 100f);
    		
    	}
    
    }

**第四 基于 XML 方式进行事务控制,核心步骤说明:**

第一步：配置事务管理器
    
     
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
         
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    第二步：配置事务的通知引用事务管理器
    
    
     <tx:advice id="txAdvice" transaction-manager="transactionManager">
     </tx:advice>
    
    第三步：配置事务的属性
    
     
    <tx:attributes>
         
        <tx:method name="*" read-only="false" propagation="REQUIRED"/>
        <tx:method name="find*" read-only="true" propagation="SUPPORTS"/>
    </tx:attributes>
    
    第四步：配置 AOP 切入点表达式
    
    
    <aop:config>
        
         <aop:pointcut expression="execution(* com.itheima.service.impl.*.*(..))"
            id="pt1"/>
    </aop:config>
    
    第五步：配置切入点表达式和事务通知的对应关系
    
    
     <aop:advisor advice-ref="txAdvice" pointcut-ref="pt1"/>

**第五 基于 注解 方式进行事务控制,核心步骤说明:**

第一步：配置事务管理器并注入数据源
    
     
    <bean id="transactionManager"
    class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    第二步：在业务层使用@Transactional 注解
    
    @Service("accountService")
    @Transactional(readOnly=true,propagation=Propagation.SUPPORTS)
    public class AccountServiceImpl implements IAccountService{
            ******
    }
    
    第三步：在配置文件中开启 spring 对注解事务的支持
    
     
    <tx:annotation-driven transaction-manager="transactionManager"/>

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