Spring管理事物应用到实际的项目中--编程式事物

忘是亡心i 2022-08-10 11:44 157阅读 0赞

接着上一篇博客来写。。。

下面来看一下如何将Spring管理事物应用到实际的项目中，为了简化实现，这里只定义最简单的模型对象和不完整的DAO和Service层接口

1、定义项目中的模型对象，这里使用用户模型和用户的地址模型：模型对象一般放在model包里

public class UserModel {
    	private int id;
    	private String user_name;
    	private String password;
    	private AddressModel address;
        省略getter和setter方法

public class AddressModel {
    
    	private int id;
    	private String province;
    	private String city;
    	private String street;
    	private int userid;
    	省略getter和setter方法

2.1、定义DAO层接口    DAO层实现具体的数据访问逻辑，屏蔽对数据访问技术造成的差异

package com.spring.DAO;
    public interface IUserDAO {
    	public KeyHolder save(UserModel user);
    	public int countAll();
    }

package com.spring.DAO;
    public interface IAdressDAO {
    	public KeyHolder save(AddressModel address);
    	public int countAll();
    }

2.2、DAO层实现

package com.spring.DAOImpl;
    public class UserJdbcDAOImpl extends NamedParameterJdbcDaoSupport implements IUserDAO{
    	private final String INSERT_SQL="insert into td(user_name,password)values(:user_name,:password)";
    	private final String COUNT_ALL_SQL="select count(*)from td";
    	@Override
    	public KeyHolder save(UserModel user) {
    		KeyHolder keyHolder=new GeneratedKeyHolder();
    		/**
    		 * SqlParameterSource：可以使用SqlParameterSource实现作为来实现为命名参数设值，
    		 * 默认有MapSqlParameterSource和BeanPropertySqlParameterSource实现；
    		 * MapSqlParameterSource实现非常简单，只是封装了java.util.Map；
    		 * 而BeanPropertySqlParameterSource封装了一个JavaBean对象，通过JavaBean对象属性来决定命名参数的值。
    		 */
    		SqlParameterSource paramSource=new BeanPropertySqlParameterSource(user);
    		/**
    		 * 设置如何获取自增主键值
    		 */
    		getNamedParameterJdbcTemplate().update(INSERT_SQL, paramSource,keyHolder,new String[]{"id"});
    		return keyHolder;
    	}
    	@Override
    	public int countAll() {
    		return getJdbcTemplate().queryForInt(COUNT_ALL_SQL);
    	}
    }

package com.spring.DAOImpl;
    public class AddressJdbcDAOImpl extends NamedParameterJdbcDaoSupport implements IAdressDAO{
    	private final String INSERT_SQL="insert into address(province,city,street,userid) values(:province,:city,:street,:userid)";
    	private final String COUNT_ALL_SQL="select count(*)from address";
    	@Override
    	public int countAll() {
    		return getJdbcTemplate().queryForInt(COUNT_ALL_SQL);
    	}
    	/**
    	 * 这里表示了如何获取主键自增值
    	 */
    	@Override
    	public KeyHolder save(AddressModel address) {
    		KeyHolder keyHolder=new GeneratedKeyHolder();
    		SqlParameterSource paramSource=new BeanPropertySqlParameterSource(address);
    		/**
    		 * 注意下面的参数列表
    		 */
    		getNamedParameterJdbcTemplate().update(INSERT_SQL, paramSource,keyHolder,new String[]{"id"});
    		return keyHolder;
    	}
    }

3.1、定义Service层接口，一般使用IxxxServeice命名，Service类对象的是业务类

package com.spring.Service;
    public interface IUserService {
    	public void save(UserModel user);
    	public int countAll();
    }

package com.spring.Service;
    public interface IAdressService {
    	public void save(AddressModel address);
    	public int countAll();
    }

3.2、定义Service层实现，一般使用“×××ServiceImpl”或“×××Service”命名：

package com.spring.serviceImpl;
    public class UserServiceImpl implements IUserService{
    
    	private IUserDAO userDAO;
    	private IAdressService adressService;
    	public void setAdressService(IAdressService adressService) {
    		this.adressService = adressService;
    	}
    	private PlatformTransactionManager txManager;
    	public IUserDAO getUserDAO() {
    		return userDAO;
    	}
    	public void setUserDAO(IUserDAO userDAO) {
    		this.userDAO = userDAO;
    	}
    	public PlatformTransactionManager getTxManager() {
    		return txManager;
    	}
    	public void setTxManager(PlatformTransactionManager txManager) {
    		this.txManager = txManager;
    	}
    	@Override
    	public void save(final UserModel user) {
    		TransactionTemplate  transactionTemplate=TransactionTemplateUtils.getDefaultTransactionTemplate(txManager);
    		transactionTemplate.execute(new TransactionCallbackWithoutResult(){
    			@Override
    			protected void doInTransactionWithoutResult(TransactionStatus status) {
    				/**
    				 * 如何获取自增主键值
    				 */
    				KeyHolder key=userDAO.save(user);
    				System.out.println(key.getKey().intValue());
    				user.getAddress().setUserid( key.getKey().intValue());
    				System.out.println(user.getAddress().getUserid());
    				System.out.println(user.getAddress().getProvince());
    				adressService.save(user.getAddress());
    			}
    		});
    	}
    	@Override
    	public int countAll() {
    		return userDAO.countAll();
    	}
    }

package com.spring.serviceImpl;
    public class AddressServeiceImpl implements IAdressService{
    
    	private IAdressDAO adressDAO;
    	private PlatformTransactionManager txManager;
    	public void setAdressDAO(IAdressDAO adressDAO) {
    		this.adressDAO = adressDAO;
    	}
    	public void setTxManager(PlatformTransactionManager txManager) {
    		this.txManager = txManager;
    	}
    	@Override
    	public void save(final AddressModel address) {
    		TransactionTemplate transactionTemplate=TransactionTemplateUtils.getDefaultTransactionTemplate(txManager);
    		transactionTemplate.execute(new TransactionCallbackWithoutResult(){
    
    			@Override
    			protected void doInTransactionWithoutResult(TransactionStatus arg0) {
    				KeyHolder keyHolder=adressDAO.save(address);
    				System.out.println(keyHolder.getKey().intValue());
    			}
    		});
    	}
    	@Override
    	public int countAll() {
    		return adressDAO.countAll();
    	}
    }

4、定义TransactionTemplateUtils，用于简化获取TransactionTemplate模板类，工具类一般放在util包中：

package com.spring.util;
    public class TransactionTemplateUtils {
    	public static TransactionTemplate getTransactionTemplate(PlatformTransactionManager txManager,
    			int propagationBehavior,
    			int isolationLevel){
    		TransactionTemplate transactionTemplate=new TransactionTemplate(txManager);
    		transactionTemplate.setPropagationBehavior(propagationBehavior);
    		transactionTemplate.setIsolationLevel(isolationLevel);
    		return transactionTemplate;
    	}
    	/**
    	 * 
    	 * @param txManager
    	 * @return  getDefaultTransactionTemplate用于获取传播行为为PROPAGATION_REQUIRED，隔离级别为ISOLATION_READ_COMMITTED的模板类。
    	 */
    	public static TransactionTemplate getDefaultTransactionTemplate(PlatformTransactionManager txManager){
    		return getTransactionTemplate(txManager,TransactionDefinition.PROPAGATION_REQUIRED,
    				TransactionDefinition.ISOLATION_READ_COMMITTED);
    	}
    }

6、配置文件

<bean id="dataSource"
    		class="org.springframework.jdbc.datasource.DriverManagerDataSource"
    		destroy-method="close">
    		<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"></property>
    		<property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"></property>
    		<property name="username" value="scott"></property>
    		<property name="password" value="123"></property>
    	</bean>
    
    	
    	<bean id="userDAO" class="com.spring.DAOImpl.UserJdbcDAOImpl">
    		<property name="dataSource" ref="dataSource"></property>
    	</bean>
    
    	<bean id="txManager"
    		class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    		<property name="dataSource" ref="dataSource"></property>
    	</bean>
    
    	
    	<bean id="userService" class="com.spring.serviceImpl.UserServiceImpl">
    		<property name="userDAO" ref="userDAO"></property>
    		<property name="txManager" ref="txManager"></property>
    		<property name="adressService" ref="addressService"></property>
    	</bean>
    
    	<bean id="addressDAO" class="com.spring.DAOImpl.AddressJdbcDAOImpl">
    	<property name="dataSource" ref="dataSource"></property>
    	</bean>
    
    	<bean id="addressService" class="com.spring.serviceImpl.AddressServeiceImpl">
    		<property name="adressDAO" ref="addressDAO"></property>
    		<property name="txManager" ref="txManager"></property>
    	</bean>

8、准备测试需要的表创建语句，这里我只创建了address表，因为之前已经创建过用户表在创建表时我实现了主键自增，所以同时要创建序列和引擎

package com.spring.test;
    public class springTransactionTest {
    
    	/**
    	 * 创建address表
    	 */
    	public static final String CREATE_ADDRESS_TABLE_SQL="create table address(id int,province varchar2(40),city varchar2(100),"
    			+ "street varchar2(100) ,userid int,primary key (id))";
    	
    	/**
    	 * address:创建序列
    	 */
    	public static final String CREAT_SQU="create sequence se start with 1"
    			+ "increment by 1 minvalue 1 maxvalue 999999 nocycle nocache";
    	/**
    	 * address:实现主键自增
    	 */
    	public static final String KEY_INCRE_SQL="insert into address(id) values (se.NEXTVAL)";
    	
    	/**
    	 * address:创建引擎
    	 */
    	public static final String TRIGGER_SQL="create  trigger trie before insert on address for each row begin select se.NEXTVAL into :new.id from dual;end;";

9、测试

@Test
    	public void test() {
    		ApplicationContext ctx=new ClassPathXmlApplicationContext("/applicationContext.xml");
    		DataSource dataSource=(DataSource) ctx.getBean("dataSource");
    		JdbcTemplate jdbcTemplate=new JdbcTemplate(dataSource);
    		IUserService userService=(IUserService) ctx.getBean("userService");
    		
    		IAdressService addressService=(IAdressService) ctx.getBean("addressService");
    		/**
    		 * 创建表、序列、主键自增，引擎，之前一直在触发的时候出错
    		 */
    		
    		jdbcTemplate.execute(CREATE_ADDRESS_TABLE_SQL);
    		jdbcTemplate.execute(CREAT_SQU);
    		jdbcTemplate.execute(KEY_INCRE_SQL);
    		jdbcTemplate.execute(TRIGGER_SQL);
    		
    		UserModel user=createDefaultUserModel();
    		userService.save(user);
    	}
    	private  UserModel createDefaultUserModel(){
    		UserModel user=new UserModel();
    		user.setUser_name("mk");
    		user.setPassword("000");
    		
    		AddressModel address=new AddressModel();
    		address.setProvince("zhejiang");
    		address.setCity("jinhua");
    		address.setStreet("hel");
    		user.setAddress(address);
    		return user;
    	}

从Spring容器中获取Service层对象，调用Service层对象持久化对象，大家有没有注意到Spring事务全部在Service层定 义，  
为什么会在Service层定义，而不是Dao层定义呢？这是因为在服务层可能牵扯到业务逻辑，而每个业务逻辑可能调用多个Dao  
层方法，为保证这些 操作的原子性，必须在Service层定义事务。  
  
  
Service层的事物管理相当令人头疼，而且是侵入式的，如何消除这些冗长的代码呢，这就需要spring声明式的事物支持。  
在实现这一节的时候，我碰到的主要问题是创建表时关于引擎的问题，还有就是如何获得user表中的id然后插入到address表  
中，后来我摸索了很久终于知道如何获取自增的主键值了，这了在dao层和service层中一定要搞清楚user表和address中字段  
关系。  
我参考的博客上面还介绍了事物的属性并举例实现，我还没弄太明白，所以没实现。  
  
  
下一篇博客中我将展示以下我的声明式事物的实现