spring（四）事务管理

原教程： https://www.w3cschool.cn/wkspring/

spring编程式事务管理

• org.springframework.transaction.PlatformTransactionManager 接口（提交或回滚事务）
• TransactionDefinition 接口（定义事务的隔离级别和事务传播行为）
• TransactionStatus 接口（查询事务的状态）
• 使用方式：
  • TransactionDefinition def = new DefaultTransactionDefinition();
  • TransactionStatus status = transactionManager.getTransaction(def);
  • PlatformTransactionManager_Object.commit(status);
  • PlatformTransactionManager_Object.rollback(status);
• beans.xml
  • 配置数据源bean：org.springframework.jdbc.datasource.DriverManagerDataSource（初始化DateSource）
  • 声明TransactionManager bean org.springframework.jdbc.datasource.DataSourceTransactionManager（初始化PlatformTransactionManager）
  • 声明引用上面两个bean的bean

spring声明式事务管理

将事务管理从事务代码中隔离出来，使用注释或者配置XML文件来管理事务。

步骤：

• 使用<tx:advice>创建事务处理的Advice，指定需要作为事务的方法（目标方法）以及transaction-manager
• （这一步可有可无）声明切入点，expression中方法（目标方法）都是事务型的（符合ACID）
• 目标方法在try/catch块中执行
• 发生异常，事务回滚

最重要的是beans.xml文件的配置

// beans.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"
   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-3.0.xsd 
   http://www.springframework.org/schema/tx
   http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
   http://www.springframework.org/schema/aop
   http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">

   <!-- Initialization for data source -->
   <bean id="dataSource" 
      class="org.springframework.jdbc.datasource.DriverManagerDataSource">
      <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
      <property name="url" value="jdbc:mysql://localhost:3306/test"/>
      <property name="username" value="root"/>
      <property name="password" value="usbw"/>
   </bean>

   <tx:advice id="txAdvice"  transaction-manager="transactionManager">
      <tx:attributes>
        <tx:method name="create"/>
      </tx:attributes>
   </tx:advice>

<!--    <aop:config> -->
<!--       <aop:pointcut id="createOperation"  -->
<!--       expression="execution(* com.springjdbc.StudentJDBCTemplate.create(..))"/> -->
<!--       <aop:advisor advice-ref="txAdvice" pointcut-ref="createOperation"/> -->
<!--    </aop:config> -->

   <!-- Initialization for TransactionManager -->
   <bean id="transactionManager"
   class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
      <property name="dataSource"  ref="dataSource" />    
   </bean>

   <!-- Definition for studentJDBCTemplate bean -->
   <bean id="studentJDBCTemplate"  
   class="com.springjdbc.StudentJDBCTemplate">
      <property name="dataSource"  ref="dataSource" />  
   </bean>

</beans>

//StudentDao.java
public interface StudentDao {
    public void setDataSource(DataSource ds);
    public void create(String name, Integer age, Integer marks, Integer year);
    public List<StudentMarks> listStudent();
}

// StudentMarks.java
public class StudentMarks {
    private Integer age;
    private String name;
    private Integer id;
    private Integer marks;
    private Integer year;
    private Integer sid;
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public Integer getMarks() {
        return marks;
    }
    public void setMarks(Integer marks) {
        this.marks = marks;
    }
    public Integer getYear() {
        return year;
    }
    public void setYear(Integer year) {
        this.year = year;
    }
    public Integer getSid() {
        return sid;
    }
    public void setSid(Integer sid) {
        this.sid = sid;
    }
}

// StudentMarksMapper.java
public class StudentMarksMapper implements RowMapper<StudentMarks>{

    @Override
    public StudentMarks mapRow(ResultSet rs, int rowNum) throws SQLException {
        StudentMarks studentMarks = new StudentMarks();
        studentMarks.setId(rs.getInt("id"));
        studentMarks.setName(rs.getString("name"));
        studentMarks.setAge(rs.getInt("age"));
        studentMarks.setSid(rs.getInt("sid"));
        studentMarks.setMarks(rs.getInt("marks"));
        studentMarks.setYear(rs.getInt("year"));
        return studentMarks;
    }
}

// StudentJDBCTemplate.java
public class StudentJDBCTemplate implements StudentDao {
    private JdbcTemplate jdbcTemplateObject;
    public void setDataSource(DataSource ds) {
        this.jdbcTemplateObject = new JdbcTemplate(ds);
    }
    @Override
    public void create(String name, Integer age, Integer marks, Integer year) {
        System.out.println("StudentJDBCTemplate create()");
        try {
            String sql1 = "insert into student(name, age) values(?,?)";
            jdbcTemplateObject.update(sql1, name, age);
            
            String sql3 = "insert into Marks(marks, year) values(?,?)";
            jdbcTemplateObject.update(sql3, marks, year);
            System.out.println("created name = "+name+", age = "+age);
            throw new RuntimeException("simulate Error condition");
        } catch (DataAccessException e) {
            System.out.println("Error in creating record, rolling back");
            throw e;
        }
    }
    @Override
    public List<StudentMarks> listStudent() {
        String sql = "select * from student, marks where student.id=marks.sid";
        List<StudentMarks> studentMarks = jdbcTemplateObject.query(sql, new StudentMarksMapper());
        return studentMarks;
    }
}

// MainApp.java
public class MainApp {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        StudentDao studentJDBCTemplate = (StudentDao) context.getBean("studentJDBCTemplate");
        System.out.println("----------插入记录----------");
        studentJDBCTemplate.create("Zara", 11, 99, 2010);
        studentJDBCTemplate.create("Nuha", 20, 97, 2010);
        System.out.println("----------获取所有记录----------");
        List<StudentMarks> listStudent = studentJDBCTemplate.listStudent();
        for (StudentMarks record : listStudent) {
             System.out.print("ID : " + record.getId() );
             System.out.print(", Name : " + record.getName() );
             System.out.print(", Marks : " + record.getMarks());
             System.out.print(", Year : " + record.getYear());
             System.out.println(", Age : " + record.getAge());
        }
    }
}

运行结果：
----------插入记录----------
StudentJDBCTemplate create()
created name = Zara, age = 11
Exception in thread "main" java.lang.RuntimeException: simulate Error condition