Spring(十五)之声明式事务

声明式事务管理方法允许你在配置的帮助下而不是源代码硬编程来管理事务。这意味着你可以将事务管理从事务代码中隔离出来。你可以只使用注释或基于配置的 XML 来管理事务。 bean 配置会指定事务型方法。下面是与声明式事务相关的步骤：

• 我们使用标签，它创建一个事务处理的建议，同时，我们定义一个匹配所有方法的切入点，我们希望这些方法是事务型的并且会引用事务型的建议。

• 如果在事务型配置中包含了一个方法的名称，那么创建的建议在调用方法之前就会在事务中开始进行。

• 目标方法会在 try / catch 块中执行。

• 如果方法正常结束，AOP 建议会成功的提交事务，否则它执行回滚操作。

1.选择对应的数据库，执行数据库脚本

CREATE TABLE Student(
   ID   INT NOT NULL AUTO_INCREMENT,
   NAME VARCHAR(20) NOT NULL,
   AGE  INT NOT NULL,
   PRIMARY KEY (ID)
);

CREATE TABLE Marks(
   SID INT NOT NULL,
   MARKS  INT NOT NULL,
   YEAR   INT NOT NULL
);

2.编写对应的实体

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

3.编写对应的DAO

package com.tutorialspoint;
import java.util.List;
import javax.sql.DataSource;
public interface StudentDAO {
   /** 
    * This is the method to be used to initialize
    * database resources ie. connection.
    */
   public void setDataSource(DataSource ds);
   /** 
    * This is the method to be used to create
    * a record in the Student and Marks tables.
    */
   public void create(String name, Integer age, Integer marks, Integer year);
   /** 
    * This is the method to be used to list down
    * all the records from the Student and Marks tables.
    */
   public List<StudentMarks> listStudents();
}

4.编写StudentMarksMapper

package com.tutorialspoint;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.springframework.jdbc.core.RowMapper;
public class StudentMarksMapper implements RowMapper<StudentMarks> {
   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;
   }
}

5.编写StudentJDBCTemplate.java

package com.tutorialspoint;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
public class StudentJDBCTemplate implements StudentDAO{
   private JdbcTemplate jdbcTemplateObject;
   public void setDataSource(DataSource dataSource) {
      this.jdbcTemplateObject = new JdbcTemplate(dataSource);
   }
   public void create(String name, Integer age, Integer marks, Integer year){
      try {
         String SQL1 = "insert into Student (name, age) values (?, ?)";
         jdbcTemplateObject.update( SQL1, name, age);
         // Get the latest student id to be used in Marks table
         String SQL2 = "select max(id) from Student";
         int sid = jdbcTemplateObject.queryForInt( SQL2 );
         String SQL3 = "insert into Marks(sid, marks, year) " + 
                       "values (?, ?, ?)";
         jdbcTemplateObject.update( SQL3, sid, marks, year);
         System.out.println("Created Name = " + name + ", Age = " + age);
         // to simulate the exception.
         throw new RuntimeException("simulate Error condition") ;
      } catch (DataAccessException e) {
         System.out.println("Error in creating record, rolling back");
         throw e;
      }
   }
   public List<StudentMarks> listStudents() {
      String SQL = "select * from Student, Marks where Student.id=Marks.sid";
      List <StudentMarks> studentMarks=jdbcTemplateObject.query(SQL, 
      new StudentMarksMapper());
      return studentMarks;
   }
}

6.编写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="1234"/>
   </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.tutorialspoint.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.tutorialspoint.StudentJDBCTemplate">
      <property name="dataSource"  ref="dataSource" />  
   </bean>

</beans>

7.编写MainApp.java并运行对应的main方法

package com.tutorialspoint;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainApp {
   public static void main(String[] args) {
      ApplicationContext context = 
             new ClassPathXmlApplicationContext("Beans.xml");
      StudentDAO studentJDBCTemplate = 
      (StudentDAO)context.getBean("studentJDBCTemplate");     
      System.out.println("------Records creation--------" );
      studentJDBCTemplate.create("Zara", 11, 99, 2010);
      studentJDBCTemplate.create("Nuha", 20, 97, 2010);
      studentJDBCTemplate.create("Ayan", 25, 100, 2011);
      System.out.println("------Listing all the records--------" );
      List<StudentMarks> studentMarks = studentJDBCTemplate.listStudents();
      for (StudentMarks record : studentMarks) {
         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());
      }
   }
}

最后结果为这样的表示事务起作用: