整体的工程代码跟上一篇日志的工程差不多。
服务类StudentService.java的代码如下:
class="java" name="code">package com.mysrc.service; import java.sql.Date; import java.util.List; import org.springframework.transaction.TransactionStatus; import org.springframework.transaction.support.TransactionCallback; import org.springframework.transaction.support.TransactionCallbackWithoutResult; import org.springframework.transaction.support.TransactionTemplate; import com.mysrc.dao.StudentDao; import com.mysrc.entity.Student; public class StudentService { private StudentDao dao; private TransactionTemplate transactionTemplate; public void setDao(StudentDao dao) { this.dao = dao; } public void setTransactionTemplate(TransactionTemplate transactionTemplate) { this.transactionTemplate = transactionTemplate; } public void doLogic1() { transactionTemplate.execute(new TransactionCallbackWithoutResult() { protected void doInTransactionWithoutResult(TransactionStatus status) { try { doComplexLogic(); } catch (Exception ex) { // 通过调用 TransactionStatus 对象的 setRollbackOnly() 方法来回滚事务。 status.setRollbackOnly(); ex.printStackTrace(); } } }); } public String doLogic2() { return transactionTemplate.execute(new TransactionCallback<String>() { public String doInTransaction(TransactionStatus status) { String result = "success"; try { doComplexLogic(); } catch (Exception e) { status.setRollbackOnly(); e.printStackTrace(); result = "fail"; } return result; } }); } public void doComplexLogic() { // select List<Student> list = dao.getAllStudent(); for (Student student : list) { System.out.println(student); } // update Student student = list.get(0); student.setName("dianping.."); dao.updateStudent(student); System.out.println("did update temporarily..."); // int a = 9 / 0; // 遇到异常 int b = 2; if (b > 1) { throw new CustomRuntimeException(); } // insert student = new Student(); student.setName("hello"); student.setBirth(new Date(354778)); student.setScore(78.9f); dao.addStudent(student); System.out.println("did insert..."); // delete dao.deleteStudent(3); System.out.println("did delete..."); } }
?和上两篇日志不同的是,这儿不仅注入了dao,而且注入了一个transactionTemplate。这里TransactionTemplate模板类使用两种回调接口:TransactionCallback和TransactionCallbackWithoutResult。从字面就可以知道一个是不带返回值的,而另一个可以给出一个返回值。这里用到的transactionTemplate在applicationContext.xml文件中的配置如下:
<?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:p="http://www.springframework.org/schema/p" 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.xsd" xmlns:tx="http://www.springframework.org/schema/tx"> <bean id="basicDataSource" class="org.apache.commons.dbcp.BasicDataSource"> <property name="url" value="jdbc:mysql://127.0.0.1:3306/mytestdb?characterEncoding=utf8" /> <property name="driverClassName" value="com.mysql.jdbc.Driver" /> <property name="username" value="root" /> <property name="password" value="123456" /> <property name="maxActive" value="100" /> <property name="maxIdle" value="30" /> <property name="maxWait" value="1000" /> <property name="validationQuery" value="select 1" /> </bean> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <constructor-arg name="dataSource" ref="basicDataSource"> </constructor-arg> </bean> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager "> <property name="dataSource"> <ref bean="basicDataSource" /> </property> </bean> <bean id="studentDao" class="com.mysrc.dao.StudentDao"> <property name="jdbcTemplate"> <ref bean="jdbcTemplate" /> </property> </bean> <bean id="studentService" class="com.mysrc.service.StudentService"> <property name="dao" ref="studentDao" /> <property name="transactionTemplate" ref="aTransactionTemplate" /> </bean> <bean id="aTransactionTemplate" class="org.springframework.transaction.support.TransactionTemplate"> <property name="transactionManager" ref="transactionManager" /> <property name="propagationBehaviorName" value="PROPAGATION_NESTED" /> <property name="timeout" value="1000" /> <property name="isolationLevelName" value="ISOLATION_READ_UNCOMMITTED" /> </bean> </beans>
?在TransactionTemplate的bean声明中,也可以添加timeout,isolation等配置。
测试类的代码如下:
package com.mysrc.test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.mysrc.service.StudentService; public class MyTester { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext( "applicationContext.xml"); StudentService studentService = (StudentService) context .getBean("studentService"); studentService.doLogic1(); String rs = studentService.doLogic2(); System.out.println(rs); } }
??eclipse工程文件在附件中。。