标签:ack collate 判断 rod from font creat tin service
1,问题的描述:
如果一个方法添加了@Transactional注解声明事务,
而方法内又使用了try catch 捕捉异常,
则方法内的异常捕捉会覆盖事务对异常的判断,
从而异致事务失效而不回滚
2, 如何解决?
第一个方法:给@Transactional注解增加:rollbackFor后并手动抛出指定的异常
第二个方法:在捕捉到异常后手动rollback
说明:刘宏缔的架构森林是一个专注架构的博客,地址:https://www.cnblogs.com/architectforest
对应的源码可以访问这里获取: https://github.com/liuhongdi/
说明:作者:刘宏缔 邮箱: 371125307@qq.com
1,项目地址:
https://github.com/liuhongdi/transactional
2,功能说明:
演示了事务方法中捕捉异常时如何使事务回滚
3,项目结构:如图:
1,pom.xml
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!--mybatis begin--> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.2</version> </dependency> <!--mysql begin--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency>
2,application.properties
#mysql spring.datasource.url=jdbc:mysql://localhost:3306/store?characterEncoding=utf8&useSSL=false spring.datasource.username=root spring.datasource.password=password spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver #mybatis mybatis.mapper-locations=classpath:/mapper/*Mapper.xml mybatis.type-aliases-package=com.example.demo.mapper
3,创建数据表goods的sql
CREATE TABLE `goods` ( `goodsId` bigint(11) unsigned NOT NULL AUTO_INCREMENT COMMENT ‘id‘, `goodsName` varchar(500) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL DEFAULT ‘‘ COMMENT ‘name‘, `subject` varchar(200) NOT NULL DEFAULT ‘‘ COMMENT ‘标题‘, `price` decimal(15,2) NOT NULL DEFAULT ‘0.00‘ COMMENT ‘价格‘, `stock` int(11) NOT NULL DEFAULT ‘0‘ COMMENT ‘stock‘, PRIMARY KEY (`goodsId`), UNIQUE KEY `goodsName` (`goodsName`) ) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT=‘商品表‘
注意goodsName字段上有一个唯一的索引,
后面我们会利用它来引发一个duplicate entry 异常
插入一条数据:
INSERT INTO `goods` (`goodsId`, `goodsName`, `subject`, `price`, `stock`) VALUES (3, ‘100分电动牙刷‘, ‘好用到让你爱上刷牙‘, ‘59.00‘, 100);
1,LockController.java
@RestController @RequestMapping("/lock") public class LockController { @Resource OrderService orderService; //购买商品,方法内没有捕捉异常 @GetMapping("/lock") @ResponseBody public String buyLock() { try { int goodsId = 3; orderService.decrementProductStoreLock(goodsId,1); return "success"; } catch (Exception e){ System.out.println("捕捉到了异常 in controller"); e.printStackTrace(); String errMsg = e.getMessage(); return errMsg; } } //购买商品,方法内捕捉异常 @GetMapping("/lockcatch") @ResponseBody public String buyLockCatch() { try { int goodsId = 3; boolean isDecre = orderService.decrementProductStoreLockWithCatch(goodsId,1); if (isDecre) { return "success"; } else { return "false"; } } catch (Exception e){ System.out.println("捕捉到了异常 in controller"); e.printStackTrace(); String errMsg = e.getMessage(); return errMsg; } } //购买商品,方法内捕捉异常 @GetMapping("/lockcatch1") @ResponseBody public String buyLockCatch1() { try { int goodsId = 3; boolean isDecre = orderService.decrementProductStoreLockWithCatch1(goodsId,1); if (isDecre) { return "success"; } else { return "false"; } } catch (Exception e){ System.out.println("捕捉到了异常 in controller"); e.printStackTrace(); String errMsg = e.getMessage(); return errMsg; } } //购买商品,方法内捕捉异常 @GetMapping("/lockcatch2") @ResponseBody public String buyLockCatch2() { try { int goodsId = 3; boolean isDecre = orderService.decrementProductStoreLockWithCatch2(goodsId,1); if (isDecre) { return "success"; } else { return "false"; } } catch (Exception e){ System.out.println("捕捉到了异常 in controller"); e.printStackTrace(); String errMsg = e.getMessage(); return errMsg; } } }
2,GoodsMapper.java
@Repository @Mapper public interface GoodsMapper { Goods selectOneGoods(int goods_id); int updateOneGoodsStock(Goods goodsOne); int insertOneGoods(Goods goodsOne); }
3,Goods.java
public class Goods { //商品id private int goodsId; public int getGoodsId() { return this.goodsId; } public void setGoodsId(int goodsId) { this.goodsId = goodsId; } //商品名字 private String goodsName; public String getGoodsName() { return this.goodsName; } public void setGoodsName(String goodsName) { this.goodsName = goodsName; } //商品库存数 private int stock; public int getStock() { return this.stock; } public void setStock(int stock) { this.stock = stock; } }
4,OrderService.java
public interface OrderService { public boolean decrementProductStoreLock(int goodsId, int buyNum); public boolean decrementProductStoreLockWithCatch(int goodsId, int buyNum); public boolean decrementProductStoreLockWithCatch1(int goodsId, int buyNum); public boolean decrementProductStoreLockWithCatch2(int goodsId, int buyNum); }
5,OrderServiceImpl.java
@Service public class OrderServiceImpl implements OrderService { @Resource private GoodsMapper goodsMapper; /* * * 减库存,供其他方法调用 * */ private boolean decrestock(int goodsId, int buyNum) { Goods goodsOne = goodsMapper.selectOneGoods(goodsId); System.out.println("-------------------------当前库存:"+goodsOne.getStock()+"-------购买数量:"+buyNum); if (goodsOne.getStock() < buyNum || goodsOne.getStock() <= 0) { System.out.println("------------------------fail:buy fail,return"); return false; } int upStock = goodsOne.getStock()-buyNum; goodsOne.setStock(upStock); int upNum = goodsMapper.updateOneGoodsStock(goodsOne); System.out.println("-------------------------success:成交订单数量:"+upNum); int insNum = goodsMapper.insertOneGoods(goodsOne); System.out.println("-------------------------success:ins数量:"+insNum); return true; } //方法内不做try catch捕捉异常,可以正常回滚 @Override @Transactional(isolation = Isolation.REPEATABLE_READ) public boolean decrementProductStoreLock(int goodsId, int buyNum) { return decrestock(goodsId, buyNum); } //异常时不处理,会导致不回滚 @Override @Transactional(rollbackFor={Exception.class}) public boolean decrementProductStoreLockWithCatch(int goodsId, int buyNum) { try { return decrestock(goodsId, buyNum); } catch (Exception e) { System.out.println("捕捉到了异常in service method"); e.printStackTrace(); String errMsg = e.getMessage(); //throw e; return false; } } //异常时手动抛出异常 @Override @Transactional(rollbackFor={Exception.class}) public boolean decrementProductStoreLockWithCatch1(int goodsId, int buyNum) { try { return decrestock(goodsId, buyNum); } catch (Exception e) { System.out.println("捕捉到了异常in service method"); e.printStackTrace(); String errMsg = e.getMessage(); throw e; } } //异常时手动rollback @Override @Transactional(isolation = Isolation.REPEATABLE_READ) public boolean decrementProductStoreLockWithCatch2(int goodsId, int buyNum) { try { return decrestock(goodsId, buyNum); } catch (Exception e) { System.out.println("捕捉到了异常in service method"); e.printStackTrace(); String errMsg = e.getMessage(); //手动rollback TransactionAspectSupport.currentTransactionStatus().setRollbackOnly(); return false; } } }
说明:decrestock这个方法中有两个写操作,分别是:减库存和insert一条商品记录,
后者会引发duplicate entry异常
6,GoodsMapper.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.transactional.demo.mapper.GoodsMapper"> <select id="selectOneGoods" parameterType="int" resultType="com.transactional.demo.pojo.Goods"> select * from goods where goodsId=#{goodsId} </select> <update id="updateOneGoodsStock" parameterType="com.transactional.demo.pojo.Goods"> UPDATE goods SET stock = #{stock} WHERE goodsId = #{goodsId} </update> <insert id="insertOneGoods" parameterType="com.transactional.demo.pojo.Goods" useGeneratedKeys="true" keyProperty="goodsId"> insert into goods(goodsName) values( #{goodsName}) </insert> </mapper>
1,测试正常回滚:访问:
http://127.0.0.1:8080/lock/lock
返回:
### Error updating database. Cause: java.sql.SQLIntegrityConstraintViolationException: Duplicate entry ‘100分电动牙刷‘ for key ‘goodsName‘
### The error may involve com.transactional.demo.mapper.GoodsMapper.insertOneGoods-Inline
### The error occurred while setting parameters
### SQL: insert into goods(goodsName) values( ?)
### Cause: java.sql.SQLIntegrityConstraintViolationException: Duplicate entry ‘100分电动牙刷‘ for key ‘goodsName‘ ;
Duplicate entry ‘100分电动牙刷‘ for key ‘goodsName‘;
nested exception is java.sql.SQLIntegrityConstraintViolationException: Duplicate entry ‘100分电动牙刷‘ for key ‘goodsName‘
查看数据表:
库存未减少,说明正常回滚
查看控制台:
-------------------------当前库存:100-------购买数量:1
-------------------------success:成交订单数量:1
捕捉到了异常 in controller
2,测试事务无效,不能正常回滚:访问:
http://127.0.0.1:8080/lock/lockcatch
返回:
false
查看数据表:
回滚失效
查看控制台:
-------------------------当前库存:100-------购买数量:1
-------------------------success:成交订单数量:1
捕捉到了异常in service method
3,测试捕捉到异常后手动抛出异常引发回滚:
访问:
http://127.0.0.1:8080/lock/lockcatch1
返回:
### Error updating database. Cause: java.sql.SQLIntegrityConstraintViolationException: Duplicate entry ‘100分电动牙刷‘ for key ‘goodsName‘ ### The error may involve com.transactional.demo.mapper.GoodsMapper.insertOneGoods-Inline ### The error occurred while setting parameters ### SQL: insert into goods(goodsName) values( ?) ### Cause: java.sql.SQLIntegrityConstraintViolationException: Duplicate entry ‘100分电动牙刷‘ for key ‘goodsName‘ ; Duplicate entry ‘100分电动牙刷‘ for key ‘goodsName‘; nested exception is java.sql.SQLIntegrityConstraintViolationException: Duplicate entry ‘100分电动牙刷‘ for key ‘goodsName‘
查看数据表:
查看控制台:
-------------------------当前库存:99-------购买数量:1
-------------------------success:成交订单数量:1
捕捉到了异常in service method
...
捕捉到了异常 in controller
...
4,测试捕捉到异常后手动回滚
访问:
http://127.0.0.1:8080/lock/lockcatch2
返回:
false
查看数据表:
查看控制台:
-------------------------当前库存:99-------购买数量:1
-------------------------success:成交订单数量:1
捕捉到了异常in service method
5,大家注意最后两个返回的区别:为什么会不一样?
手动抛出异常后,会被controller捕捉到,所以没有返回success或false,
而是返回了异常的提示信息
. ____ _ __ _ _ /\\ / ___‘_ __ _ _(_)_ __ __ _ \ \ \ ( ( )\___ | ‘_ | ‘_| | ‘_ \/ _` | \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ‘ |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.3.4.RELEASE)
spring boot:方法中使用try...catch导致@Transactional事务无效的解决(spring boot 2.3.4)
标签:ack collate 判断 rod from font creat tin service
原文地址:https://www.cnblogs.com/architectforest/p/13822505.html