基於ReentrantLock鎖解決超賣問題

@service

@slf4j
public
class
orderservice
//商品當前庫存
integer currentcount = product.
getcount()
;            system.out.
println
(thread.
currentthread()
.getname()
+"庫存數："
+currentcount)
;//校驗庫存
if(purchaseproductnum > currentcount)
// 增量更新庫存
updateproductcount
(purchaseproductnum,
"***"
,new
date()
,product.
getid()
);platformtransactionmanager.
commit
(transaction1);}
finally
transactionstatus transaction = platformtransactionmanager.
gettransaction
(transactiondefinition)
;        order order =
neworder()
;        order.
setorderamount
(product.
getprice()
.multiply
(new
bigdecimal
(purchaseproductnum)))
;        order.
setorderstatus(1
);//待處理
order.
setreceivername
("***");
order.
setreceivermobile
("13311112222");
order.
setcreatetime
(new
date()
);order.
setcreateuser
("***");
order.
setupdatetime
(new
date()
);order.
setupdateuser
("***");
insertselective
(order)
;        orderitem orderitem =
neworderitem()
;        orderitem.
setorderid
(order.
getid()
);orderitem.
setproductid
(product.
getid()
);orderitem.
setpurchaseprice
(product.
getprice()
);orderitem.
setpurchasenum
(purchaseproductnum)
;        orderitem.
setcreateuser
("***");
orderitem.
setcreatetime
(new
date()
);orderitem.
setupdatetime
(new
date()
);orderitem.
setupdateuser
("***");
insertselective
(orderitem)
;// 手動提交事務
platformtransactionmanager.
commit
(transaction)
;return order.
getid()
;}}

在該鎖塊中需要使用try…finally…確保異常時，可以呼叫 lock.unlock();，使鎖能夠被釋放。

然後再下面寫訂單的操作也需要開啟乙個新的事務。

@runwith

(springrunner.
class
)@springboottest
public
class
catch
(exception e)
finally})
;}cdl.
await()
;        es.
shutdown()
;}}

在**最後使用cdl.await();等待所有執行緒執行完畢，才將執行緒池關閉。

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