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403 views

1 answer

我在学习一个秒杀项目，课程提到队列泄洪的技术我的理解是为了避免请求数过大而冲垮系统，通过一个线程池来减缓过大的流量 //封装下单请求 @RequestMapping(value = "/createorder",method = {RequestMethod. ... 一个请求里通过线程池来新建线程，处理一个请求的后续步骤？这样能达到限制请求数的效果吗？...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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582 views

1 answer

请问如何优雅的判断数组存在和数组长度

比如说后端接口返回了一个数组类型数据前端要判断 (json.array && json.array.length) {} 更极端点可能要判断下类型想知道有没有什么办法可以比较优雅的解决. 使用的技术栈有Vue TS Lodash...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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546 views

1 answer

win10应用商店里安装的ubantu20.04LTS为什么没有界面

如题，安装完就是命令行，没有界面是不是哪里出了错还是要设置什么？...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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537 views

1 answer

图片能进行下载，但放到html的img标签中就无法展示出来

放到前端后：什么原因？...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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577 views

1 answer

block 在执行的过程中会被释放吗

假设block被a拥有，现在block执行，还没执行完，a释放了，此时会向block发送release消息吧？...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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237 views

1 answer

python - Find relevant rows falling under a date range in Pandas Dataframe and do some aggregations for these rows

I have 2 Pandas dataframe as below: A = pd.DataFrame({'UserId':['U1','U1','U1','U2','U2','U3'],'Start_Week':[' ... has large number of rows. Is there a quick way to get this done ?...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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587 views

1 answer

windows community toolkit - Grouping data in UWP DataGrid

I am trying to display Information objects grouped by Context property with in the UWP DataGrid using the code below. ... }"/> </controls1:DataGrid.Columns> </controls1:DataGrid>...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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1.8k views

1 answer

rest - How do i solve this problem java.lang.NoClassDefFoundError: sun/security/ssl/HandshakeStateManager?

I'm currently working on a webservice using Netbeans 11.3 on a local Glassfish-server version 5.1.0 JDK/JRE version ... isn't working or do you need any further information? Thanks...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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490 views

1 answer

后端指给我返回了图片的cdn地址，前端可以下载成zip文件吗？

感觉一头雾水啊.地址是我给他的，最多三个地址链接中间以逗号分隔...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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613 views

1 answer

vue watch一个对象，同个值触发了2次，为什么

A <A :params={keyword:''}></A> B prop: { params: Object } watch: { params: { immediate: true, deep: true, handler (new, old) { ... // 触发2次 new:{keyword:''} old: {keyword:''} } }, }...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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574 views

1 answer

TypeScript类型检测不通过,我在写一个选择排序可以传入number，string, 和自定义的Comparable？

codesandbox链接 interface Comparable<T> { compareTo(that: T): number; equals(that: T): boolean; } function selectionSort<E extends ... ; selectionSort<string>(["1", "2", "3"]);...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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113 views

1 answer

js中多个时间，怎么取最小值

['2020-9-1','2020-9-2','2020-9-3'] 怎么取最小的时间...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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291 views

1 answer

element table 中选定某个单元格下方的所有列

element table 中选定某个单元格下方的所有列添加背景色，类似excel中选中某列后添加此列的背景色。目前已经获取到了单元的行列值，怎么选中下方的所有列添加背景色。...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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228 views

1 answer

How to keep matplotlib grid constrained while drawing outside of the grid?

I'm trying to draw the following image in matplotlib: I don't care about the red dot or yellow circle for now. ... the numbers. Any tips to get this working would be appreciated!...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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444 views

1 answer

关于js正则匹配问题

let str = '<span>我是小s</span><span class="show">s</span>' 不匹配标签里的s和类名为show的标签内容s？结果：只找出“我是小s”中的“s”...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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407 views

1 answer

多表联合查询优化

explain select SQL_CALC_FOUND_ROWS * from task a,user b ,task_project c,task_platform d where a.user_id = b.id and a.project_id = c.id and ... 像出在 c.platform_id = d.id 与a表无关联求优化 ...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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252 views

1 answer

ThinkPHP5.1 group,page和count一起使用的问题

sql语句简略 $sql = User::alias()->leftjoin()->field()->where(); $count = $sql->count(); $sql = $sql->order()->group()->page()->select(); return ... 返回的条数是要分组后的条数而不是分组前的条数大佬们，这个要怎么解决？...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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281 views

1 answer

process - java-processing floating point rounding error, how to keep radians rational

I have modified this arcball class so that every call to arcball.rollforward(PI/180); rotates a matrix 1 degree. I ... edit this later to work with rotations other then 1 degree }...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

696 views

1 answer

angular - ESLint - Only Allow Absolute Import Paths Not Relative

I'm working in an Angular 11 project. A lot of the imports in this project are using a relative path or an ... prevent any type of relative paths? To only allow absolute paths?...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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157 views

1 answer

Powershell - Find and Replace and show work

I have written this script to find "Procedure division" and replace it with a null value. It seems to work, so that's a good ... {$_ -replace "$old", "$new"}) | Set-Content $_ }...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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192 views

1 answer

placeholder样式设置

使用element的日期选择框做了一个组件，现在每次点击后input显示的是默认值，而不是v-model值，但是默认值的样式是浅色的，应该怎么去设置默认值的样式代码如下 <el-date- ... 值添加就没有效果了 input:-ms-input-placeholder { color: green !important; } 应该怎么去设置...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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973 views

1 answer

https - Change quarkus secure port for insecure-requests=redirect

I have configured quarkus like this: quarkus.http.host=localhost quarkus.http.port=80 quarkus.http.insecure-requests=redirect ... behaviour to be able to actually point to :443?...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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270 views

1 answer

class - Python dict unpacking operator not unpacking string in constructor

I am creating a small app using socketio in python on server side and JS on client side. For one of my ... Java / JS background. Any suggestion would be appreciated. Thank you...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

378 views

1 answer

reactjs - React-beautiful-dnd flat data structure to nested

I am having a list of layers (sort of like in photoshop) and I need the layers to be able to combine and ... structure. Here is my simplified code https://codesandbox.io/s/282le...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

412 views

1 answer

vue获取的接口，包含的图片，怎么压缩

用vue调接口，图片填充页面，图片太大，反应慢，怎么压缩...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

493 views

1 answer

中文关键词如何与pdf文本进行模糊匹配？

我现在有一个excel表里面包含了需要匹配的关键词，如下现在我拥有若干pdf文档，想实现寻找pdf中是否包含该关键词并计数，实现结果如下：现在面临的问题是，因为这是精确匹配，导致很多关键词实际在pdf文档中出现但并不会被记录比如关键词 ... 联系电话】在类似情况中，匹配无法进行想请问各位大神，在匹配过程中有办法进行一定程度的模糊匹配吗？十分感谢 ...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

757 views

1 answer

database - Update a double type column with NULL value in mysql

I have the following table: IDCode(bigint(20)) lng(double) 0000 NULL NULL NULL 0000 NULL 0000 NULL NULL NULL 0000 NULL...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

456 views

1 answer

react 使用const定义html标签报错

使用 create-react-app 创建的项目，渲染大概是在index.js中import App.js，然后在index.js中最终render 而App.js最终会export default App; 要求这个App必须是String/class/function ... ) } 请问为什么不能这么用？是一般都不这么用吗？还是有什么用法区分？...

asked Jan 27, 2021 in Technique[技术] by 深蓝 (71.8m points)

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