<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[蟹蟹肉的博客]]></title><description><![CDATA[小愿望一个个的实现...]]></description><link>https://blog.youkuaiyun.com/F_K999</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; F_K999]]></copyright><item><title><![CDATA[org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a].....]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/102804836</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/102804836</guid><author>F_K999</author><pubDate>Tue, 29 Oct 2019 17:36:50 +0800</pubDate><description><![CDATA[报错：

org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint [null]; nested exception is org.hibernate.exception.ConstraintViolationException: could...]]></description><category></category></item><item><title><![CDATA[org.springframework.orm.jpa.JpaSystemException: No default constructor for entity:  : com.imooc...]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/102793512</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/102793512</guid><author>F_K999</author><pubDate>Tue, 29 Oct 2019 10:06:07 +0800</pubDate><description><![CDATA[报错：

org.springframework.orm.jpa.JpaSystemException: No default constructor for entity: : com.imooc.dataobject.ProductCategory; nested exception is org.hibernate.InstantiationException: No default co...]]></description><category></category></item><item><title><![CDATA[org.springframework.test.context.junit4.SpringJUnit4ClassRunner - SpringJUnit4ClassRunner ...]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/102775279</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/102775279</guid><author>F_K999</author><pubDate>Mon, 28 Oct 2019 09:53:34 +0800</pubDate><description><![CDATA[idea运行的时候出现错误：

org.springframework.test.context.junit4.SpringJUnit4ClassRunner - SpringJUnit4ClassRunner constructor called with [class com.imooc.repository.ProductCategoryRepositoryTest]



解决的方法：

...]]></description><category></category></item><item><title><![CDATA[[Err] 1055 - Expression #1 of ORDER BY clause is not in GROUP BY clause and contains ......]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/102743460</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/102743460</guid><author>F_K999</author><pubDate>Fri, 25 Oct 2019 15:18:44 +0800</pubDate><description><![CDATA[在 Mysql 数据库中执行命令后出现错误提示：

[Err] 1055 - Expression #1 of ORDER BY clause is not in GROUP BY clause and contains nonaggregated column 'information_schema.PROFILING.SEQ' which is not functionally depende...]]></description><category></category></item><item><title><![CDATA[springboot 连接数据库出错：java.sql.SQLException: The server time zone value 'ÖÐ¹ú±ê×¼Ê±¼ä' is .....]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/94582848</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/94582848</guid><author>F_K999</author><pubDate>Wed, 03 Jul 2019 17:54:47 +0800</pubDate><description><![CDATA[springboot连接数据库出现错误：

java.sql.SQLException: The server time zone value 'ÖÐ¹ú±ê×¼Ê±¼ä' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via t...]]></description><category></category></item><item><title><![CDATA[Windows存在两个数据库——XAMPP中的数据库和新下载的数据库（mysql）]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/93898776</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/93898776</guid><author>F_K999</author><pubDate>Fri, 28 Jun 2019 14:38:20 +0800</pubDate><description><![CDATA[前提：Windows已经安装好了XAMPP，且XAMPP中的MySQL再还没下载另一个数据库时能正常启动运行。

现在准备再下载一个MySQL的数据库。

1、首先登录MYSQL官网下载安装包并解压。

https://dev.mysql.com/downloads/mysql/

我这边下载的是mysql-5.7.23-winx64.zip版本的





2、环境配置

2.1、新创建变量：M...]]></description><category></category></item><item><title><![CDATA[mysqld.exe 无法找到入口]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/93859979</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/93859979</guid><author>F_K999</author><pubDate>Thu, 27 Jun 2019 11:29:36 +0800</pubDate><description><![CDATA[双击mysqld.exe出现如下图片



是因为缺少Visual C++ 2013 库，下载安装就可以了。

Visual C++ 2013 库：https://www.microsoft.com/zh-CN/download/details.aspx?id=40784



再次双击mysqld.exe。
...]]></description><category></category></item><item><title><![CDATA[Maven 的下载安装和配置]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/93722376</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/93722376</guid><author>F_K999</author><pubDate>Wed, 26 Jun 2019 11:39:04 +0800</pubDate><description><![CDATA[1、进入官网下载，并解压。



2、配置环境变量

1.1 创建新的变量名：MAVEN_HOME，值是自己下载的对应目录。

1.2 在Path下追加：%MAVEN_HOME%\bin\





3、测试是否安装成功

输入 mvn -v出现以下相关的信息就表示成功了。



4、配置本地仓库

1、先新创建一个新的文件夹作为maven的仓库。maven-repository。



2、修...]]></description><category></category></item><item><title><![CDATA[JDK12 的下载和没有jre的解决及环境配置]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/90230546</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/90230546</guid><author>F_K999</author><pubDate>Wed, 15 May 2019 10:30:06 +0800</pubDate><description><![CDATA[一、下载直接在官网上下载并点击安装即可，步骤省。

jdk12下载中途已经没有跳出窗口下载jre的过程了，需要手动生成jre.



二、没有jre的解决：

1.cmd



2.切换到jdk的安装目录，执行命令：

bin\jlink.exe --module-path jmods --add-modules java.desktop --output jre





三、环境配置：

1....]]></description><category></category></item><item><title><![CDATA[maven --在通过Controller后，return返回json到页面出现乱码]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/89426413</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/89426413</guid><author>F_K999</author><pubDate>Sun, 21 Apr 2019 00:47:49 +0800</pubDate><description><![CDATA[前提：（在windows--Preferences下的该设置的都已经设置成UTF-8了）

return返回json到页面还是出现乱码：





解决：

添加：produces="text/html;charset=UTF-8"



结果：




...]]></description><category></category></item><item><title><![CDATA[maven pom.xml头文件报错：maven pom.xml Multiple annotations found at this line:...]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/89414233</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/89414233</guid><author>F_K999</author><pubDate>Sat, 20 Apr 2019 11:07:10 +0800</pubDate><description><![CDATA[右击项目，点击Build Path，点击Libraries，可以看到有很多jar包出错。







解决：

1、右键项目，选择maven，选择update project



2、除默认选择外，再勾选Force Update of Snapshots/Releases，点击ok，等待maven依赖更新





如果等待依赖的时间太长，可以自行在网上下载对应的jar包，放在本地仓库中。...]]></description><category></category></item><item><title><![CDATA[JS如何输出空格]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/88783588</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/88783588</guid><author>F_K999</author><pubDate>Sun, 24 Mar 2019 22:18:57 +0800</pubDate><description><![CDATA[1. 使用输出html标签&amp;nbsp;来解决

document.write("&amp;nbsp;&amp;nbsp;"+"1"+"&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;"+"23");

2. 使用CSS样式来解决

document.write("&lt;span style='white-space:pre;'&gt;"+" 1   ...]]></description><category></category></item><item><title><![CDATA[ESLint: Too many blank lines at the end of file. Max of 0 allowed. (no-multiple-empty-lines)]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/88653733</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/88653733</guid><author>F_K999</author><pubDate>Tue, 19 Mar 2019 02:02:51 +0800</pubDate><description><![CDATA[在webstorm写.js文件时，出现错误：

ESLint: Too many blank lines at the end of file. Max of 0 allowed. (no-multiple-empty-lines)



解决办法：

安装 ESLint

命令：npm install -g eslint
...]]></description><category></category></item><item><title><![CDATA[Webstorm如何下载插件]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/88588343</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/88588343</guid><author>F_K999</author><pubDate>Sat, 16 Mar 2019 01:51:55 +0800</pubDate><description><![CDATA[以Vue.js为例

1、打开webstorm软件

2、按Ctrl+Alt+S 跳出Setting窗口或如下图打开：



3、输入Plugins



4、输入想要的插件，点击OK


]]></description><category></category></item><item><title><![CDATA[用webstorm搭建vue项目]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/88575263</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/88575263</guid><author>F_K999</author><pubDate>Fri, 15 Mar 2019 16:24:42 +0800</pubDate><description><![CDATA[前提条件：

已下载安装好webstorm 、node.js、git



开始搭建vue项目：



1、安装淘宝镜像（类似于阿里云的maven中央仓库镜像）

安装命令：

npm install -g cnpm --registry=https://registry.npm.taobao.org

验证命令：cnpm -v

2、安装webpack

利用cnpm安装webpack命令...]]></description><category></category></item><item><title><![CDATA[React-- 环境搭建]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/88573684</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/88573684</guid><author>F_K999</author><pubDate>Fri, 15 Mar 2019 14:44:37 +0800</pubDate><description><![CDATA[1.安装node。

去官网（https://nodejs.org/en/download/）下载最新的稳定版本，我安装的版本是6.11.2。（ps：尽量下载稳定版的，因为我刚弄的时候下载的是最新的版本，然后又一次跑一个命令一直卡在那里不动，后来重新安装了以后才好）。下载安装完以后在cmd界面输入node -v可以直接查看版本。



安装node时会自带一个npm的包管理工具，我们可以在命令...]]></description><category></category></item><item><title><![CDATA[npm 安装报错 rollbackFailedOptional verb npm-session 解决办法（One CLI for webpack must be installed....）]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/88564717</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/88564717</guid><author>F_K999</author><pubDate>Fri, 15 Mar 2019 00:44:43 +0800</pubDate><description><![CDATA[当利用cnpm安装webpack命令执行cnpm install webpack -g

语句之后输入webpack -v 的命令出现下图



输入YES时出现下图的显示：

（这个图是从别人那拿来的，忘了截图）



解决：

出现这种问题的原因：

请求超时，建议安装个cnpm的淘宝镜像：

（npm config set registry https://registry.npm.t...]]></description><category></category></item><item><title><![CDATA[eclipse中，service locations 是灰色的，怎么修改]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/85268502</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/85268502</guid><author>F_K999</author><pubDate>Wed, 26 Dec 2018 20:47:34 +0800</pubDate><description><![CDATA[问题：

想在service locations 中修改tomcat，但是双击tomcat后发现service locations是灰色的，无法修改。

解决的办法是：

1、先把tomcat下的项目移除掉

2、然后右击 tomcat 点击 clean

3、再次双击tomcat，就可以看到 service locations 下不是灰色的，可以修改了。...]]></description><category></category></item><item><title><![CDATA[Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements: healt]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/85247710</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/85247710</guid><author>F_K999</author><pubDate>Tue, 25 Dec 2018 14:52:36 +0800</pubDate><description><![CDATA[使用SSH框架的时候：使用注解创建表格时出现错误：

Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements: healt，

是因为在对多对多或者一对多初始化对象的时候接收的类型不对：

错误：



正确：



 

 

【如果接着出现错误：】

mapped...]]></description><category></category></item><item><title><![CDATA[表单textarea中的内容怎么从数据库中显示出来]]></title><link>https://blog.youkuaiyun.com/F_K999/article/details/85238183</link><guid>https://blog.youkuaiyun.com/F_K999/article/details/85238183</guid><author>F_K999</author><pubDate>Mon, 24 Dec 2018 19:49:49 +0800</pubDate><description><![CDATA[需要注意知道的是：

在textarea中是没有value属性的。

解决方法：

如果想把数据库中的内容显示出来可以这样写：



错误的写法：

]]></description><category></category></item></channel></rss>