<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[bang2tang2的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/bang2tang2</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; bang2tang2]]></copyright><item><title><![CDATA[前端修改条件，后端无须调整代码，动态拼接查询]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/133816021</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/133816021</guid><author>bang2tang2</author><pubDate>Mon, 16 Oct 2023 18:02:11 +0800</pubDate><description><![CDATA[一、条件对应符号。]]></description><category></category></item><item><title><![CDATA[Spirng Data JPA save方法遇到的坑]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/131390434</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/131390434</guid><author>bang2tang2</author><pubDate>Mon, 26 Jun 2023 09:22:43 +0800</pubDate><description><![CDATA[由于save方法的入参是一个实体对象，如果传入的实体对象的某些属性值为空（null），则最后JPA在更新时会把对应的字段也尝试更新为空（null），而实际上你可能只想更新所更改过的字段，对于空值字段你希望自动忽略不更新。save方法在更新DB时一个最大的特点是：默认每次都会先去查一遍DB，对查出来的DB数据与要保存的数据进行比较，看是否有变化，若有变化，才会将数据持久化至DB（执行数据的update），否则，就不会进行数据的持久化。1、在执行更新操作后，调用flush()方法。]]></description><category></category></item><item><title><![CDATA[记录：mongoTemplate分组删除重复数据，保留一条，及遇到的问题（通过ID查询、删除不到数据）]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/130924558</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/130924558</guid><author>bang2tang2</author><pubDate>Mon, 29 May 2023 11:29:01 +0800</pubDate><description><![CDATA[mongoTemplate分组删除重复数据，保留一条，（通过ID查询、删除不到数据）]]></description><category></category></item><item><title><![CDATA[MongoDb 自动创建索引]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/130923868</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/130923868</guid><author>bang2tang2</author><pubDate>Mon, 29 May 2023 11:06:17 +0800</pubDate><description><![CDATA[springboot集成Mongo没有自动创建索引的问题]]></description><category></category></item><item><title><![CDATA[springboot 加载不到外部config中的配置文件]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/129547872</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/129547872</guid><author>bang2tang2</author><pubDate>Wed, 15 Mar 2023 11:01:38 +0800</pubDate><description><![CDATA[ZIP]]></description><category></category></item><item><title><![CDATA[Linux漏洞修复]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/124242656</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/124242656</guid><author>bang2tang2</author><pubDate>Mon, 18 Apr 2022 10:00:51 +0800</pubDate><description><![CDATA[ICMP timestamp请求响应漏洞：
远程主机会回复ICMP_TIMESTAMP查询并返回它们系统的当前时间。 这可能允许者一些基于时间认证的协议
修复：


sudo firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT 0 -p ICMP --icmp-type timestamp-request -m comment --comment "deny ICMP timestamp" -j DROP
sudo firewall-]]></description><category></category></item><item><title><![CDATA[proxysql，Communications link failure问题]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/119248004</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/119248004</guid><author>bang2tang2</author><pubDate>Fri, 30 Jul 2021 15:38:58 +0800</pubDate><description><![CDATA[最近线上的项目查询经常出现500，查询日志发现出错的原因是数据库链接失效的问题Communications link failure。

项目使用的是阿里巴巴druid连接池+proxysql代理+mysql（mgr集群）。

版本：
druid：1.1.16

proxysql：2.2.0

mysql：8.0.20

1、检查druid链接池的配置，该配置的都配置了。


&lt;bean id="masterDataSource" class="com.alibaba.druid.pool.Druid]]></description><category></category></item><item><title><![CDATA[java解压rar5 兼容rar4]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/119178294</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/119178294</guid><author>bang2tang2</author><pubDate>Wed, 28 Jul 2021 14:15:00 +0800</pubDate><description><![CDATA[针对rar5的，找了好多，这个可以用
]]></description><category></category></item><item><title><![CDATA[ipset黑白名单设置]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/118572552</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/118572552</guid><author>bang2tang2</author><pubDate>Thu, 08 Jul 2021 14:21:14 +0800</pubDate><description><![CDATA[iptables黑/白名单设置（使用ipset 工具）
参考链接：https://www.cnblogs.com/vijayfly/p/7205559.html


ipset create whitelist hash:ip;
ipset create blacklist hash:ip;
添加白名单
ipset add  whitelist 192.168.1.100;
ipset add  whitelist 192.168.1.101;
ipset add  whitelist 192.168.1.]]></description><category></category></item><item><title><![CDATA[linux查看CPU占用]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/118572500</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/118572500</guid><author>bang2tang2</author><pubDate>Thu, 08 Jul 2021 14:17:31 +0800</pubDate><description><![CDATA[1、先用top查看占用cpu的进程id
2、再用ps -ef | grep PID定位具体的进程主体；如是否是tomcat启动的java程序
3、用ps -mp pid -o THREAD,tid,time打印出该进程下的线程占用cpu情况
4、其次将需要的线程ID转换为16进制格式：
 printf "%x\n" tid
5、最后打印线程的堆栈信息：
 jstack pid |grep tid -A 30


...]]></description><category></category></item><item><title><![CDATA[使用spring的类 获取包下面的@Table实体类]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/118545718</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/118545718</guid><author>bang2tang2</author><pubDate>Wed, 07 Jul 2021 14:20:34 +0800</pubDate><description><![CDATA[import java.io.IOException;
import java.lang.annotation.Annotation;

import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternRes.]]></description><category></category></item><item><title><![CDATA[根据JPA EntityManager获取实体类与表的映射关系]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/118543196</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/118543196</guid><author>bang2tang2</author><pubDate>Wed, 07 Jul 2021 11:29:04 +0800</pubDate><description><![CDATA[import java.beans.PropertyDescriptor;
import java.util.Map;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceContext;

import org.hibernate.metamodel.internal.MetamodelImpl;
import ]]></description><category></category></item><item><title><![CDATA[导入数据库文件，选择表导入]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/115793821</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/115793821</guid><author>bang2tang2</author><pubDate>Sat, 17 Apr 2021 13:27:40 +0800</pubDate><description><![CDATA[法1：perlextract_sql.pl -t mytable -r mydumpfile &gt; mytable.sql
法2：cat test1db.sql | sed -n '/Table structure for table .test1./,/Table structure for table .test2./p'&gt;/tmp/xxx.sql  ----打印test1与test2之间的内容
法3：awk '/Table structure for table .test1./,/...]]></description><category></category></item><item><title><![CDATA[JDK7发送https请求时使用TLSv1.2]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/108139604</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/108139604</guid><author>bang2tang2</author><pubDate>Fri, 21 Aug 2020 09:07:34 +0800</pubDate><description><![CDATA[项目场景：java发送https请求时使用TLSv1.2提示：这里简述项目相关背景：
例如：项目场景：示例:通过蓝牙芯片(HC-05)与手机 APP 通信，每隔 5s 传输一批传感器数据(不是很大)

问题描述：使用JDK1.7，发送https请求报错：


javax.net.ssl.SSLException: Received fatal alert: protocol_version

或者


javax.net.ssl.SSLException: Received fatal alert: int]]></description><category></category></item><item><title><![CDATA[小微商户进件-java示例]]></title><link>https://blog.youkuaiyun.com/bang2tang2/article/details/102604205</link><guid>https://blog.youkuaiyun.com/bang2tang2/article/details/102604205</guid><author>bang2tang2</author><pubDate>Thu, 17 Oct 2019 13:38:56 +0800</pubDate><description><![CDATA[使用swing写的一个小工具

jdk1.8，使用的jar包



主类ApplymentMicroSubmit.java

其他相关的java文件去下载吧，项目资源链接压缩包：

https://github.com/daiguobang/weixin/raw/master/WeixinPay.rar


package com.bang.test;

import java.awt.Color...]]></description><category></category></item></channel></rss>