qq_25092487-优快云博客

原创 nginx相关

1、nginx安装使用源代码安装2、命令# start service/usr/local/nginx/sbin/nginx# reload config/usr/local/nginx/sbin/nginx -s reload# 其他命令cd /usr/local/nginx/sbin/./nginx ./nginx -s stop./nginx -s quit./nginx -s reload3、自启动# vim /etc/init.d/nginxnginx="/us

2022-01-10 19:17:30 1061

原创 springmvc/RequestParam/RequestBody/feign

springmvc 接口参数类型大致：RequestHeaderRequestParamRequestBodyPathVariablepublic Result createMessage(@RequestBody CreateRequest request)之前body方式传递数据。public Result createMessage(CreateRequest request)默认@RequestParam，每个属性都是一个RequestParam类型参数需要注意的是，

2021-12-30 18:14:36 411

原创 JPA - 杂

JPA配置信息# JPA自动创建数据库，在jdbc-url中增加参数createDatabaseIfNotExist=true&serverTimezone=UTC&useUnicode=true&characterEncoding=utf8&useSSL=false# JPA自动创建数据表spring.jpa.generate-ddl=true# JPA默认将Java驼峰命名的属性使用下划线分隔创建表的字段，使用Physical策略，表明与@Column或者属性

2021-12-22 19:06:14 254

原创 devtools in idea

必须写的<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <optional>true</optional> </dependency></de

2021-12-21 10:05:08 91

原创 jpa属性名到数据表字段名的映射

如果属性与字段名不一致，可以设置@Column的name属性，修改属性到字段的映射默认的@Column的name向字段名映射，将驼峰命名转换为下划线分隔的命名方式如果属性名保持与字段名命名方式一致，修改一下命名转换策略```javaspring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl```...

2021-12-20 18:32:26 1712

转载 redis双写不一致问题

多线程写数据库更新缓存策略：解决办法：延时双删策略先删除缓存再写数据库异步等待一段时间后，再次淘汰缓存。（这里的时间设定主要是保证读请求结束，写请求可以删除读请求遭成的缓存脏数据，需要自行评估确定。）该方案解决了高并发情况下，同时有读请求与写请求时导致的不一致问题。读取速度快，但是可能会出现短时间的脏数据。如果第二次删除也删除失败，则需要添加重试机制保证一定删除成功。————————————————版权声明：本文为优快云博主「qq_28228605」的原创文...

2021-04-12 10:00:24 239

原创 centos下几个常用的设置代理

wget设置代理vim /etc/wgetrcThey will override the value in the environment.https_proxy = http://192.168.10.5:3128/http_proxy = http://192.168.10.5:3128/ftp_proxy = http://192.168.10.5:3128/If you do not want to use proxy at all, set this to off.use_prox

2021-04-09 18:17:00 108

原创 npm安装及设置代理

yum install gcc gcc-c++wget https://cdn.npm.taobao.org/dist/node/v10.14.1/node-v10.14.1-linux-x64.tar.gztar -xzvf node-v10.14.1-linux-x64.tar.gzmv node-v10.14.1-linux-x64 /usr/local/nodevi /etc/profileexport NODE_HOME=/usr/local/nodeexport PATH=PATH:

2021-04-09 18:15:57 929

原创 HotSpot JVM Memory Management（未完待续）

HotSpot JVM Memory ManagementAutomatic Memory ManagementObject AllocationsRoot TracyMarkCollect GarbageCompactAllocations ContinueGenerational Garbage Collection and Memory Spaces in the HotSpot JVMGarbage collector is responsible forMemory

2021-04-09 18:14:30 122

原创 jvm参考资料

参考资料The Java® Virtual Machine Specification-Java SE 14 EditionHotSpot JVM Memory ManagementDissecting Memory ProblemsHotSpot Runtime OverviewJava SE 7 Features and Enhancements

2021-04-09 18:13:56 65

原创 Java 自带命令行工具

Java 自带命令行工具cmd常用参数说明jcmd13892:The following commands are available:Compiler.CodeHeap_AnalyticsCompiler.codecacheCompiler.codelistCompiler.directives_addCompiler.directives_clearCompiler.directives_printCompiler.directives_removeCompiler.queue

2021-04-09 18:13:01 141

原创 java.util.concurrent学习

Queue阻塞队列BlockingQueue由保证有序性class定义说明BlockingQueue单向阻塞队列接口BlockingDeque双向阻塞队列接口TransferQueue参照接口定义ArrayBlockingQueue[ReentrantLock]有界阻塞队列数组实现的LinkedBlockingQueue[ReentrantLock]have higher throughput than array-based queues

2021-04-09 18:11:15 193

原创 docker常用命令

docker pull thczht.com/library/smart-new-api-gateway:2.0.34docker logs -f 7eb50a7813addocker psdocker imagesdocker stop 7eb50a7813addocker run -itd --name ubuntu-test ubuntu /bin/bashdocker run -itd b0459b9a2968 /bin/bashdocker run -e JAVA_OPTS=’-DN

2021-04-09 18:10:06 122

原创 What is klass?

Klass is the internal representation of a Java class (let's say A) & it will hold the basic information about the structure of the class including the bytecode. It will be stored as an object itself. Every object of the class A will have a pointer to .

2021-04-09 11:24:39 71

转载 springboot环境下相同类进行转换出现ClassCastException异常

https://www.jianshu.com/p/e6d5a3969343

2020-08-25 11:24:12 427

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