Posts

Hugo 使用指南 适用版本：Hugo v0.168.0（Extended）。命令以 macOS/Linux 的 shell 为例。根据 Hugo 官方文档整理，主题私有配置以实际主题仓库为准。 1. 安装与版本检查 macOS（Homebrew）： brew install hugo hugo version hugo env Linux 可使用对应发行版软件包或 Hugo 官方发布的二进制文件。使用 SCSS/Sass 或某些主题资产管道时，需要确认安装版本包含 Extended 功能。 2. 创建项目 hugo new project myblog cd myblog git init 典型目录结构： myblog/ ├── archetypes/ # 新文章模板 ├── assets/ # 需通过资源管道处理的资源 ├── content/ # Markdown 内容 ├── data/ # 数据文件 ├── i18n/ # 主题界面翻译 ├── layouts/ # 自定义模板，可覆盖主题模板 ├── static/ # 原样复制到网站根路径 ├── themes/ # 本地主题或 Git 子模块 ├── hugo.toml # 网站配置（也可使用 YAML 等格式） └── public/ # 构建产物（运行 hugo 后生成） Hugo 本体不附带完整博客外观。若没有可用主题或自定义布局，可能出现 found no layout file for "html" 的警告。 ...

中国秸秆禁烧政策的历史，实际上是中国农业现代化、农村能源转型、环境治理和基层行政管理方式演变的一个缩影。 最关键的历史结论是：中国并非自古存在大规模秸秆焚烧问题，也不是近年来才开始禁止烧秸秆。现代秸秆禁烧制度在20世纪90年代逐步建立，1999年形成全国性的管理规定，2008年前后明显强化，2013年以后进一步纳入大气污染防治体系。 更值得研究的，是政策治理目标与执行方式之间的变化： 最初的重点是公共安全。 尤其是机场、铁路、公路附近的焚烧风险，同时兼顾大气污染。 后来逐渐转向区域空气质量管理。 秸秆焚烧与城市雾霾、PM2.5治理建立了更紧密的政策联系。 再后来出现基层执行范围扩大和管理方式强化的问题。 一些地方采取全面禁烧、网格巡查和责任追究，导致政策成本与农民生产需求之间的矛盾。 政策争论的核心不是焚烧是否产生污染，而是应当禁止到什么程度，以及由谁承担处理秸秆的经济成本。 一、历史时间线：秸秆禁烧如何一步步形成 20世纪80年代以前 秸秆是有使用价值的农业资源 主要用于烧饭取暖、牲畜饲料、垫圈积肥、堆肥和建材。露天焚烧存在，但大量秸秆并非没有用途。 1980年代末—1990年代 大规模集中焚烧成为社会问题 农业机械化、农村生活燃料转型、粮食增产及农业劳动力转移，使部分地区秸秆集中剩余，焚烧逐渐成为快速清田的方式。 1999—2000年 全国性禁烧管理制度确立 1999年六部门发布《秸秆禁烧和综合利用管理办法》；2000年修订《大气污染防治法》，明确特定区域的秸秆露天焚烧禁令。 2008年 奥运空气质量保障推动强化禁烧 京津冀及周边多个省份实施重点时段严格禁烧，城市及重点区域管控范围扩大。 2013—2017年 与PM2.5及大气污染防治绑定 大气污染防治行动全面推进。2015年修订《大气污染防治法》，规定由省级人民政府划定禁烧区域，并明确相关法律责任。 2018年至今 基层精细化监管与政策争议并存 网格监管、卫星火点监测及秸秆综合利用持续推进，部分地区也探索分区、分时段的焚烧管理。 上面的阶段划分依据国家层面的重要政策节点，而非认为每一年全国都同步改变。 二、1949—1980年代：为什么过去农民很少需要大规模集中烧秸秆？ 要解释今天的禁烧政策，必须先理解一个历史变化： 秸秆从过去的生产生活资源，逐渐变成了部分地区需要付费处理的农业副产物。 1. 传统农村社会有较完整的秸秆利用体系 过去的小农经济中，秸秆具有多种实际用途。 用途 农村的典型做法 生活燃料 使用麦秸、稻草、玉米秆烧饭取暖 牲畜饲料 秸秆切碎后喂牛、羊等反刍动物 农业肥料 堆肥、沤肥、垫圈积肥、直接还田 生活材料 编织草席、制作草绳、屋顶覆盖 农业辅助 覆盖地面、保墒、防止部分土壤侵蚀 这并不意味着过去不存在焚烧。农民同样会焚烧残茬、杂草，或通过草木灰补充部分矿质养分。 ...

2008年的奥运保障是全面禁烧的重要先例，江苏2009年已提出全域禁烧目标。2013年以后，卫星火点、绩效考核与财政奖补共同改变了政策的执行逻辑。

阅读前提：了解国内外云服务（如阿里云、Amazon Web Services），并有一定的使用经验 注册 注册一个微软账户即可，具体步骤可以参考知乎的这篇文章（如何白嫖微软Azure12个月及避坑指南 - 知乎 (zhihu.com)）， 注意：这篇文章写了有很久了，azure的策略可能已经更改，由此可能产生费用，大家实践的时候一定要看清收费策略，或者提前咨询客服，避免不必要的损失。 Azure服务 以下是常用的azure服务： 以下表格是Azure、阿里云和AWS的云服务的对应关系 Azure 阿里云 AWS 备注 订阅（Subscriptions） 资源组（Resource groups） 资源组 虚拟机（Virtual machine） 云服务器ECS EC2 磁盘（Disk） 云盘 卷（Volume） 虚拟网络（Virtual network） 专有网络 VPC 网络接口（Network Interface） 交换机 网络接口（Network interface） 网络安全组（Network security group） 安全组 安全组（Security Group） 公共 IP 地址（Public IP address） 公网IP 公有 IPv4 /IPv6地址（Public IPv4/IPv6 address） SSH 密钥（SSH key） 密钥对 密钥对（Key Pair） 虚拟机 创建 基本 ...

# Debian/Ubuntu使用Nexus的私有镜像源 以Debian11为例 修改**/etc/apt/source.list** vim /etc/apt/source.list # deb cdrom:[Debian GNU/Linux 11.2.0 _Bullseye_ - Official amd64 DVD Binary-1 20211218-11:13]/ bullseye contrib main #deb cdrom:[Debian GNU/Linux 11.2.0 _Bullseye_ - Official amd64 DVD Binary-1 20211218-11:13]/ bullseye contrib main deb http://deb.debian.org/debian/ bullseye main deb-src http://deb.debian.org/debian/ bullseye main deb http://security.debian.org/debian-security bullseye-security main contrib deb-src http://security.debian.org/debian-security bullseye-security main contrib # bullseye-updates, to get updates before a point release is made; # see https://www.debian.org/doc/manuals/debian-reference/ch02.en.html#_updates_and_backports deb http://deb.debian.org/debian/ bullseye-updates main contrib deb-src http://deb.debian.org/debian/ bullseye-updates main contrib 把其中的地址替换成你的私有镜像源地址 # deb cdrom:[Debian GNU/Linux 11.2.0 _Bullseye_ - Official amd64 DVD Binary-1 20211218-11:13]/ bullseye contrib main #deb cdrom:[Debian GNU/Linux 11.2.0 _Bullseye_ - Official amd64 DVD Binary-1 20211218-11:13]/ bullseye contrib main deb http://mirror.nfools.org:8081/repository/debian-bullseye/ bullseye main deb-src http://mirror.nfools.org:8081/repository/debian-bullseye/ bullseye main deb http://security.debian.org/debian-security bullseye-security main contrib deb-src http://security.debian.org/debian-security bullseye-security main contrib # bullseye-updates, to get updates before a point release is made; # see https://www.debian.org/doc/manuals/debian-reference/ch02.en.html#_updates_and_backports deb http://deb.debian.org/debian/ bullseye-updates main contrib deb-src http://deb.debian.org/debian/ bullseye-updates main contrib 保存并退出 创建**/etc/apt/auth.conf.d/nexus.local.intranet.conf**（如果你的仓库允许匿名访问，则忽略这一步） vim /etc/apt/auth.conf.d/nexus.local.intranet.conf 配置你的镜像源地址、登录名和密码 machine http://mirror.nfools.org:8081/ login public password public 保存并退出 更新apt apt update ...

假如你要使用**if**语句判断**Query**类的成员变量**in**是否为**null**，你可能会这么写： ``````（错误） 正确的做法是把Query类的in变量名改成其它名字，比如改成contains <if test="null != query.contains"></if>（正确）

1.在套件中心停用Gitlab。 2.打开docker，右键编辑synology_gitlab，在端口设置中将本地端口44333（自定义）， 映射到容器端口443，然后在环境变量中新增GITLAB_HTTPS true 完成以上步骤后，重启Gitlab，就可以在浏览器上使用https访问Gitlab了。 但是当使用克隆代码时，仍然是使用原来的端口。 3.在环境变量中修改GITLAB_PORT的值为44333（自定义） 然后重启Gitlab就完事了。

# MySQL8.0主从同步 参考：https://www.cnblogs.com/kylinlin/p/5258719.html 一、 主数据库 1.修改配置文件 vim /etc/mysql/mysql.conf.d/mysqld.cnf [mysqld] log-bin=mysql-bin server-id=1 2.锁表 mysql > flush tables with read lock; 3.备份 mysqldump -u root -p 'root' -S /var/run/mysqld/mysqld.sock kpc | gzip > /tmp/mysql_bak.$(date +%F).sql.gz 4.创建用户并授权 CREATE USER 'rep'@'%' IDENTIFIED WITH mysql_native_password BY 'rep'; GRANT REPLICATION SLAVE ON *.* TO 'rep'@'%'; 5.记录信息 mysql > show master status; 6.重启 sudo systemctl restart mysql 二、从数据库 1.修改配置文件 vim /etc/mysql/mysql.conf.d/mysqld.cnf [server-id != 1](# 1.修改配置文件) [mysqld] server-id=2 2.配置Master [MASTER_USER](# 4.创建用户) [MASTER_PASSWORD](# 4.创建用户) [MASTER_LOG_FILE](# 5.记录信息) [MASTER_LOG_POS](# 5.记录信息) mysql> CHANGE MASTER TO -> MASTER_HOST='master_host_name', -> MASTER_USER='rep', -> MASTER_PASSWORD='rep', -> MASTER_LOG_FILE='mysql-bin.000001', -> MASTER_LOG_POS=156 3.运行 mysql > start slave;

我打算把**Spring Cloud Alibaba**升级个版本，看看有什么新特性，结果升级后死活启动不了。 事情是这样的，跟往常一样，我先去Spring官网找到Spring Cloud Alibaba的最新的版本号，如下图所示： 可以看到最新的版本是2021.0.1.0 我默默记下这个版本号… 然后点了右上角的那只章鱼猫 在Wiki里找到版本说明，如下图所示： 现在我知道了Spring Cloud Alibaba Version、Spring Cloud Version和Spring Boot Version三者版本对应关系了！ 我再次回到Spring官网，然后打开Spring Cloud Alibaba的Reference，根据文档，一顿操作。 其实大概就只有三步： 添加依赖 <!--在父工程添加以下依赖--> <properties> <spring.cloud.version>2021.0.1</spring.cloud.version> <spring-boot-dependencies.version>2.6.3</spring-boot-dependencies.version> <com.alibaba.cloud.spring-cloud-alibaba-dependencies.version>2021.0.1.0 </com.alibaba.cloud.spring-cloud-alibaba-dependencies.version> </properties> <dependencyManagement> <dependencies> <!--官网里使用spring-boot-starter-parent作为父工程而没有导入这条依赖，实际作用相同--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>${spring-boot-dependencies.version}</version> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${spring.cloud.version}</version> <type>pom</type> <scope>import</scope> </dependency> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-alibaba-dependencies</artifactId> <version>${com.alibaba.cloud.spring-cloud-alibaba-dependencies.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <!--在module中添加以下依赖--> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId> </dependency> 配置yaml spring: cloud: nacos: discovery: server-addr: 127.0.0.1:8848 在主类上添加**@EnableDiscoveryClient**注解 激动的心，颤抖的手，点击运行！（提前启动好了Nacos） 2022-09-05 00:04:32.047 INFO 37828 --- [ restartedMain] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2022-09-05 00:04:32.047 INFO 37828 --- [ restartedMain] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.56] 2022-09-05 00:04:32.109 INFO 37828 --- [ restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2022-09-05 00:04:32.109 INFO 37828 --- [ restartedMain] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1320 ms 2022-09-05 00:04:32.504 WARN 37828 --- [ restartedMain] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerAdapter' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter]: Factory method 'requestMappingHandlerAdapter' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'messageConverters' defined in class path resource [org/springframework/boot/autoconfigure/http/HttpMessageConvertersAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.http.HttpMessageConverters]: Factory method 'messageConverters' threw exception; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mappingJackson2HttpMessageConverter' defined in class path resource [org/springframework/boot/autoconfigure/http/JacksonHttpMessageConvertersConfiguration$MappingJackson2HttpMessageConverterConfiguration.class]: Unsatisfied dependency expressed through method 'mappingJackson2HttpMessageConverter' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jacksonObjectMapper' defined in class path resource [org/springframework/boot/autoconfigure/jackson/JacksonAutoConfiguration$JacksonObjectMapperConfiguration.class]: Post-processing of merged bean definition failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [com.fasterxml.jackson.databind.ObjectMapper] from ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@2437c6dc] 2022-09-05 00:04:32.507 INFO 37828 --- [ restartedMain] o.apache.catalina.core.StandardService : Stopping service [Tomcat] 2022-09-05 00:04:32.523 INFO 37828 --- [ restartedMain] ConditionEvaluationReportLoggingListener : Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled. 2022-09-05 00:04:32.551 ERROR 37828 --- [ restartedMain] o.s.boot.SpringApplication : Application run failed org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerAdapter' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter]: Factory method 'requestMappingHandlerAdapter' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'messageConverters' defined in class path resource [org/springframework/boot/autoconfigure/http/HttpMessageConvertersAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.http.HttpMessageConverters]: Factory method 'messageConverters' threw exception; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mappingJackson2HttpMessageConverter' defined in class path resource [org/springframework/boot/autoconfigure/http/JacksonHttpMessageConvertersConfiguration$MappingJackson2HttpMessageConverterConfiguration.class]: Unsatisfied dependency expressed through method 'mappingJackson2HttpMessageConverter' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jacksonObjectMapper' defined in class path resource [org/springframework/boot/autoconfigure/jackson/JacksonAutoConfiguration$JacksonObjectMapperConfiguration.class]: Post-processing of merged bean definition failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [com.fasterxml.jackson.databind.ObjectMapper] from ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@2437c6dc] at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:638) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.15.jar:5.3.15] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.15.jar:5.3.15] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.3.jar:2.6.3] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) ~[spring-boot-2.6.3.jar:2.6.3] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:414) ~[spring-boot-2.6.3.jar:2.6.3] at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-2.6.3.jar:2.6.3] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) ~[spring-boot-2.6.3.jar:2.6.3] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) ~[spring-boot-2.6.3.jar:2.6.3] at cn.imcaoxuan.FileManagerApplication.main(FileManagerApplication.java:11) ~[classes/:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.6.3.jar:2.6.3] Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter]: Factory method 'requestMappingHandlerAdapter' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'messageConverters' defined in class path resource [org/springframework/boot/autoconfigure/http/HttpMessageConvertersAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.http.HttpMessageConverters]: Factory method 'messageConverters' threw exception; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mappingJackson2HttpMessageConverter' defined in class path resource [org/springframework/boot/autoconfigure/http/JacksonHttpMessageConvertersConfiguration$MappingJackson2HttpMessageConverterConfiguration.class]: Unsatisfied dependency expressed through method 'mappingJackson2HttpMessageConverter' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jacksonObjectMapper' defined in class path resource [org/springframework/boot/autoconfigure/jackson/JacksonAutoConfiguration$JacksonObjectMapperConfiguration.class]: Post-processing of merged bean definition failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [com.fasterxml.jackson.databind.ObjectMapper] from ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@2437c6dc] at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-5.3.15.jar:5.3.15] ... 24 common frames omitted Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'messageConverters' defined in class path resource [org/springframework/boot/autoconfigure/http/HttpMessageConvertersAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.http.HttpMessageConverters]: Factory method 'messageConverters' threw exception; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mappingJackson2HttpMessageConverter' defined in class path resource [org/springframework/boot/autoconfigure/http/JacksonHttpMessageConvertersConfiguration$MappingJackson2HttpMessageConverterConfiguration.class]: Unsatisfied dependency expressed through method 'mappingJackson2HttpMessageConverter' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jacksonObjectMapper' defined in class path resource [org/springframework/boot/autoconfigure/jackson/JacksonAutoConfiguration$JacksonObjectMapperConfiguration.class]: Post-processing of merged bean definition failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [com.fasterxml.jackson.databind.ObjectMapper] from ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@2437c6dc] at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:638) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1389) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory$DependencyObjectProvider.getIfAvailable(DefaultListableBeanFactory.java:2030) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory$DependencyObjectProvider.ifAvailable(DefaultListableBeanFactory.java:2041) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter.configureMessageConverters(WebMvcAutoConfiguration.java:232) ~[spring-boot-autoconfigure-2.6.3.jar:2.6.3] at org.springframework.web.servlet.config.annotation.WebMvcConfigurerComposite.configureMessageConverters(WebMvcConfigurerComposite.java:137) ~[spring-webmvc-5.3.15.jar:5.3.15] at org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration.configureMessageConverters(DelegatingWebMvcConfiguration.java:118) ~[spring-webmvc-5.3.15.jar:5.3.15] at org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport.getMessageConverters(WebMvcConfigurationSupport.java:865) ~[spring-webmvc-5.3.15.jar:5.3.15] at org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport.requestMappingHandlerAdapter(WebMvcConfigurationSupport.java:673) ~[spring-webmvc-5.3.15.jar:5.3.15] at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$EnableWebMvcConfiguration.requestMappingHandlerAdapter(WebMvcAutoConfiguration.java:419) ~[spring-boot-autoconfigure-2.6.3.jar:2.6.3] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.3.15.jar:5.3.15] ... 25 common frames omitted Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.http.HttpMessageConverters]: Factory method 'messageConverters' threw exception; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mappingJackson2HttpMessageConverter' defined in class path resource [org/springframework/boot/autoconfigure/http/JacksonHttpMessageConvertersConfiguration$MappingJackson2HttpMessageConverterConfiguration.class]: Unsatisfied dependency expressed through method 'mappingJackson2HttpMessageConverter' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jacksonObjectMapper' defined in class path resource [org/springframework/boot/autoconfigure/jackson/JacksonAutoConfiguration$JacksonObjectMapperConfiguration.class]: Post-processing of merged bean definition failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [com.fasterxml.jackson.databind.ObjectMapper] from ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@2437c6dc] at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-5.3.15.jar:5.3.15] ... 49 common frames omitted Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mappingJackson2HttpMessageConverter' defined in class path resource [org/springframework/boot/autoconfigure/http/JacksonHttpMessageConvertersConfiguration$MappingJackson2HttpMessageConverterConfiguration.class]: Unsatisfied dependency expressed through method 'mappingJackson2HttpMessageConverter' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jacksonObjectMapper' defined in class path resource [org/springframework/boot/autoconfigure/jackson/JacksonAutoConfiguration$JacksonObjectMapperConfiguration.class]: Post-processing of merged bean definition failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [com.fasterxml.jackson.databind.ObjectMapper] from ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@2437c6dc] at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:800) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:541) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:1614) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1571) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeans(DefaultListableBeanFactory.java:1415) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1347) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory$DependencyObjectProvider.resolveStream(DefaultListableBeanFactory.java:2117) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory$DependencyObjectProvider.orderedStream(DefaultListableBeanFactory.java:2111) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration.messageConverters(HttpMessageConvertersAutoConfiguration.java:70) ~[spring-boot-autoconfigure-2.6.3.jar:2.6.3] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.3.15.jar:5.3.15] ... 50 common frames omitted Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jacksonObjectMapper' defined in class path resource [org/springframework/boot/autoconfigure/jackson/JacksonAutoConfiguration$JacksonObjectMapperConfiguration.class]: Post-processing of merged bean definition failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [com.fasterxml.jackson.databind.ObjectMapper] from ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@2437c6dc] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:597) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1389) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1309) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:887) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791) ~[spring-beans-5.3.15.jar:5.3.15] ... 72 common frames omitted Caused by: java.lang.IllegalStateException: Failed to introspect Class [com.fasterxml.jackson.databind.ObjectMapper] from ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@2437c6dc] at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:481) ~[spring-core-5.3.15.jar:5.3.15] at org.springframework.util.ReflectionUtils.doWithLocalMethods(ReflectionUtils.java:321) ~[spring-core-5.3.15.jar:5.3.15] at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.buildLifecycleMetadata(InitDestroyAnnotationBeanPostProcessor.java:232) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.findLifecycleMetadata(InitDestroyAnnotationBeanPostProcessor.java:210) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(InitDestroyAnnotationBeanPostProcessor.java:149) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(CommonAnnotationBeanPostProcessor.java:305) ~[spring-context-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyMergedBeanDefinitionPostProcessors(AbstractAutowireCapableBeanFactory.java:1116) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.3.15.jar:5.3.15] ... 82 common frames omitted Caused by: java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/exc/StreamWriteException at java.base/java.lang.Class.getDeclaredMethods0(Native Method) ~[na:na] at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3167) ~[na:na] at java.base/java.lang.Class.getDeclaredMethods(Class.java:2310) ~[na:na] at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:463) ~[spring-core-5.3.15.jar:5.3.15] ... 89 common frames omitted Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.core.exc.StreamWriteException at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582) ~[na:na] at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) ~[na:na] at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) ~[na:na] ... 93 common frames omitted Disconnected from the target VM, address: '127.0.0.1:59002', transport: 'socket' Process finished with exit code 0 报错提示ClassNotFoundException，很明显，这种问题一般都是出现在缺少依赖的情况下的，但是jackson这个东西，我之前一直用的好好的啊！怎么突然就说找不到了呢？ 我在密密麻麻的POM文件中看了半天，也没发现什么问题。我也没做多大改动啊，怎么就跑不起来了呢？ 我想了下，问题会不会是依赖冲突导致的？ 我去看看External Libraries： ...