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老师，您好！pycharm中如何使用matplotlib这个模块？

Python 全系列/第十八阶段：数据分析-数据可视化/matplotlib 22351楼

老师这哪个是我虚拟机大的ip地址啊？我要是用xshell连接用哪个地址？

JAVA 全系列/第十一阶段：分布式RPC调用和分布式文件存储/Zookeeper 22352楼

老师，输入和库中相同的用户名和手机号之后，不会弹出“已存在”，并且会报错请求失败，这个要去哪里修改呢

JAVA 全系列/（旧的隐藏）第二十一阶段：百战商城项目(Spring Cloud最新架构)/百战商城项目 22353楼

服务器运行报错，jar包也是按照视频内容添加的，麻烦老师帮忙检查一下

ajaxDemo.zip

JAVA 全系列/第五阶段：JavaWeb开发/Ajax技术详解（旧） 22354楼

老师，点击加入购物车后没有跳转，浏览器报这个错，但是idea和vscode里都没报错，怎么办呢

JAVA 全系列/（旧的隐藏）第二十一阶段：百战商城项目(Spring Cloud最新架构)/百战商城项目 22355楼

老师，您好！安装不了xlutils，报错就是这么多

Python 全系列/ 第十四阶段：自动化操作办公软件、邮件、定时任务等/自动化操作办公软件、邮件、定时任务等 22356楼

打开项目为什么这么多报错

JAVA 全系列/第十八阶段：亿级高并发电商项目_架构/编码（旧）/电商：完成CMS系统 22357楼

#coding=UTF-8

from threading import Thread, Event
from time import sleep
from random import randint


def door():
    global state
    while True:
        if even.is_set():#如果even事件为真，则执行
            print('我是门：门开着，可以通行~')
            sleep(1)
        else:
            print('我是门：门关了~请刷卡！')
            state = 0#门已关闭，开门循环重置为0
            even.wait()#even事件为等待，进程暂停
        if state > 3:#state在3次循环后
            print('我是门：超过3 秒，门自动关门')
            even.clear() #even事件为假，所有even.wait()发挥作用，将进程暂停
        state +=1#循环一次，state+1，控制门开启时间
        sleep(1)#线程暂停1秒，控制循环时间
def person():
    global state
    n = 0#人员编号
    while True:
        if even.is_set():
            print('我是人：门开着：{}号进入'.format(n))
        else:
            even.set()#将even事件标记为真
            state = 0#开门循环重置为0
            print('我是人：门关着，{}号人刷卡进门'.format(n))
        n += 1
        sleep(randint(1, 10))#随机1-10米秒来一个人，模拟刷卡
if __name__ == '__main__':
    state = 0
    even = Event()
    even.set()
    d = Thread(target=door)
    d.start()
    p = Thread(target=person)
    p.start()

老师，在执行的时候应该先提示

我是门：门关了~请刷卡！

但是我的这个程序，直接就是开着门的，请帮忙看看问题在哪里，谢谢

Python 全系列/第三阶段：Python 网络与并发编程/并发编程 22358楼

加上@Value("${msg}")之后启动报错

logback.rar

2021-04-19 13:28:18.145 [main] INFO com.bjsxt.logback.LogbackApplication - Starting LogbackApplication using Java 1.8.0_131 on LY with PID 17640 (D:\demo\springBoot\logback\target\classes started by yu lin in D:\demo\springBoot\logback)

2021-04-19 13:28:18.150 [main] INFO com.bjsxt.logback.LogbackApplication - No active profile set, falling back to default profiles: default

2021-04-19 13:28:19.303 [main] INFO o.s.boot.web.embedded.tomcat.TomcatWebServer - Tomcat initialized with port(s): 8080 (http)

2021-04-19 13:28:19.312 [main] INFO org.apache.coyote.http11.Http11NioProtocol - Initializing ProtocolHandler ["http-nio-8080"]

2021-04-19 13:28:19.313 [main] INFO org.apache.catalina.core.StandardService - Starting service [Tomcat]

2021-04-19 13:28:19.313 [main] INFO org.apache.catalina.core.StandardEngine - Starting Servlet engine: [Apache Tomcat/9.0.45]

2021-04-19 13:28:19.469 [main] INFO o.a.c.core.ContainerBase.[Tomcat].[localhost].[/] - Initializing Spring embedded WebApplicationContext

2021-04-19 13:28:19.469 [main] INFO o.s.b.w.s.c.ServletWebServerApplicationContext - Root WebApplicationContext: initialization completed in 1249 ms

2021-04-19 13:28:19.523 [main] WARN o.s.b.w.s.c.AnnotationConfigServletWebServerApplicationContext - Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloController': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'msg' in value "${msg}"

2021-04-19 13:28:19.526 [main] INFO org.apache.catalina.core.StandardService - Stopping service [Tomcat]

2021-04-19 13:28:19.540 [main] INFO o.s.b.a.l.ConditionEvaluationReportLoggingListener -

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.

2021-04-19 13:28:19.565 [main] ERROR org.springframework.boot.SpringApplication - Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloController': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'msg' in value "${msg}"

at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:405)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1413)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524)

at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)

at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)

at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944)

at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)

at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)

at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144)

at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:782)

at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:774)

at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:439)

at org.springframework.boot.SpringApplication.run(SpringApplication.java:339)

at org.springframework.boot.SpringApplication.run(SpringApplication.java:1340)

at org.springframework.boot.SpringApplication.run(SpringApplication.java:1329)

at com.bjsxt.logback.LogbackApplication.main(LogbackApplication.java:10)

Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'msg' in value "${msg}"

at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:178)

at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124)

at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:239)

at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:210)

at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties$0(PropertySourcesPlaceholderConfigurer.java:175)

at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:936)

at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1321)

at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300)

at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:657)

at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640)

at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119)

at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399)

... 18 common frames omitted

Process finished with exit code 1

JAVA 全系列/第九阶段：Spring Boot实战/Spring Boot 22359楼

install的时候报错Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:3.2.0:resources

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:3.2.0:resources (default-resources) on project logback: Input length = 1 -> [Help 1]

[ERROR]

[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.

[ERROR] Re-run Maven using the -X switch to enable full debug logging.

[ERROR]

[ERROR] For more information about the errors and possible solutions, please read the following articles:

[ERROR] [Help 1]

解决办法：将本地仓库repository\org\apache\maven下的plugins删了重新clean、install

JAVA 全系列/第九阶段：Spring Boot实战/Spring Boot 22360楼

什么是字符串呢？。。。。。。。。。。。。。。。。

JAVA 全系列/第一阶段：JAVA 快速入门/变量、数据类型、运算符 22361楼

老师，请问，这里看箱图，老师说这两组数据方差还是比较齐的，但是通过方法算出来的p值小于0.05，拒绝原假设，又说明方差不齐，这怎么是矛盾的呢

Python 全系列/第二十阶段：数据分析-统计分析/Python统计分析 22362楼