有效沟通问答-【官方】百战程序员_IT在线教育培训机构

        MongoClient client = new MongoClient("192.168.0.105",27017);
        MongoDatabase database = client.getDatabase("develop");
//        MongoCollection dev = database.getCollection("dev");
        database.createCollection("devtest");
        System.out.println("OK-----");

JAVA 全系列/第十三阶段：分布式文件存储与数据缓存/MongoDB 32327楼

#测试方法的重写

class Person:

    def __init__(self,name,age):
        self.name = name
        self.__age = age

    def say_age(self):
        print("我的年龄是{0}".format(self.__age))

    def say_introduce(self):
        print("我的名字是{0}".format(self.name))

class Student(Person):

    def __init__(self,name,age,score):#私有方法和私有属性，子类可以继承，但是不能直接使用
        Person.__init__(self,name,age)  #调用父类的构造器,必须是显式的调用父类初始化方法，不然解释器不会去调用
        self.score = score

    def say_introduce(self):   #子类重写了父类的方法
        print("报告老师，我的名字是{0}".format(self.name))

s1 = Student("yuyu",18,90)
s1.say_age()
s1.say_introduce()

运行结果：

问题：老师，在父类的构造方法中已经把age属性私有化了，为什么在子类调用的时候不用特定的形式就可以调用出来？

Python 全系列/第一阶段：Python入门/面向对象 32328楼

老师，我这边，本段视频声音播放时，时大时小。

Python 全系列/第二阶段：Python 深入与提高/模块 32329楼

主键作为唯一标识，为何会有同时设置两个primary key

Python 全系列/第五阶段：数据库编程/mysql的使用 32330楼

老师，想问下name = event.widget.winfo_name() 这句话是什么意思

包括之前的，widget.winfo_x(),这种，网上也没查到，也不能查看源码，能详细说明下这种这种含义吗？

Python 全系列/第二阶段：Python 深入与提高/GUI编程（隐藏） 32331楼

这几个公式中的k和n分别代表什么？按照视频中的讲解，如果是分别对每一列求平均值和方差，k和n应该是相等的，为什么会是两个字母代表？

人工智能/第五阶段：机器学习-线性回归/归一化 32332楼

老师，反射invoke（）方法是做什么的。。。。执行方法？

JAVA 全系列/第二阶段：JAVA 基础深化和提高/反射技术（旧） 32333楼

视频是不是少了最前面一点？为啥显示没找到数据库？

JAVA 全系列/第三阶段：数据库编程/MySQL数据库的使用 32334楼

老师好，为什么我的static变量序列化成功了。

JAVA 全系列/第二阶段：JAVA 基础深化和提高/IO 流技术（旧） 32335楼

老师，出现了如下报错是什么原因呢？我的HTML中已经添加了

<link rel="shortcut icon" href="../resources/favicon.ico" th:href="@{/static/favicon.ico}"/>

麻烦老师看看

org.thymeleaf.exceptions.TemplateInputException: Error resolving template [favicon.ico], template might not exist or might not be accessible by any of the configured Template Resolvers

at org.thymeleaf.engine.TemplateManager.resolveTemplate(TemplateManager.java:869) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:607) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098) [thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1072) [thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.thymeleaf.spring5.view.ThymeleafView.renderFragment(ThymeleafView.java:362) [thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.thymeleaf.spring5.view.ThymeleafView.render(ThymeleafView.java:189) [thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1373) [spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1118) [spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1057) [spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) [spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) [spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) [spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) [spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) [tomcat-embed-websocket-9.0.35.jar:9.0.35]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) [spring-web-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) [spring-web-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) [spring-web-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590) [tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.35.jar:9.0.35]

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_101]

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_101]

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.35.jar:9.0.35]

at java.lang.Thread.run(Thread.java:745) [na:1.8.0_101]

2020-05-29 17:55:41.827 ERROR 42664 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.thymeleaf.exceptions.TemplateInputException: Error resolving template [favicon.ico], template might not exist or might not be accessible by any of the configured Template Resolvers] with root cause

org.thymeleaf.exceptions.TemplateInputException: Error resolving template [favicon.ico], template might not exist or might not be accessible by any of the configured Template Resolvers

at org.thymeleaf.engine.TemplateManager.resolveTemplate(TemplateManager.java:869) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:607) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1072) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.thymeleaf.spring5.view.ThymeleafView.renderFragment(ThymeleafView.java:362) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.thymeleaf.spring5.view.ThymeleafView.render(ThymeleafView.java:189) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]

at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1373) ~[spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1118) ~[spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1057) ~[spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.35.jar:9.0.35]

at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.6.RELEASE.jar:5.2.6.RELEASE]

at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.35.jar:9.0.35]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.35.jar:9.0.35]