我在我的 spring + hibernate 项目中使用 Spring 4.0.0 RELEASE jar，hibernate-coe 4.3.0 jar。
我遇到了一个错误，即找不到 org.hibernate.engine.FilterDefinition。实际上，在旧的 hibernate 核心 jar 中，我们有这个类，但在 4.3.0 版本中没有。事实上，我们在 4.3.0 版本中有 org.hibernate.engine.spi.FilterDefinition。
但我不确定这个类在运行时是如何依赖的。同时，我在我的应用程序中使用 glassfish 服务器。
请告诉我 spring 4.0.0 和 hibernate 4.3.0 版本的兼容性，并向我推荐这两个版本的最新兼容版本。
我的代码是: dispatcher-servlet 有
<bean id="hibernateTransactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="annotatedClasses">
<list>
<value>com.venkat.homeapp.entity.CustomerEntity</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
</props>
</property>
</bean>
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${database.driver}" />
<property name="url" value="${database.url}" />
<property name="username" value="${database.user}" />
<property name="password" value="${database.password}" />
</bean>
我的 Controller 类是:
@Controller
@RequestMapping("/")
@ComponentScan("com.venkat.homeapp.service")
public class HomeAppController {
@Autowired
private CustomerService customerService;
:
:
}
我能看到的日志是:
INFO: WebModule[null] ServletContext.log():No Spring WebApplicationInitializer types detected on classpath
INFO: WebModule[null] ServletContext.log():Initializing Spring FrameworkServlet 'HomeApp'
INFO: FrameworkServlet 'HomeApp': initialization started
INFO: Refreshing WebApplicationContext for namespace 'HomeApp-servlet': startup date [Mon Jan 20 23:42:45 IST 2014]; root of context hierarchy
INFO: Loading XML bean definitions from ServletContext resource [/WEB-INF/HomeApp-servlet.xml]
INFO: Loading properties file from class path resource [jdbc.properties]
INFO: JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
SEVERE: Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'homeAppController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.venkat.homeapp.service.CustomerService com.venkat.homeapp.controller.HomeAppController.customerService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.venkat.homeapp.dao.CustomerDAO com.venkat.homeapp.service.impl.CustomerServiceImpl.customerDAO; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.venkat.homeapp.dao.impl.CustomerDAOImpl.sessionFactory; nested exception is java.lang.NoClassDefFoundError: [Lorg/hibernate/engine/FilterDefinition;
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:700)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:643)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:606)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:657)
at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:525)
at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:466)
at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
at javax.servlet.GenericServlet.init(GenericServlet.java:244)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1583)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1382)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5670)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:5912)
at com.sun.enterprise.web.WebModule.start(WebModule.java:691)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:1041)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:1024)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:747)
at com.sun.enterprise.web.WebContainer.loadWebModule(WebContainer.java:2278)
at com.sun.enterprise.web.WebContainer.loadWebModule(WebContainer.java:1924)
at com.sun.enterprise.web.WebApplication.start(WebApplication.java:139)
at org.glassfish.internal.data.EngineRef.start(EngineRef.java:122)
at org.glassfish.internal.data.ModuleInfo.start(ModuleInfo.java:291)
at org.glassfish.internal.data.ApplicationInfo.start(ApplicationInfo.java:352)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:497)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:219)
at org.glassfish.deployment.admin.DeployCommand.execute(DeployCommand.java:491)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:527)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:523)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:356)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2.execute(CommandRunnerImpl.java:522)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:546)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:1423)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.access$1500(CommandRunnerImpl.java:108)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1762)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1674)
at com.sun.enterprise.v3.admin.AdminAdapter.doCommand(AdminAdapter.java:534)
at com.sun.enterprise.v3.admin.AdminAdapter.onMissingResource(AdminAdapter.java:224)
at org.glassfish.grizzly.http.server.StaticHttpHandler.service(StaticHttpHandler.java:297)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:246)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
at java.lang.Thread.run(Thread.java:744)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.venkat.homeapp.service.CustomerService com.venkat.homeapp.controller.HomeAppController.customerService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.venkat.homeapp.dao.CustomerDAO com.venkat.homeapp.service.impl.CustomerServiceImpl.customerDAO; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.venkat.homeapp.dao.impl.CustomerDAOImpl.sessionFactory; nested exception is java.lang.NoClassDefFoundError: [Lorg/hibernate/engine/FilterDefinition;
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
... 65 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.venkat.homeapp.dao.CustomerDAO com.venkat.homeapp.service.impl.CustomerServiceImpl.customerDAO; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.venkat.homeapp.dao.impl.CustomerDAOImpl.sessionFactory; nested exception is java.lang.NoClassDefFoundError: [Lorg/hibernate/engine/FilterDefinition;
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1014)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:957)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:855)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:480)
... 67 more
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.venkat.homeapp.dao.CustomerDAO com.venkat.homeapp.service.impl.CustomerServiceImpl.customerDAO; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.venkat.homeapp.dao.impl.CustomerDAOImpl.sessionFactory; nested exception is java.lang.NoClassDefFoundError: [Lorg/hibernate/engine/FilterDefinition;
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
... 78 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.venkat.homeapp.dao.impl.CustomerDAOImpl.sessionFactory; nested exception is java.lang.NoClassDefFoundError: [Lorg/hibernate/engine/FilterDefinition;
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1014)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:957)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:855)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:480)
... 80 more
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.venkat.homeapp.dao.impl.CustomerDAOImpl.sessionFactory; nested exception is java.lang.NoClassDefFoundError: [Lorg/hibernate/engine/FilterDefinition;
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
... 91 more
Caused by: java.lang.NoClassDefFoundError: [Lorg/hibernate/engine/FilterDefinition;
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Class.java:2397)
at java.lang.Class.getDeclaredFields(Class.java:1806)
at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.findPersistenceMetadata(PersistenceAnnotationBeanPostProcessor.java:392)
at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(PersistenceAnnotationBeanPostProcessor.java:332)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyMergedBeanDefinitionPostProcessors(AbstractAutowireCapableBeanFactory.java:908)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:512)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1014)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:957)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:855)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:480)
... 93 more
Caused by: java.lang.ClassNotFoundException: org.hibernate.engine.FilterDefinition
at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1761)
at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1611)
... 109 more
最佳答案
如果你使用的是 hibernate4.x
解决java.lang.NoClassDefFoundError引起的异常:[Lorg/hibernate/engine/FilterDefinition;
在 dipatcher-servlet 中，而不是
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
使用
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
关于java - spring 4.0.0 与 hibernate 4.30 的兼容性，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21241210/
我真的很习惯使用Ruby编写以下代码:my_hash={}my_hash['test']=1Java中对应的数据结构是什么？ 最佳答案 HashMapmap=newHashMap();map.put("test",1);我假设？ 关于java-等价于Java中的RubyHash，我们在StackOverflow上找到一个类似的问题： https://stackoverflow.com/questions/22737685/
我正在使用Ruby2.1.1和Rails4.1.0.rc1。当执行railsc时，它被锁定了。使用Ctrl-C停止，我得到以下错误日志:~/.rvm/gems/ruby-2.1.1/gems/spring-1.1.2/lib/spring/client/run.rb:47:in`gets':Interruptfrom~/.rvm/gems/ruby-2.1.1/gems/spring-1.1.2/lib/spring/client/run.rb:47:in`verify_server_version'from~/.rvm/gems/ruby-2.1.1/gems/spring-1.1.
我正在尝试使用boilerpipe来自JRuby。我看过guide从JRuby调用Java，并成功地将它与另一个Java包一起使用，但无法弄清楚为什么同样的东西不能用于boilerpipe。我正在尝试基本上从JRuby中执行与此Java等效的操作:URLurl=newURL("http://www.example.com/some-location/index.html");Stringtext=ArticleExtractor.INSTANCE.getText(url);在JRuby中试过这个:require'java'url=java.net.URL.new("http://www
我只想对我一直在思考的这个问题有其他意见，例如我有classuser_controller和classuserclassUserattr_accessor:name,:usernameendclassUserController//dosomethingaboutanythingaboutusersend问题是我的User类中是否应该有逻辑user=User.newuser.do_something(user1)oritshouldbeuser_controller=UserController.newuser_controller.do_something(user1,user2)我
什么是ruby的rack或python的Java的wsgi？还有一个路由库。 最佳答案 来自Python标准PEP333:Bycontrast,althoughJavahasjustasmanywebapplicationframeworksavailable,Java's"servlet"APImakesitpossibleforapplicationswrittenwithanyJavawebapplicationframeworktoruninanywebserverthatsupportstheservletAPI.ht
这篇文章是继上一篇文章“Observability：从零开始创建Java微服务并监控它（一）”的续篇。在上一篇文章中，我们讲述了如何创建一个Javaweb应用，并使用Filebeat来收集应用所生成的日志。在今天的文章中，我来详述如何收集应用的指标，使用APM来监控应用并监督web服务的在线情况。源码可以在地址 https://github.com/liu-xiao-guo/java_observability 进行下载。摄入指标指标被视为可以随时更改的时间点值。当前请求的数量可以改变任何毫秒。你可能有1000个请求的峰值，然后一切都回到一个请求。这也意味着这些指标可能不准确，你还想提取最小/
HashMap中为什么引入红黑树，而不是AVL树呢1.概述开始学习这个知识点之前我们需要知道，在JDK1.8以及之前，针对HashMap有什么不同。JDK1.7的时候，HashMap的底层实现是数组+链表JDK1.8的时候，HashMap的底层实现是数组+链表+红黑树我们要思考一个问题，为什么要从链表转为红黑树呢。首先先让我们了解下链表有什么不好？？？2.链表上述的截图其实就是链表的结构，我们来看下链表的增删改查的时间复杂度增：因为链表不是线性结构，所以每次添加的时候，只需要移动一个节点，所以可以理解为复杂度是N(1)删：算法时间复杂度跟增保持一致查：既然是非线性结构，所以查询某一个节点的时候
遍历文件夹我们通常是使用递归进行操作，这种方式比较简单，也比较容易理解。本文为大家介绍另一种不使用递归的方式，由于没有使用递归，只用到了循环和集合，所以效率更高一些！一、使用递归遍历文件夹整体思路1、使用File封装初始目录，2、打印这个目录3、获取这个目录下所有的子文件和子目录的数组。4、遍历这个数组，取出每个File对象4-1、如果File是否是一个文件，打印4-2、否则就是一个目录，递归调用代码实现publicclassSearchFile{publicstaticvoidmain(String[]args){//初始目录Filedir=newFile("d:/Dev");Datebeg
1.在Python3中，下列关于数学运算结果正确的是:（B）a=10b=3print(a//b)print(a%b)print(a/b)A.3，3，3.3333...B.3，1，3.3333...C.3.3333...，3.3333...，3D.3.3333...，1，3.3333...解析： 在Python中，//表示地板除（向下取整），%表示取余，/表示除（Python2向下取整返回3）2.如下程序Python2会打印多少个数:（D）k=1000whilek>1: print(k)k=k/2A.1000 B.10C.11D.9解析： 按照题意每次循环K/2，直到K值小于等
转自:spring.profiles.active和spring.profiles.include的使用及区别说明下文笔者讲述spring.profiles.active和spring.profiles.include的区别简介说明,如下所示我们都知道，在日常开发中,开发|测试|生产环境都拥有不同的配置信息如：jdbc地址、ip、端口等此时为了避免每次都修改全部信息，我们则可以采用以上的属性处理此类异常spring.profiles.active属性例：配置文件,可使用以下方式定义application-${profile}.properties开发环境配置文件:application-dev