Java 包org.springframework.stereotype不存在，更多信息

我有一个使用Spring和IntelliJ的web应用程序项目，到目前为止，它工作得很好，但今天我尝试运行它，它开始给我这个错误

这只是一小部分

Error:(27, 29) java: cannot find symbol
  symbol:   class RequestParam
  location: class com.eina.as.controladores.ControladorHome
Error:(8, 47) java: package org.springframework.web.bind.annotation does not exist
Error:(19, 6) java: cannot find symbol
  symbol:   class RequestMapping
  location: class com.eina.as.controladores.ControladorHome
Error:(25, 6) java: cannot find symbol
  symbol:   class RequestMapping
  location: class com.eina.as.controladores.ControladorHome
Error:(42, 26) java: cannot find symbol
  symbol:   class RequestParam
  location: class com.eina.as.controladores.ControladorHome
Error:(28, 29) java: cannot find symbol
  symbol:   class RequestParam
  location: class com.eina.as.controladores.ControladorHome
Error:(6, 38) java: package org.springframework.stereotype does not exist
Error:(9, 47) java: package org.springframework.web.bind.annotation does not exist
Error:(44, 25) java: cannot find symbol
  symbol:   class HttpServletRequest
  location: class com.eina.as.controladores.ControladorHome
Error:(43, 26) java: cannot find symbol
  symbol:   class RequestParam
  location: class com.eina.as.controladores.ControladorHome
Error:(11, 26) java: package javax.servlet.http does not exist
Error:(41, 6) java: cannot find symbol
  symbol:   class RequestMapping
  location: class com.eina.as.controladores.ControladorHome
Error:(29, 29) java: cannot find symbol
  symbol:   class RequestParam
  location: class com.eina.as.controladores.ControladorHome
Error:(16, 2) java: cannot find symbol
  symbol: class Controller
Error:(7, 47) java: package org.springframework.web.bind.annotation does not exist
Error:(26, 29) java: cannot find symbol
  symbol:   class RequestParam
  location: class com.eina.as.controladores.ControladorHome

错误更多，但基本上与上面相同。我不知道发生了什么，我试图重新导入“pom.xml”，但它什么也没做。我已经多次删除和克隆了该项目

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提前感谢

清理maven项目。然后更新项目快照或更新maven项目。还要检查m2目录中的依赖项。然后再次重建项目

清洁Maven项目。项目->右键单击->运行方式->Maven Clean

更新Maven项目。 项目->右键单击->Maven->升级项目 一个新窗口将打开。选择项目并选中“强制更新快照”。然后更新

重建项目。右键单击->运行方式->Maven安装

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命令行上的“mvn干净编译”有效吗？你把这个项目作为maven项目导入了吗？我怎么一步一步地导入呢？