那些年Intellij Idea踩过的坑

     在 Intellij Idea  中使用maven时，所有 scope 为 provided 的依赖都是不会被加入到 classpath 中的，目前该bug尚未被修复。

     如果你做Spring Boot开发，有带provided的依赖时，直接在IDE中运行项目会导致ClassNotFound异常。

 https://youtrack.jetbrains.com/issue/IDEA-107048

 

解决方案一：

解决方案简单粗暴，找到pom.xml中的如下依赖

1.  
   <dependency>
2.  
   <groupId>org.springframework.boot</groupId>
3.  
   <artifactId>spring-boot-starter-tomcat</artifactId>
4.  
   <!--<scope>provided</scope>-->
5.  
   </dependency>

将对应的scope 注释掉即可

 

解决方案二：

【推荐】在运行配置Configuration选项卡下Use classpath of module的下方有个复选框 Include dependences with "Provided" scope 把这个勾上就可以了。

解决方案三：

当packaging为jar时，直接更改scope为compile（不推荐）

 

 

 

compile:

This is the default scope, used if none is specified. Compile dependencies are available in all classpaths of a project. Furthermore, those dependencies are propagated to dependent projects.

（未指定scope时默认使用该项。项目始终依赖使用该jar包。会传递依赖的项目）

 

provided:

This is much like compile, but indicates you expect the JDK or a container to provide the dependency at runtime. For example, when building a web application for the Java Enterprise Edition, you would set the dependency on the Servlet API and related Java EE APIs to scope provided because the web container provides those classes. This scope is only available on the compilation and test classpath, and is not transitive.

（与compile类似，但表明你期望JDK或容器在运行时提供的依赖。例如，当构建一个Web应用程序的java企业版，你将依赖Servlet API和相关的java EE API提供的Web容器提供的范围，用于编译和测试阶段，不具有传递性。jar包不会包含依赖项）

 

runtime:

This scope indicates that the dependency is not required for compilation, but is for execution. It is in the runtime and test classpaths, but not the compile classpath.

（表示被依赖项目不会参与项目的编译，但用于运行和测试。与compile相比，跳过了编译这个环节）

 

test:

This scope indicates that the dependency is not required for normal use of the application, and is only available for the test compilation and execution phases. This scope is not transitive.

（此范围表示应用程序的正常使用不需要依赖项，只适用于测试编译和执行阶段。不具有传递性。）

 

system:

This scope is similar to provided except that you have to provide the JAR which contains it explicitly. The artifact is always available and is not looked up in a repository.

（与provided相似，但必须我们给它提供显式JAR包。不会从maven远程中央仓库下载，而是从本地Maven仓库中获取。）

 

import (only available in Maven 2.0.9 or later)：

This scope is only supported on a dependency of type pom in the section. It indicates the dependency to be replaced with the effective list of dependencies in the specified POM’s section. Since they are replaced, dependencies with a scope of import do not actually participate in limiting the transitivity of a dependency.

（import scope只能用在dependencyManagement里面。表示从其它的pom中导入dependency的配置。）