java - Maven项目在eclipse中抛出ClassNotFoundException

Question

当在 Eclipse 中运行带有 Maven 依赖项的 Spring Boot 应用程序时，我在启动时出现以下异常:

java.lang.NoClassDefFoundError: org/springframework/web/context/support/GenericWebApplicationContext
at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_92]
at java.lang.ClassLoader.defineClass(Unknown Source) ~[na:1.8.0_92]
at java.security.SecureClassLoader.defineClass(Unknown Source) ~[na:1.8.0_92]
at java.net.URLClassLoader.defineClass(Unknown Source) ~[na:1.8.0_92]
at java.net.URLClassLoader.access$100(Unknown Source) ~[na:1.8.0_92]
at java.net.URLClassLoader$1.run(Unknown Source) ~[na:1.8.0_92]
at java.net.URLClassLoader$1.run(Unknown Source) ~[na:1.8.0_92]
at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_92]
at java.net.URLClassLoader.findClass(Unknown Source) ~[na:1.8.0_92]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_92]
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) ~[na:1.8.0_92]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_92]
at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_92]
at java.lang.ClassLoader.defineClass(Unknown Source) ~[na:1.8.0_92]
at java.security.SecureClassLoader.defineClass(Unknown Source) ~[na:1.8.0_92]
at java.net.URLClassLoader.defineClass(Unknown Source) ~[na:1.8.0_92]
at java.net.URLClassLoader.access$100(Unknown Source) ~[na:1.8.0_92]
at java.net.URLClassLoader$1.run(Unknown Source) ~[na:1.8.0_92]
at java.net.URLClassLoader$1.run(Unknown Source) ~[na:1.8.0_92]
at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_92]
at java.net.URLClassLoader.findClass(Unknown Source) ~[na:1.8.0_92]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_92]
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) ~[na:1.8.0_92]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_92]
at java.lang.Class.forName0(Native Method) ~[na:1.8.0_92]
at java.lang.Class.forName(Unknown Source) ~[na:1.8.0_92]
at org.springframework.boot.SpringApplication.createApplicationContext(SpringApplication.java:574) ~[spring-boot-1.3.0.RELEASE.jar:1.3.0.RELEASE]
at org.springframework.boot.SpringApplication.doRun(SpringApplication.java:325) ~[spring-boot-1.3.0.RELEASE.jar:1.3.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:295) ~[spring-boot-1.3.0.RELEASE.jar:1.3.0.RELEASE]
at co.hafiz.cm.launcher.Launcher.lambda$0(Launcher.java:33) [classes/:na]
at java.util.concurrent.FutureTask.run(Unknown Source) ~[na:1.8.0_92]
at java.lang.Thread.run(Unknown Source) ~[na:1.8.0_92]
Caused by: java.lang.ClassNotFoundException: org.springframework.web.context.support.GenericWebApplicationContext
at java.net.URLClassLoader.findClass(Unknown Source) ~[na:1.8.0_92]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_92]
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) ~[na:1.8.0_92]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_92]
... 32 common frames omitted

在 Eclipse 的 Maven 依赖项中我得到:

如您所见spring-web可用其中包含 org.springframework.web.context.support.GenericWebApplicationContext 会出现什么问题？

Answer 1

在我的 Spring Boot 项目中添加依赖项 spring-boot-starter-web 解决了同样的错误。另外，您似乎对 Spring Boot 有很多不必要的依赖项。在 Spring 框架中可能需要一些，但在 Spring Boot 中则不需要。