当我从 Spring Boot Jar 运行但不是通过 Eclipse 时出现 ClassNotFoundException

Question

I have a multiple level Maven project with Spring Boot.

ParentProject
|_ Project1
   |_pom.xml
|_ LibraryProject
   |_pom.xml
|_ Project2
   |_pom.xml

For ParentProject the parent is defined thus:

<parent>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-parent</artifactId>
   <version>1.5.9.RELEASE</version>
   <relativePath></relativePath>
</parent>

For Project1, LibraryProject and Project2:

<parent>
   <groupId>ParentProject</groupId>
   <artifactId>ParentProject</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <relativePath>..</relativePath>
</parent>

Project1 and Project2 depend on classes from LibraryProject. When I execute from Eclipse, Project1 and Project2 both find all of their classes and all of the classes in LibraryProject. When I create a Project1.jar with

mvn clean install package

And then run it, I get ClassNotFoundExceptions on the classes that are in LibraryProject. LibraryProject is a dependency of Project1 and is built before Project1.

ParentProject uses spring-boot-parent as its parent. It builds in the order:

1) LibraryProject
2) Project1
3) Project2

I've brought in the maven-compiler-plugin, maven-jar-plugin, maven-remote-resources-plugin.

I'm just out of ideas. It compiles in eclipse and maven can build it. But running it creates exceptions.

Thank you all in advance.

Answer 1

It's cause by ClassLoader, SpringBoot run with java -jar has it's own ClassLoader.It will load Class from BOOT-INF/classes and BOOT-INF/lib,but Eclipse will add all dependency to classpath. So Eclipse can find the Class. you can checkout you pom.xml.