带有测试 Spring Boot 的 Gradle fat jar 的 NoClassDefFoundError

Question

I need to create fat jar in Gradle project with tests where Main method is under src/test. Now I have Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/cli/CommandLineParser when I run fat jar created by 'gradle bootJar'.

My Gradle:

plugins {
    id 'org.springframework.boot' version '2.1.7.RELEASE'
}

apply plugin: 'io.spring.dependency-management'

dependencies {
    compile group: 'org.springframework', name: 'spring-context', version: '5.1.9.RELEASE'
    compile group: 'org.springframework', name: 'spring-web', version: '5.1.9.RELEASE'
    compile group: 'org.springframework', name: 'spring-aop', version: '5.1.9.RELEASE'
    compile group: 'org.springframework', name: 'spring-aspects', version: '5.1.9.RELEASE'
    compile group: 'org.springframework', name: 'spring-test', version: '5.0.5.RELEASE'

    compile group: 'commons-cli', name: 'commons-cli', version: '1.4'
}

bootJar {
    manifest {
        attributes 'Start-Class': 'com.company.MainRunner'
    }
    from sourceSets.test.output.classesDirs
}

My spring.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans default-lazy-init="true" xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                           http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
                           http://www.springframework.org/schema/context
                           http://www.springframework.org/schema/context/spring-context-4.3.xsd
                           http://www.springframework.org/schema/aop
                           http://www.springframework.org/schema/aop/spring-aop-4.3.xsd">

    <aop:aspectj-autoproxy/>

<bean> ... </bean>
<bean> ... </bean>

</beans>

Exception:

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/cli/CommandLineParser

---

Previously following 'gradle shadowJar' code worked well until I added AspectJ to the project

buildscript {
    repositories {
        jcenter()
        mavenCentral()
    }
    dependencies {
        classpath 'com.github.jengelman.gradle.plugins:shadow:4.0.3'
    }
}

apply plugin: 'com.github.johnrengelman.shadow'

shadowJar {
    manifest {
        attributes 'Main-Class': 'com.company.MainRunner'
    }
    from sourceSets.test.output.classesDirs

    configurations = [project.configurations.testRuntime]
}

And error appeared on running 'gradle shadowJar'

Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/aop]

Somewhere I found that shadowJar doesn't work properly with Spring

How can I create fat jar for Spring project with main class under src/test?

Answer 1

This Gradle shadowJar works for me

import com.github.jengelman.gradle.plugins.shadow.transformers.AppendingTransformer

shadowJar {
    mergeServiceFiles()
    transform(AppendingTransformer) { resource = 'META-INF/spring.handlers' }
    transform(AppendingTransformer) { resource = 'META-INF/spring.schemas' }

    manifest {
        attributes 'Main-Class': 'com.company.MainRunner'
    }
    from sourceSets.test.output.classesDirs

    configurations = [project.configurations.testRuntime]
}

Answer 2

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/cli/CommandLineParser

According to the above error, it seems like you have a missing library ( Apache Commons-CLI ) in your classpath. So add that library and try again.

And about this error,

Unable to locate Spring NamespaceHandler for XML schema namespace [ http://www.springframework.org/schema/aop]

The problem occurs when using the aop namespace without having the necessary aop spring library on the classpath.

But I see you have imported that library.

Another cause is you are trying to create a fat.jar file, so spring.handlers / spring.schemas get overwritten when merging multiple spring dependencies into a single jar file.

So I suggest to use Apache Maven Shade Plugin and rebuild the project. And this is the Gradle version of Apache Maven's Shade Plugin .

Answer 3

The Shadow Plugin for gradle has a problem: You have to tell it how to handle file collisions, ie files with the same name. While this is not hard, like @Roman Harasymenko mentioned and I use it (Kotlin DSL):

tasks.withType<ShadowJar> {
    mergeServiceFiles()
    append("META-INF/spring.handlers")
    append("META-INF/spring.schemas")
    append("META-INF/spring.tooling")
    transform(
        PropertiesFileTransformer().apply {
            paths = mutableListOf("META-INF/spring.factories")
            mergeStrategy = "append"
        })
}

it doesn't tell in its current version when such a conflict occurs, so you have to waste big amounts of time finding the conflicts yourself. But there is a pull request that it tells if there is a collision: https://github.com/johnrengelman/shadow/pull/773 . Until the pull request gets merged you could use the forked branch to be always informed about file collisions: https://github.com/JD-CSTx/shadow/tree/chapmajs-collision_logging