Gradle无法生成Fat Jar但Maven可正常构建问题求助

问题背景 #

尝试通过Gradle构建Fat Jar时，无论是使用Kotlin脚本还是Groovy脚本（参考过两种主流方案），均出现「无法解压指定POM文件」的错误，但使用Maven插件可正常生成Fat Jar。

相关脚本 #

Gradle Groovy脚本 #

plugins {
    id 'java'
}

repositories {
    mavenCentral()
}

dependencies {
    testImplementation(platform("org.junit:junit-bom:5.10.0"))
    testImplementation("org.junit.jupiter:junit-jupiter")
    implementation("org.neo4j.driver:neo4j-java-driver:5.27.0")
    implementation("org.mongodb:mongodb-driver-sync:4.8.2")
    implementation("org.mongodb:mongodb-driver:3.12.7")
    implementation( "co.elastic.clients:elasticsearch-java:8.12.0")
    implementation( "org.elasticsearch.client:elasticsearch-rest-high-level-client:7.17.16")
    implementation( "org.elasticsearch.client:transport:7.17.17")
    implementation( "com.datastax.oss:java-driver-core:4.15.0")
    implementation( "commons-logging:commons-logging:1.1.3")
    implementation( "org.apache.hive:hive-jdbc:3.1.2")
    implementation( "com.fasterxml.jackson.core:jackson-annotations:2.18.1")
    implementation( "com.fasterxml.jackson.core:jackson-core:2.18.1")
}

jar {
    manifest {
        attributes "Main-Class": "com.baeldung.fatjar.Application"
    }

    from {
        configurations.runtimeClasspath.collect { it.isDirectory() ? it : zipTree(it) }
    }
}

task customFatJar(type: Jar) {
    manifest {
        attributes 'Main-Class': 'com.baeldung.fatjar.Application'
    }
    archiveBaseName = 'all-in-one-jar'
    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
    from { configurations.runtimeClasspath.collect { it.isDirectory() ? it : zipTree(it) } }
    with jar
}

Gradle Kotlin脚本 #

plugins {
    id("java")
}

group = "org.example"
version = "1.0-SNAPSHOT"

repositories {
    mavenCentral()
}

dependencies {
    testImplementation(platform("org.junit:junit-bom:5.10.0"))
    testImplementation("org.junit.jupiter:junit-jupiter")
    implementation("org.neo4j.driver:neo4j-java-driver:5.27.0")
    implementation("org.mongodb:mongodb-driver-sync:4.8.2")
    implementation("org.mongodb:mongodb-driver:3.12.7")
    implementation( "co.elastic.clients:elasticsearch-java:8.12.0")
    implementation( "org.elasticsearch.client:elasticsearch-rest-high-level-client:7.17.16")
    implementation( "org.elasticsearch.client:transport:7.17.17")
    implementation( "com.datastax.oss:java-driver-core:4.15.0")
    implementation( "commons-logging:commons-logging:1.1.3")
    implementation( "org.apache.hive:hive-jdbc:3.1.2")
    implementation( "com.fasterxml.jackson.core:jackson-annotations:2.18.1")
    implementation( "com.fasterxml.jackson.core:jackson-core:2.18.1")
}

tasks.jar {
    manifest.attributes["Main-Class"] = "com.example.MyMainClass"
    val dependencies = configurations
        .runtimeClasspath
        .get()
        .map { zipTree(it)}
            from(dependencies)
    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
}

tasks.test {
    useJUnitPlatform()
}

错误信息 #

Execution failed for task ':customFatJar'.

Cannot expand ZIP '/Users/user1/.gradle/caches/modules-2/files-2.1/org.apache.curator/apache-curator/2.12.0/b1ff6ce0741facb15217ae9254ee7167bc7b15e/apache-curator-2.12.0.pom'.

• Try:

Run with --stacktrace option to get the stack trace.
Run with --info or --debug option to get more log output.
Run with --scan to get full insights.
Get more help at https://help.gradle.org. BUILD FAILED in 31s 2 actionable tasks: 1 executed, 1 up-to-date

可行的Maven方案 #

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>3.3.0</version>
            <configuration>
                <archive>
                    <manifest> <mainClass>org.example</mainClass></manifest>
                </archive>
            </configuration>
        </plugin>
    </plugins>
</build>

解决方法 #

1. 清理Gradle缓存 #

执行以下命令，强制刷新依赖并清理可能损坏的缓存文件：

./gradlew clean build --refresh-dependencies

2. 修改脚本过滤非Jar文件 #

错误核心是runtimeClasspath中混入了POM文件，导致Gradle尝试解压非Zip格式的文件。修改脚本仅处理Jar文件：

Groovy脚本修改

将customFatJar和jar任务中的from块替换为：

from {
    configurations.runtimeClasspath.collect { 
        it.isDirectory() ? it : (it.name.endsWith('.jar') ? zipTree(it) : null) 
    }.findAll()
}

Kotlin脚本修改

将tasks.jar中的依赖处理部分替换为：

val dependencies = configurations
    .runtimeClasspath
    .get()
    .map { if (it.name.endsWith(".jar")) zipTree(it) else null }
    .filterNotNull()
from(dependencies)

3. 使用Shadow插件（推荐） #

Gradle官方更推荐使用Shadow插件构建Fat Jar，它会自动处理依赖过滤、重复类等问题：

Groovy脚本配置

plugins {
    id 'java'
    id 'com.github.johnrengelman.shadow' version '8.1.1'
}

shadowJar {
    manifest {
        attributes 'Main-Class': 'com.baeldung.fatjar.Application'
    }
    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
}

Kotlin脚本配置

plugins {
    java
    id("com.github.johnrengelman.shadow") version "8.1.1"
}

tasks.shadowJar {
    manifest.attributes["Main-Class"] = "com.example.MyMainClass"
    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
}

执行构建命令：

./gradlew shadowJar

生成的Fat Jar位于build/libs/[项目名]-[版本]-all.jar。

内容的提问来源于stack exchange，提问作者echo