Unable to run repacked spring boot jar caused by "Unable to open nested entry"

Question

I am setting up a build pipeline for a spring boot project.

It has three stages so far:

build: compile-->unit test-->archive the jar
deploy acceptance test: repack the jar for acc environment (replacing datasource.properties etc)
deploy uat test: repack the jar for uat environment (replacing datasource.properties etc)

I don't want to build the jar from scratch for different environments as it wastes time and potentially has risk of building inconsistent artifacts. For traditional war project, I just extract the war, replace the config files and repack. But this time with spring boot, somehow it does not work. When I run the repacked jar, it reports

java.lang.IllegalStateException: Unable to open nested entry 'lib/antlr-2.7.7.jar'. It has been compressed and nested jar files must be stored without compression. Please check the mechanism used to create your executable jar file
    at org.springframework.boot.loader.jar.JarFile.createJarFileFromFileEntry(JarFile.java:378)
    at org.springframework.boot.loader.jar.JarFile.createJarFileFromEntry(JarFile.java:355)
    at org.springframework.boot.loader.jar.JarFile.getNestedJarFile(JarFile.java:341)
    at org.springframework.boot.loader.archive.JarFileArchive.getNestedArchive(JarFileArchive.java:108)
    at org.springframework.boot.loader.archive.JarFileArchive.getNestedArchives(JarFileArchive.java:92)
    at org.springframework.boot.loader.ExecutableArchiveLauncher.getClassPathArchives(ExecutableArchiveLauncher.java:68)
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:60)
    at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:45)

I extracted the origin jar and the repacked jar and don't find differences with lib folder.

task extractArtifact() {
    doLast {

        def outputDirName = "${buildDir}/tmp/under_config"
        def outputDir = file(outputDirName)
        assert outputDir.deleteDir()  // cleanup workspace

        def zipFile = file("${buildDir}/libs/${getArtifactName()}")

        copy {
            from zipTree(zipFile)
            into outputDir
        }

        copy {
            from file("${buildDir}/env")
            into file("${buildDir}/tmp/under_config")
        }

    }
}

task repackConfiguredArtifact(type: Zip, dependsOn: extractArtifact)  {
    archiveName = "${getArtifactName()}"
    destinationDir = file("${buildDir}/libs/${getEnv()}")
    from file("${buildDir}/tmp/under_config")
}

Does anyone have an idea?

Or how do you guys config the jar for different environment (without re-compile the binary).

Answer 1

You shoud add -0 to store only; use no ZIP compression

$jar -cvf0m yourproject.jar META-INF/MANIFEST.MF .

There is another soulution: Set the active Spring profiles

$java -jar -Dspring.profiles.active=production demo-0.0.1-SNAPSHOT.jar

You can use application-${profile}.properties to specify profile-specific values.

Answer 2

I have a solution after looking up the spring-boot reference.

1. turn default spring boot repackage off since I need to repack it anyway.

2. extract the traditional jar and copy the config files

3. Use jar type task to repack it
4. Use BootRepackage type task to assemble a spring-boot jar.

here is the code:

bootRepackage {
    enabled = false
}

task extractArtifact() {
    doLast {

        def outputDirName = "${buildDir}/tmp/under_config"
        def outputDir = file(outputDirName)
        assert outputDir.deleteDir()  // cleanup workspace

        def zipFile = file("${buildDir}/libs/${getArtifactName()}")

        copy {
            from zipTree(zipFile)
            into outputDir
        }

        copy {
            from file("${buildDir}/env")
            into file("${buildDir}/tmp/under_config")
        }

        assert zipFile.delete()
    }
}

task clientJar(type: Jar, dependsOn: extractArtifact) {
    archiveName = "${getArtifactName()}"
    from file("${buildDir}/tmp/under_config")
}

task repackConfiguredArtifact(type: BootRepackage, dependsOn: clientJar) {
    withJarTask = clientJar
}