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

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.
turn default spring boot repackage off since I need to repack it anyway.
extract the traditional jar and copy the config files
Use jar type task to repack it
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
}

Answer 3

I found that if you had a directory called 'resources/lib' the spring-boot executable JAR would assume the contents were zipped and throw the above exception. Renaming to 'resources/static' worked for me.