Develop Reference

JDBC Driver is found when doing UT, but not when the jar is compiled

I was trying to set up a JDBC connection to a redshift database in my java code and created a few UTs that would make calls to that database using the driver.
The problem lies (probably) in my Gradle as a classpath problem, as the UTs runs fine, but when I'm deploying the jar on my server, suddenly I get:
java.lang.ClassNotFoundException: com.amazon.redshift.jdbc42.Driver
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
Here is my function :
private void establishJDBCConnection() throws Exception {
Class.forName("com.amazon.redshift.jdbc42.Driver");
Properties props = new Properties();
props.setProperty("user", USERNAME);
props.setProperty("password", PWD);
conn = DriverManager.getConnection(DB_URL, props);
}
And here is my gradle files (I've tried reducing them, but I don't know much about which parts are important so it may still be a bit big)
We are running with gradle 5.2.1
build.gradle:
apply plugin: 'java'
apply plugin: 'osgi'
apply plugin: 'partnerextension'
group = 'com.stuff'
// Setup of version, dependencies, imports, names...
version = '3.9.0.14'
// Repositories for the script itself (STIBO Added)
buildscript {
repositories{
repositories {
mavenCentral()
maven {
url "https://artifactory-2018.schneider-electric.com/artifactory/oneoffer-oim-libs-step9.3"
}
maven {
url "https://s3.amazonaws.com/redshift-maven-repository/release"
}
}
dependencies {
classpath 'com.stibo:com.stibo.gradle.plugin.partnerextension:1.0.0'
}
}
}
// Repositories for the project
repositories {
mavenCentral()
maven {
url "https://artifactory-2018.schneider-electric.com/artifactory/oneoffer-oim-libs-step9.3"
}
maven {
url "https://s3.amazonaws.com/redshift-maven-repository/release"
}
}
jar {
baseName = "com.stuff-${version}"
manifest {
// Do not export anything from the bundle
instruction 'Export-Package', "!*"
}
}
apply from :'partner.gradle'
partner.gradle:
// Setup of version, dependencies, imports, names...
def artifactName
// added so to declare external component POI
configurations {
includeInJar
}
dependencies {
testCompile 'junit:junit:4.12'
testCompile "org.mockito:mockito-core:2.18.3"
//compile group: 'com.amazon.redshift', name: 'redshift-jdbc42', version: '1.2.43.1067'
compile group: 'com.amazon.redshift', name: 'redshift-jdbc42-no-awssdk', version: '1.2.8.1005'
compile group: 'com.amazonaws', name: 'aws-java-sdk-redshift', version: '1.11.920'
// added to declare POI
includeInJar 'some jars', \/* , \
'com.amazon.redshift:redshift-jdbc42:1.2.43.1067'*/
configurations.compile.extendsFrom(configurations.includeInJar)
}
jar {
into('lib') {
println "includeInJar: " + configurations.includeInJar.collect { File file -> file }
from configurations.includeInJar
}
// generate checksum
def folder = new File( "${buildDir}")
if( !folder.exists() ) {
// Create all folders up-to and including B
folder.mkdirs()
}
manifest {
def jarName = "com.stuff"
instruction 'Bundle-ClassPath', \
'somejars'/*, \
'lib/redshift-jdbc42-1.2.43.1067.jar' */
instruction 'Import-Package',
'''someimports'''
archiveName = "${jarName}-${version}.jar"
artifactName = archiveName
}
}
I've tried adding the redshift driver jar to my generated jar, but that does not make the class available. I've tried adding a main that would run this function and use the -cp to add the driver-jar to my classpath, but it didn't work either.
I've tried using the PostgreSQL driver instead of redshift, didn't work.
Also, can anyone explain to me how can the code work fine during UT? it makes no sense to me!

Protobuf plugin for gradle does not generate service class

I try to build a gRPC and protobuf application in java with Gradle
I followed the instruction from: https://github.com/grpc/grpc-java/blob/master/README.md
The issue is that one file is not generated: *ServiceGrpc.java
But the corresponding *ServiceGrpc.class file is in the build directory generated by the gradle build.
I tried with running the compiler manually with the command protoc but I have the exact same issue (I'm on Ubuntu 18.04)
Here is my proto file
syntax = "proto3";
option java_multiple_files=true;
option java_generic_services= true;
//...//
message Track {
int64 id = 1; //... }
service TrackService {
rpc Create(Track) returns (Response); }
//...
The file Track.java, TrackOrBuilder.java, TrackOuterClass.java are all there. As well as their corresponding .class files in the build directory.
With the flag "option java_generic_services= true", TrackService.java is generated, and again .class file.
But not matter what, the file TrackServiceGrpc.java is not created, contrary its correspond .class file, which is quite confusing.
here is my build.gradle :
buildscript {
repositories {
mavenCentral()
}
dependencies {
classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.8'
}
}
plugins {
id 'java'
}
repositories {
mavenCentral()
}
apply plugin: 'com.google.protobuf'
protobuf {
protoc {
artifact = "com.google.protobuf:protoc:3.9.0"
generateProtoTasks.generatedFilesBaseDir = 'src'
}
plugins {
grpc {
artifact = 'io.grpc:protoc-gen-grpc-java:1.23.0'
}
}
generateProtoTasks {
all()*.plugins {
grpc {}
}
}
}
dependencies {
testCompile group: 'junit', name: 'junit', version: '4.12'
//https://github.com/grpc/grpc-java/blob/master/README.md
implementation 'io.grpc:grpc-netty-shaded:1.23.0'
implementation 'io.grpc:grpc-protobuf:1.23.0'
implementation 'io.grpc:grpc-stub:1.23.0'
compile group: 'javax.annotation', name: 'javax.annotation-api', version: '1.3.2'
}
What am I doing wrong ?

If the .class file for the gRPC service exists, the corresponding .java file must have been at some place. By default, it should appear in $generatedFilesBaseDir/{main, test}/grpc. By default, $generatedFilesBaseDir is $buildDir/generated/source/proto. But seems you have changed (or intended to change) generatedFilesBaseDir, that configuration should be done inside the protobuf closure instead of the protoc closure.
protobuf {
protoc {
artifact = "com.google.protobuf:protoc:3.9.0"
}
plugins {
grpc {
artifact = 'io.grpc:protoc-gen-grpc-java:1.23.0'
}
}
generatedFilesBaseDir = 'src'
generateProtoTasks {
all()*.plugins {
grpc {}
}
}
}
Also, need to mention that configuring generatedFileBaseDir is discouraged as it might have potential problems. See discussion at https://github.com/google/protobuf-gradle-plugin/issues/332

How to create JAR from specific classes and use it with Gradle?

I have few Java classes that I want to use on different projects.
I don't want to move these classes in a dedicated project for now.
So I want to build a JAR with these classes, and be able to use it in my other projects, all with Gradle.
So here my JAR task (sources) and I publish it as an artifact :
task utilitiesJar(type: Jar) {
baseName = 'utilities'
version = '0.0.1'
includeEmptyDirs = false
from sourceSets.main.allJava
include "**\\common\\exceptions\\**"
include "**\\common\\json\\**"
include "**\\common\\logging\\**"
}
publishing {
publications {
utilities(MavenPublication) {
artifact utilitiesJar
groupId group
artifactId utilitiesJar.baseName
version utilitiesJar.version
}
}
repositories {
maven {
url 'my_URL'
}
}
}
I get it back with an other project :
repositories {
mavenCentral()
maven {
url 'my_URL'
}
}
...
compile (...)
...
Seems like the JAR is correctly imported (I can see it in "External Libraries" of IntelliJ, with all its classes), but I can't use it.
Maybe because the .class files are missing ?
I'm beginner in Java, maybe I missed something.
How can I create a JAR with only some classes and then use it ?

Ok so as said in comments, I have to include the builded .class files, I can't use external .java classes like this.
So my solution :
def utilitiesName = '...'
def utilitiesVersion = '0.0.1'
task utilitiesJar(type: Jar, dependsOn: classes) {
baseName = utilitiesName
version = utilitiesVersion
includeEmptyDirs = false
from sourceSets.main.output
include ("**\\common\\exceptions\\**\\*", "**\\common\\json\\**\\*", "**\\common\\logging\\**\\*")
}
task utilitiesSourcesJar(type: Jar, dependsOn: classes) {
baseName = utilitiesName
version = utilitiesVersion
classifier = 'sources'
includeEmptyDirs = false
from sourceSets.main.allJava
include ("**\\common\\exceptions\\**\\*", "**\\common\\json\\**\\*", "**\\common\\logging\\**\\*")
}
publishing {
publications {
utilities(MavenPublication) {
artifact utilitiesJar
artifact utilitiesSourcesJar
groupId group
artifactId utilitiesName
version utilitiesVersion
}
}
repositories {
maven {
url 'myURL'
}
}
}
Now I can use it and see the classes in my IDE.
PS : doing in this way is pretty dirty. Create a sub-project / a module, it's just the way how to do it, that's finaly what I did.

Creating correct Maven dependencies from Gradle

After some hours of search and research I came up with a working example for writing the correct Maven dependencies into the generated pom.xml when using Gradle 1.11 and maven-publish plugin.
The first problem I faced was the provided dependency that always was written as runtime into the pom.xml
The second problem was the dynamic version, that I use for minor version changes. Maven and Gradle have different notations and the maven-publish simply writes the Gradle kind of notation into the pom.xml
Here is my example:
apply plugin: 'java'
apply plugin: 'maven-publish'
group = 'de.pentos'
version = '0.4.4'
sourceCompatibility = 1.7
repositories {
mavenCentral()
mavenLocal()
}
configurations {
provided
compile.extendsFrom provided
}
dependencies {
provided("org.projectlombok:lombok:1.+")
provided("javax.servlet:javax.servlet-api:3.1.0")
compile("org.slf4j:slf4j-api:1.7+")
compile("com.fasterxml.jackson.core:jackson-databind:2.3.+")
compile("joda-time:joda-time:2.3+")
compile("org.springframework:spring-webmvc:3.2+")
compile("org.springframework.security:spring-security-web:3.1+")
testCompile("junit:junit:4.11")
}
jar { baseName = "${project.group}.${project.name}" }
publishing {
publications {
jar(MavenPublication) {
from components.java
artifactId "${project.name}"
artifact sourceJar { classifier "sources" }
pom.withXml {
final Node root = asNode()
final versionPattern = ~/(?:(.+)\.)?(.+?)\.?\+/
configurations.compile.allDependencies.each {
final name = it.name
final group = it.group
final m = versionPattern.matcher(it.version)
if (m.matches()) {
final base = m[0][1]
final rest = m[0][2].toInteger()
final version = '[' + (base ? base + '.' : '') + (rest) + ',' + (base ? base + '.' : '') + (rest + 1) + ')'
root.dependencies.first().findAll{
it.groupId.first().value()[0] == group && it.artifactId.first().value()[0] == name
}.each {
it.version.first().value = version
}
}
}
configurations.provided.allDependencies.each {
final name = it.name
final group = it.group
root.dependencies.first().findAll{
it.groupId.first().value()[0] == group && it.artifactId.first().value()[0] == name
}.each {
it.scope.first().value = 'provided'
}
}
}
}
}
}
tasks.withType(Compile) { options.encoding = 'UTF-8' }
task sourceJar(type: Jar) {
classifier = 'sources'
from sourceSets.main.allSource
}
So what is my Question?
I had some trouble with a lot examples that simply compared
..findAll {
it.groupId == group
}
This hadn't worked for me and I had to find out by lot of testing how to get the findAll to work.
So is my version to detailed? Can it be written with less code?
Can I extract the functionality for dependency management into a more system wide script, that can be reused from all other projects, that need this dependency management? How?
During compileJava I get the warning :compileJavawarning: [options] bootstrap class path not set in conjunction with -source 1.7
What does this mean, and how can I fix that.

I had some trouble with a lot examples that simply compared [...]
it.groupId is not a String. You'll need something like it.groupId.value(), or perhaps it.groupId[0].value().
Can I extract the functionality for dependency management into a more system wide script, that can be reused from all other projects, that need this dependency management? How?
You can write a plugin class, and ship it to builds as a Jar. For details, see the Gradle User Guide.
During compileJava I get the warning :compileJavawarning: [options] bootstrap class path not set in conjunction with -source 1.7
What does this mean, and how can I fix that.
This question has been asked and answered many times already. See Stack Overflow or http://forums.gradle.org.
PS: Instead of rewriting Ivy to Maven version range syntax, it should be possible to use Maven syntax from the start (i.e. in the build script).

Gradle scala class already defined with combined Java compilation

I have the following scala compilation issue
scala -> depends upon java source
java source -> depends upon scala source
My scala code is in src/main/scala
My java code is in src/main/java
I cant change this code so I need to compile this with gradle and it currently compiles with JRuby just fine.
I have read the following posts on how to solve this issue:
http://forums.gradle.org/gradle/topics/how_to_compile_a_java_class_that_depends_on_a_scala_class_in_gradle
http://forums.gradle.org/gradle/topics/how_to_compile_a_java_class_that_depends_on_a_scala_class_in_gradle
I added this to my build:
ext {
baseName = 'd2'
description = 'Divisional IVR.'
combinedSources = "$buildDir/combined-sources"
}
apply plugin: 'scala'
compileScala.taskDependencies.values = compileScala.taskDependencies.values - 'compileJava'
compileJava.dependsOn compileScala
sourceSets.main.scala.srcDir "$combinedSources"
sourceSets.main.java.srcDirs = []
I tried to copy all the scala and java files to one location:
compileScala.dependsOn{
copyAllSourceFiles
}
task copyAllSourceFiles(type:Copy) {
description = 'Copy All Source Files.'
from('src/main/java') {}
from('/src/main/scala') {}
into combinedSources
includeEmptyDirs = false
}
But now I get an error:
[ant:scalac] Compiling 18 source files to C:\usr\git_workspaces\xivr\d2\target\classes\main
[ant:scalac] Compiling 18 scala and 196 java source files to C:\usr\git_workspaces\xivr\d2\target\classes\main
[ant:scalac] C:\usr\git_workspaces\xivr\d2\target\combined-sources\com\comcast\ivr\d2\actors\AlternateAniWithAccountActor.scala:9: error: AlternateAniWithAccountActor is already defined as class AlternateAniWithAccountActor
It almsot seems like scalaCompile sees $combinedSources and 'src/main/scala'

It almsot seems like scalaCompile sees $combinedSources and 'src/main/scala'
That's how you configured it: src/main/scala is the default, and you added "$combinedSources". To override the default, use sourceSets.main.scala.srcDirs = [combinedSources].
In any case, you don't have to (and shouldn't) copy sources around. Here is one solution that neither requires copying nor reconfiguring of task dependencies:
sourceSets.main.scala.srcDir "src/main/java"
sourceSets.main.java.srcDirs = []
Now, your Java and Scala code will get joint-compiled, and can depend on each other arbitrarily.
PS: Instead of "$combinedSources", use combinedSources.

gradle.properties
theVersion=2.1
theSourceCompatibility=1.7
theScalaVersion=2.10.3
build.gradle
apply {
plugin 'scala'
plugin 'java'
plugin 'idea'
}
ext {
scalaVersion = theScalaVersion
}
sourceCompatibility = theSourceCompatibility
tasks.withType(ScalaCompile) {
scalaCompileOptions.useAnt = false
}
dependencies {
compile "org.scala-lang:scala-library:$theScalaVersion"
compile "org.scala-lang:scala-compiler:$theScalaVersion"
}
sourceSets {
main.scala.srcDirs = ["src/main/scala", "src/main/java"]
main.java.srcDirs = []
}