Could not determine java version

Thad_Humphries · January 26, 2019, 6:06pm

I am trying to build several older projects in Eclipse 2018-12 (4.10.0) with the the Gradle wrapper. All these projects use Gradle 2.14.1. My JAVA_HOME is set for Java 8, using Amazon Corretto 1.8.0_202-b08. Everything is fine from the command line. However from Eclipse I get the error

Could not create an instance of Tooling API implementation using the specified Gradle distribution 'https://services.gradle.org/distributions/gradle-2.14.1-all.zip'.
Could not create service of type FileWatcherFactory using GlobalScopeServices.createFileWatcherFactory().
Could not determine java version from '11.0.1'.

Buildship 3.0.1v20181217-1554 is installed. I have tried both gradle-2.14.1-all.zip and gradle-2.14.1-bin.zip

Yes, Java 11.0.1 is also installed, but it is not JAVA_HOME or in the PATH (or even set in this Eclipse workspace). Everything in this workspace is Java 8, usually targeting Java 6 or 7.

Is Gradle forcing an upgrade to or an uninstall of Java 11? Java 11 is needed for other things, but we have no interest in moving these projects to it now that Amazon has stepped up to supporting Java 8. Likewise we have no interest in moving these projects to a newer wrapper. We went through too much pain trying to keep up with 2.X and all that broke at it changed to suddenly jump to v4 or v5.

Lance · January 26, 2019, 7:55pm

Here’s the oldest version of JavaVersion.java that I could find on github

github.com

gradle/gradle/blob/v3.0.0/subprojects/base-services/src/main/java/org/gradle/api/JavaVersion.java#L93


// For testing current() method
static void resetCurrent() {
    currentJavaVersion = null;
}


public static JavaVersion forClassVersion(int classVersion) {
    int index = classVersion - 45; //class file versions: 1.1 == 45, 1.2 == 46...
    if (index >= 0 && index < values().length) {
        return values()[index];
    }
    throw new IllegalArgumentException(String.format("Could not determine java version from '%d'.", classVersion));
}


public static JavaVersion forClass(byte[] classData) {
    if (classData.length<8) {
        throw new IllegalArgumentException("Invalid class format. Should contain at least 8 bytes");
    }
    return forClassVersion(classData[7] & 0xFF);
}


public boolean isJava5() {

You might be able to fool gradle into thinking you’re on an older version of java by passing

-Djava.version=1.9

Warning: Its quite possible that your old version of Gradle won’t work with java 11. It might be time to upgrade