Separated JDK management code into its own module

Fixes #1857

Author: quintesse

build.gradle

@@ -90,6 +90,8 @@ sourceSets {
 sourceSets.main.compileClasspath += sourceSets.java9.output.classesDirs;
 
 dependencies {
+	implementation project(':jdkmanager')
+
 	implementation 'com.offbytwo:docopt:0.6.0.20150202'
 
 	implementation 'org.apache.commons:commons-text:1.11.0'

jdkmanager/.gitignore

@@ -0,0 +1,22 @@
+.classpath
+.project
+.vscode
+.settings
+target
+.idea
+*.iml
+/build
+.gradle
+.factorypath
+bin
+homebrew-tap
+RESULTS
+*.db
+jbang-action
+out
+node_modules
+package-lock.json
+*.jfr
+itests/hello.java
+*.class
+CHANGELOG.md

jdkmanager/build.gradle

@@ -0,0 +1,31 @@
+plugins {
+	id 'java'
+}
+
+group = 'dev.jbang.jvm'
+version = '0.1.0'
+
+sourceCompatibility = '8'
+targetCompatibility = '8'
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	implementation 'org.apache.commons:commons-compress:1.26.2'
+	implementation 'org.apache.httpcomponents:httpclient:4.5.14'
+	implementation 'org.apache.httpcomponents:httpclient-cache:4.5.14'
+	implementation 'com.google.code.gson:gson:2.11.0'
+
+	implementation "org.slf4j:slf4j-nop:1.7.30"
+	implementation "org.slf4j:jcl-over-slf4j:1.7.30"
+	implementation "org.jspecify:jspecify:1.0.0"
+
+	testImplementation platform('org.junit:junit-bom:5.10.1')
+	testImplementation 'org.junit.jupiter:junit-jupiter'
+}
+
+test {
+	useJUnitPlatform()
+}

jdkmanager/src/main/java/dev/jbang/jvm/Jdk.java

@@ -0,0 +1,122 @@
+package dev.jbang.jvm;
+
+import java.nio.file.Path;
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Set;
+
+import dev.jbang.jvm.util.JavaUtils;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+public interface Jdk extends Comparable<Jdk> {
+    @NonNull JdkProvider getProvider();
+
+    @NonNull String getId();
+
+    @NonNull String getVersion();
+
+    @Nullable Path getHome();
+
+    int getMajorVersion();
+
+    @NonNull Jdk install();
+
+    void uninstall();
+
+    boolean isInstalled();
+
+    class Default implements Jdk {
+        @NonNull private final transient JdkProvider provider;
+        @NonNull private final String id;
+        @NonNull private final String version;
+        @Nullable private final Path home;
+        @NonNull private final Set<String> tags = new HashSet<>();
+
+        Default(
+                @NonNull JdkProvider provider,
+                @NonNull String id,
+                @Nullable Path home,
+                @NonNull String version,
+                @NonNull String... tags) {
+            this.provider = provider;
+            this.id = id;
+            this.version = version;
+            this.home = home;
+        }
+
+        @Override
+        @NonNull
+        public JdkProvider getProvider() {
+            return provider;
+        }
+
+        /** Returns the id that is used to uniquely identify this JDK across all providers */
+        @Override
+        @NonNull
+        public String getId() {
+            return id;
+        }
+
+        /** Returns the JDK's version */
+        @Override
+        @NonNull
+        public String getVersion() {
+            return version;
+        }
+
+        /**
+         * The path to where the JDK is installed. Can be <code>null</code> which means the JDK
+         * isn't currently installed by that provider
+         */
+        @Override
+        @Nullable
+        public Path getHome() {
+            return home;
+        }
+
+        @Override
+        public int getMajorVersion() {
+            return JavaUtils.parseJavaVersion(getVersion());
+        }
+
+        @Override
+        @NonNull
+        public Jdk install() {
+            return provider.install(this);
+        }
+
+        @Override
+        public void uninstall() {
+            provider.uninstall(this);
+        }
+
+        @Override
+        public boolean isInstalled() {
+            return home != null;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) return true;
+            if (o == null || getClass() != o.getClass()) return false;
+            Default jdk = (Default) o;
+            return id.equals(jdk.id) && Objects.equals(home, jdk.home);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(home, id);
+        }
+
+        @Override
+        public int compareTo(Jdk o) {
+            return Integer.compare(getMajorVersion(), o.getMajorVersion());
+        }
+
+        @Override
+        public String toString() {
+            return getMajorVersion() + " (" + version + ", " + id + ", " + home + ")";
+        }
+    }
+}