Can get VM installation path through ProjectCommand.getProjectSettings()

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/commands/ProjectCommand.java

@@ -13,6 +13,7 @@
 
 package org.eclipse.jdt.ls.core.internal.commands;
 
+import java.io.File;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.ArrayList;
@@ -41,7 +42,9 @@
 import org.eclipse.jdt.core.JavaCore;
 import org.eclipse.jdt.core.JavaModelException;
 import org.eclipse.jdt.internal.core.ClasspathEntry;
+import org.eclipse.jdt.launching.IVMInstall;
 import org.eclipse.jdt.launching.JavaLaunchDelegate;
+import org.eclipse.jdt.launching.JavaRuntime;
 import org.eclipse.jdt.ls.core.internal.IConstants;
 import org.eclipse.jdt.ls.core.internal.JDTUtils;
 import org.eclipse.jdt.ls.core.internal.JavaLanguageServerPlugin;
@@ -51,6 +54,7 @@
 
 public class ProjectCommand {
 
+	public static final String VM_LOCATION = IConstants.PLUGIN_ID + ".vm.location";
 	private static final String TEST_SCOPE_VALUE = "test";
 
 	/**
@@ -61,7 +65,9 @@ public class ProjectCommand {
 	 * @param settingKeys
 	 *                        the settings we want to query, for example:
 	 *                        ["org.eclipse.jdt.core.compiler.compliance",
-	 *                        "org.eclipse.jdt.core.compiler.source"]
+	 *                        "org.eclipse.jdt.core.compiler.source"].
+	 *                        Besides the options defined in JavaCore, the following keys can also be used:
+	 *                        - "org.eclipse.jdt.ls.core.vm.location": Get the location of the VM assigned to build the given Java project
 	 * @return A <code>Map<string, string></code> with all the setting keys and
 	 *         their values.
 	 * @throws CoreException
@@ -71,7 +77,22 @@ public static Map<String, String> getProjectSettings(String uri, List<String> se
 		IJavaProject javaProject = getJavaProjectFromUri(uri);
 		Map<String, String> settings = new HashMap<>();
 		for (String key : settingKeys) {
-			settings.putIfAbsent(key, javaProject.getOption(key, true));
+			switch(key) {
+				case VM_LOCATION:
+					IVMInstall vmInstall = JavaRuntime.getVMInstall(javaProject);
+					if (vmInstall == null) {
+						continue;
+					}
+					File location = vmInstall.getInstallLocation();
+					if (location == null) {
+						continue;
+					}
+					settings.putIfAbsent(key, location.getAbsolutePath());
+					break;
+				default:
+					settings.putIfAbsent(key, javaProject.getOption(key, true));
+					break;
+			}
 		}
 		return settings;
 	}

org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/commands/ProjectCommandTest.java

@@ -18,13 +18,16 @@
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
+import java.io.File;
 import java.net.URI;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
 import org.eclipse.core.resources.IProject;
 import org.eclipse.jdt.core.IJavaProject;
+import org.eclipse.jdt.launching.IVMInstall;
+import org.eclipse.jdt.launching.JavaRuntime;
 import org.eclipse.jdt.ls.core.internal.WorkspaceHelper;
 import org.eclipse.jdt.ls.core.internal.commands.ProjectCommand.ClasspathOptions;
 import org.eclipse.jdt.ls.core.internal.commands.ProjectCommand.ClasspathResult;
@@ -62,11 +65,26 @@ public void testGetProjectSettingsForMavenJava8() throws Exception {
         assertEquals("1.8", options.get("org.eclipse.jdt.core.compiler.source"));
     }
 
+    @Test
+    public void testGetProjectVMInstallation() throws Exception {
+        importProjects("maven/salut2");
+        IProject project = WorkspaceHelper.getProject("salut2");
+        String uriString = project.getFile("src/main/java/foo/Bar.java").getLocationURI().toString();
+        List<String> settingKeys = Arrays.asList(ProjectCommand.VM_LOCATION);
+        Map<String, String> options = ProjectCommand.getProjectSettings(uriString, settingKeys);
+
+        IJavaProject javaProject = ProjectCommand.getJavaProjectFromUri(uriString);
+        IVMInstall vmInstall = JavaRuntime.getVMInstall(javaProject);
+        assertNotNull(vmInstall);
+        File location = vmInstall.getInstallLocation();
+        assertNotNull(location);
+        assertEquals(location.getAbsolutePath(), options.get(ProjectCommand.VM_LOCATION));
+    }
+
     @Test
     public void testGetProjectFromUri() throws Exception {
         importProjects("maven/salut");
         IProject project = WorkspaceHelper.getProject("salut");
-
         String javaSource = project.getFile("src/main/java/Foo.java").getLocationURI().toString();
         IJavaProject javaProject = ProjectCommand.getJavaProjectFromUri(javaSource);
         assertNotNull("Can get project from java file uri", javaProject);