Support exporting jar

jdtls.ext/com.microsoft.jdtls.ext.core/plugin.xml

@@ -7,6 +7,7 @@
             <command id="java.project.list"/>
             <command id="java.getPackageData"/>
             <command id="java.resolvePath" />
+            <command id="java.project.getMainMethod" />
         </delegateCommandHandler>
     </extension>
     <extension

jdtls.ext/com.microsoft.jdtls.ext.core/src/com/microsoft/jdtls/ext/core/CommandHandler.java

@@ -31,6 +31,8 @@ public Object executeCommand(String commandId, List<Object> arguments, IProgress
                     return PackageCommand.getChildren(arguments, monitor);
                 case "java.resolvePath":
                     return PackageCommand.resolvePath(arguments, monitor);
+                case "java.project.getMainMethod":
+                    return ProjectCommand.getMainMethod(monitor);
                 default:
                     break;
             }

jdtls.ext/com.microsoft.jdtls.ext.core/src/com/microsoft/jdtls/ext/core/ProjectCommand.java

@@ -19,9 +19,25 @@
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IWorkspaceRoot;
 import org.eclipse.core.resources.ResourcesPlugin;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.jdt.core.JavaCore;
+import org.eclipse.jdt.core.JavaModelException;
+import org.eclipse.jdt.core.IMethod;
+import org.eclipse.jdt.core.IJavaProject;
+import org.eclipse.jdt.core.IModuleDescription;
+import org.eclipse.jdt.core.search.IJavaSearchScope;
+import org.eclipse.jdt.core.search.SearchEngine;
+import org.eclipse.jdt.core.search.SearchPattern;
+import org.eclipse.jdt.core.search.IJavaSearchConstants;
+import org.eclipse.jdt.core.search.SearchRequestor;
+import org.eclipse.jdt.core.search.SearchMatch;
+import org.eclipse.jdt.core.search.SearchParticipant;
+import org.eclipse.jdt.launching.JavaRuntime;
 import org.eclipse.jdt.ls.core.internal.JavaLanguageServerPlugin;
 import org.eclipse.jdt.ls.core.internal.ProjectUtils;
 import org.eclipse.jdt.ls.core.internal.ResourceUtils;
@@ -33,6 +49,18 @@
 
 public final class ProjectCommand {
 
+    public static class MainClassInfo {
+
+        public String name;
+
+        public String path;
+
+        public MainClassInfo(String name, String path) {
+            this.name = name;
+            this.path = path;
+        }
+    }
+
     public static List<PackageNode> listProjects(List<Object> arguments, IProgressMonitor monitor) {
         String workspaceUri = (String) arguments.get(0);
         IPath workspacePath = ResourceUtils.canonicalFilePathFromURI(workspaceUri);
@@ -79,4 +107,61 @@ private static String getWorkspaceInvisibleProjectName(IPath workspacePath) {
         String fileName = workspacePath.toFile().getName();
         return fileName + "_" + Integer.toHexString(workspacePath.toPortableString().hashCode());
     }
+
+    public static List<MainClassInfo> getMainMethod(IProgressMonitor monitor) {
+        final List<MainClassInfo> res = new ArrayList<>();
+        IJavaSearchScope scope = SearchEngine.createWorkspaceScope();
+        SearchPattern pattern = SearchPattern.createPattern("main(String[]) void", IJavaSearchConstants.METHOD,
+                IJavaSearchConstants.DECLARATIONS, SearchPattern.R_EXACT_MATCH | SearchPattern.R_CASE_SENSITIVE);
+        SearchRequestor requestor = new SearchRequestor() {
+            @Override
+            public void acceptSearchMatch(SearchMatch match) {
+                Object element = match.getElement();
+                if (element instanceof IMethod) {
+                    IMethod method = (IMethod) element;
+                    try {
+                        if (method.isMainMethod()) {
+                            IResource resource = method.getResource();
+                            if (resource == null) {
+                                return;
+                            }
+                            IJavaProject javaProject = method.getJavaProject();
+                            if (javaProject == null) {
+                                return;
+                            }
+                            String mainClass = method.getDeclaringType().getFullyQualifiedName();
+                            String filePath = null;
+                            if (match.getResource() instanceof IFile) {
+                                filePath = match.getResource().getLocation().toOSString();
+                            }
+                            res.add(new MainClassInfo(mainClass, filePath));
+                        }
+                    } catch (JavaModelException e) {
+                        return;
+                    }
+                }
+            }
+        };
+        SearchEngine searchEngine = new SearchEngine();
+        try {
+            searchEngine.search(pattern, new SearchParticipant[] {SearchEngine.getDefaultSearchParticipant()},
+                    scope, requestor, new NullProgressMonitor());
+        } catch (Exception e) {
+            // ignore
+        }
+        return res;
+    }
+
+    public static String getModuleName(IJavaProject project) {
+        if (project == null || !JavaRuntime.isModularProject(project)) {
+            return null;
+        }
+        try {
+            IModuleDescription module = project.getModuleDescription();
+            return module == null ? null : module.getElementName();
+        } catch (CoreException e) {
+            return null;
+        }
+    }
+
 }