Support exporting jar with custom task

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

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

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

@@ -31,8 +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(arguments, monitor);
+                case "java.project.getMainClasses":
+                    return ProjectCommand.getMainClasses(arguments, monitor);
                 case "java.project.generateJar":
                     return ProjectCommand.exportJar(arguments, monitor);
                 default:

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

@@ -67,9 +67,7 @@
 public final class ProjectCommand {
 
     private static class MainClassInfo {
-
         public String name;
-
         public String path;
 
         public MainClassInfo(String name, String path) {
@@ -78,6 +76,12 @@ public MainClassInfo(String name, String path) {
         }
     }
 
+    private static class Classpath {
+        public String source;
+        public String destination;
+        public boolean isArtifact;
+    }
+
     private static class ExportResult {
         public boolean result;
         public String message;
@@ -150,25 +154,21 @@ public static ExportResult exportJar(List<Object> arguments, IProgressMonitor mo
         if (arguments.size() < 3) {
             return new ExportResult(false, "Invalid export Arguments");
         }
-        String mainMethod = gson.fromJson(gson.toJson(arguments.get(0)), String.class);
-        String[] classpaths = gson.fromJson(gson.toJson(arguments.get(1)), String[].class);
+        String mainClass = gson.fromJson(gson.toJson(arguments.get(0)), String.class);
+        Classpath[] classpaths = gson.fromJson(gson.toJson(arguments.get(1)), Classpath[].class);
         String destination = gson.fromJson(gson.toJson(arguments.get(2)), String.class);
         Manifest manifest = new Manifest();
         manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0");
-        if (mainMethod.length() > 0) {
-            manifest.getMainAttributes().put(Attributes.Name.MAIN_CLASS, mainMethod);
+        if (mainClass.length() > 0) {
+            manifest.getMainAttributes().put(Attributes.Name.MAIN_CLASS, mainClass);
         }
         try (JarOutputStream target = new JarOutputStream(new FileOutputStream(destination), manifest)) {
             Set<String> directories = new HashSet<>();
-            for (String classpath : classpaths) {
-                if (classpath != null) {
-                    if (classpath.endsWith(".jar")) {
-                        ZipFile zip = new ZipFile(classpath);
-                        writeArchive(zip, true, true, target, directories, monitor);
-                    } else {
-                        File folder = new File(classpath);
-                        writeFileRecursively(folder, target, directories, folder.getAbsolutePath().length() + 1);
-                    }
+            for (Classpath classpath : classpaths) {
+                if (classpath.isArtifact) {
+                    writeArchive(new ZipFile(classpath.source), true, true, target, directories, monitor);
+                } else {
+                    writeFile(new File(classpath.source), new Path(classpath.destination), true, true, target, directories);
                 }
             }
         } catch (Exception e) {
@@ -177,23 +177,7 @@ public static ExportResult exportJar(List<Object> arguments, IProgressMonitor mo
         return new ExportResult(true);
     }
 
-    private static void writeFileRecursively(File folder, JarOutputStream jarOutputStream, Set<String> directories,
-            int len) {
-        File[] files = folder.listFiles();
-        for (File file : files) {
-            if (file.isDirectory()) {
-                writeFileRecursively(file, jarOutputStream, directories, len);
-            } else if (file.isFile()) {
-                try {
-                    writeFile(file, new Path(file.getAbsolutePath().substring(len)), true, true, jarOutputStream, directories);
-                } catch (Exception e) {
-                    // do nothing
-                }
-            }
-        }
-    }
-
-    public static List<MainClassInfo> getMainMethod(List<Object> arguments, IProgressMonitor monitor) throws Exception {
+    public static List<MainClassInfo> getMainClasses(List<Object> arguments, IProgressMonitor monitor) throws Exception {
         List<PackageNode> projectList = listProjects(arguments, monitor);
         final List<MainClassInfo> res = new ArrayList<>();
         List<IJavaElement> searchRoots = new ArrayList<>();