Filter files matching files.exclude from project

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

@@ -4,6 +4,7 @@
 <extension point="org.eclipse.jdt.ls.core.delegateCommandHandler">
         <delegateCommandHandler class="com.microsoft.jdtls.ext.core.CommandHandler">
             <command id="java.project.list"/>
+            <command id="java.project.updateFilters"/>
             <command id="java.getPackageData"/>
             <command id="java.resolvePath" />
         </delegateCommandHandler>

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

@@ -25,6 +25,8 @@ public Object executeCommand(String commandId, List<Object> arguments, IProgress
             switch (commandId) {
                 case "java.project.list":
                     return ProjectCommand.execute(arguments, monitor);
+                case "java.project.updateFilters":
+                    return ProjectCommand.updateFilters(arguments, monitor);
                 case "java.getPackageData":
                     return PackageCommand.getChildren(arguments, monitor);
                 case "java.resolvePath":

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

@@ -13,10 +13,17 @@
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
+import java.util.Set;
+import java.util.stream.Collectors;
 
+import org.eclipse.core.resources.FileInfoMatcherDescription;
 import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.resources.IResourceFilterDescription;
 import org.eclipse.core.resources.IWorkspaceRoot;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.IPath;
@@ -47,6 +54,44 @@ public static List<PackageNode> execute(List<Object> arguments, IProgressMonitor
         return children;
     }
 
+    @SuppressWarnings("unchecked")
+    public static boolean updateFilters(List<Object> arguments, IProgressMonitor monitor) throws Exception {
+        final Set<String> patterns = new HashSet<>((List<String>) arguments.get(0));
+        final IProject[] projects = getWorkspaceRoot().getProjects();
+        final Set<IProject> filterUpdated = new HashSet<>();
+        for (final IProject project : projects) {
+            if (!project.exists()) {
+                continue;
+            }
+            final Map<String, IResourceFilterDescription> filters = Arrays.stream(project.getFilters()).collect(Collectors.toMap(
+                filter -> (String) filter.getFileInfoMatcherDescription().getArguments(), filter -> filter
+            ));
+            for (final String pattern: patterns) { // Handle newly added filters
+                if (filters.containsKey(pattern)) {
+                    continue;
+                }
+                project.createFilter(
+                    IResourceFilterDescription.EXCLUDE_ALL |
+                    IResourceFilterDescription.FILES |
+                    IResourceFilterDescription.FOLDERS |
+                    IResourceFilterDescription.INHERITABLE,
+                    new FileInfoMatcherDescription("org.eclipse.core.resources.regexFilterMatcher", pattern), 0, monitor);
+                filterUpdated.add(project);
+            }
+            for (final String pattern: filters.keySet()) { // Handle deleted filters
+                if (patterns.contains(pattern)) {
+                    continue;
+                }
+                filters.get(pattern).delete(0, monitor);
+                filterUpdated.add(project);
+            }
+            if (filterUpdated.contains(project)) { // Refresh the hierachy if filter is updated
+                project.refreshLocal(IResource.DEPTH_INFINITE, monitor);
+            }
+        }
+        return filterUpdated.size() > 0;
+    }
+
     private static IWorkspaceRoot getWorkspaceRoot() {
         return ResourcesPlugin.getWorkspace().getRoot();
     }