Bug 531280 : update classpath on module-info.java changes

Change-Id: Ifc524dee7ef516f0bf7e6bd024fb00372ffb46ca
Signed-off-by: Fred Bricon <fbricon@gmail.com>

6 files changed, 153 insertions, 17 deletions

diff --git a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/MavenJdtPlugin.java b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/MavenJdtPlugin.java
index 59cfd023..cc21a0d7 100644
--- a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/MavenJdtPlugin.java
+++ b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/MavenJdtPlugin.java
@@ -97,7 +97,8 @@ public class MavenJdtPlugin extends Plugin {
     File stateLocationDir = getStateLocation().toFile();
 
     this.buildpathManager = new BuildPathManager(projectManager, indexManager, bundleContext, stateLocationDir);
-    workspace.addResourceChangeListener(buildpathManager, IResourceChangeEvent.PRE_DELETE);
+    workspace.addResourceChangeListener(buildpathManager,
+        IResourceChangeEvent.PRE_DELETE | IResourceChangeEvent.POST_CHANGE);
 
     projectManager.addMavenProjectChangedListener(this.buildpathManager);
 
diff --git a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/BuildPathManager.java b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/BuildPathManager.java
index 19790d2a..2667cad9 100644
--- a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/BuildPathManager.java
+++ b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/BuildPathManager.java
@@ -32,6 +32,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
+import java.util.TreeSet;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
@@ -43,7 +45,10 @@ import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResourceChangeEvent;
 import org.eclipse.core.resources.IResourceChangeListener;
+import org.eclipse.core.resources.IResourceDelta;
+import org.eclipse.core.resources.IResourceDeltaVisitor;
 import org.eclipse.core.resources.ResourcesPlugin;
+import org.eclipse.core.resources.WorkspaceJob;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
@@ -51,12 +56,14 @@ import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.SubMonitor;
 import org.eclipse.core.runtime.jobs.Job;
 import org.eclipse.jdt.core.IClasspathAttribute;
 import org.eclipse.jdt.core.IClasspathContainer;
 import org.eclipse.jdt.core.IClasspathEntry;
 import org.eclipse.jdt.core.IJavaModel;
 import org.eclipse.jdt.core.IJavaProject;
+import org.eclipse.jdt.core.IModuleDescription;
 import org.eclipse.jdt.core.IPackageFragmentRoot;
 import org.eclipse.jdt.core.JavaCore;
 import org.eclipse.jdt.core.JavaModelException;
@@ -130,6 +137,8 @@ public class BuildPathManager implements IMavenProjectChangedListener, IResource
 
   final File stateLocationDir;
 
+  final Map<String, Set<String>> requiredModulesMap = new ConcurrentHashMap<String, Set<String>>();
+
   private final DownloadSourcesJob downloadSourcesJob;
 
   private final DefaultClasspathManagerDelegate defaultDelegate;
@@ -589,16 +598,90 @@ public class BuildPathManager implements IMavenProjectChangedListener, IResource
     int type = event.getType();
     if(IResourceChangeEvent.PRE_DELETE == type) {
       // remove custom source and javadoc configuration
-      File attachmentProperties = getSourceAttachmentPropertiesFile((IProject) event.getResource());
+      IProject project = (IProject) event.getResource();
+      File attachmentProperties = getSourceAttachmentPropertiesFile(project);
       if(attachmentProperties.exists() && !attachmentProperties.delete()) {
         log.error("Can't delete " + attachmentProperties.getAbsolutePath()); //$NON-NLS-1$
       }
 
       // remove classpath container state
-      File containerState = getContainerStateFile((IProject) event.getResource());
+      File containerState = getContainerStateFile(project);
       if(containerState.exists() && !containerState.delete()) {
         log.error("Can't delete " + containerState.getAbsolutePath()); //$NON-NLS-1$
       }
+
+      requiredModulesMap.remove(project.getLocation().toString());
+
+    } else if(IResourceChangeEvent.POST_CHANGE == type) {
+
+      IResourceDelta delta = event.getDelta(); // workspace delta
+      IResourceDelta[] resourceDeltas = delta.getAffectedChildren();
+      final Set<IProject> affectedProjects = new LinkedHashSet<IProject>(resourceDeltas.length);
+      ModuleInfoDetector visitor = new ModuleInfoDetector(affectedProjects);
+      for(IResourceDelta d : resourceDeltas) {
+        IProject project = (IProject) d.getResource();
+        if(!ModuleSupport.isMavenJavaProject(project)) {
+          continue;
+        }
+        try {
+          d.accept(visitor, false);
+        } catch(CoreException ex) {
+          log.error(ex.getMessage(), ex);
+        }
+      }
+      if(affectedProjects.isEmpty()) {
+        return;
+      }
+
+      Job job = new WorkspaceJob(Messages.BuildPathManager_update_module_path_job_name) {
+        @Override
+        public IStatus runInWorkspace(IProgressMonitor monitor) {
+          SubMonitor subMonitor = SubMonitor.convert(monitor, affectedProjects.size());
+          for(IProject p : affectedProjects) {
+            if(monitor.isCanceled()) {
+              return Status.CANCEL_STATUS;
+            }
+            if(requiresUpdate(p, subMonitor)) {
+              monitor.setTaskName(p.getName());
+              updateClasspath(p, subMonitor.newChild(1));
+            }
+          }
+          return Status.OK_STATUS;
+        }
+
+        private boolean requiresUpdate(IProject p, IProgressMonitor monitor) {
+          if(!ModuleSupport.isMavenJavaProject(p)) {
+            return false;
+          }
+
+          IJavaProject jp = JavaCore.create(p);
+          try {
+            IModuleDescription moduleDescription = jp.getModuleDescription();
+            if(moduleDescription == null) {
+              return false;
+            }
+            String location = p.getLocation().toString();
+            Set<String> requiredModules = new TreeSet<>(ModuleSupport.getRequiredModules(jp, monitor));
+            if(monitor.isCanceled()) {
+              return false;
+            }
+            // Probably not the best way to detect if module path has changed, like, on the very 1st time a 
+            // module-info.java is modified, there will be no previous state to compare to, but should work 
+            // well enough the rest of the time, for cases that don't involve obscure module path configs
+            Set<String> oldRequiredModules = requiredModulesMap.get(location);
+            if(requiredModules.equals(oldRequiredModules)) {
+              return false;
+            }
+            requiredModulesMap.put(location, requiredModules);
+            return true;
+          } catch(JavaModelException ex) {
+            log.error(ex.getMessage(), ex);
+          }
+          return false;
+        }
+      };
+      job.setRule(MavenPlugin.getProjectConfigurationManager().getRule());
+      job.schedule();
     }
   }
 
@@ -860,4 +943,25 @@ public class BuildPathManager implements IMavenProjectChangedListener, IResource
       log.error(e.getMessage(), e);
     }
   }
+
+  static class ModuleInfoDetector implements IResourceDeltaVisitor {
+
+    private Collection<IProject> affectedProjects;
+
+    public ModuleInfoDetector(Collection<IProject> affectedProjects) {
+      this.affectedProjects = affectedProjects;
+    }
+
+    public boolean visit(IResourceDelta delta) {
+      if(delta.getResource() instanceof IFile) {
+        IFile file = (IFile) delta.getResource();
+        if(ModuleSupport.MODULE_INFO_JAVA.equals(file.getName())) {
+          affectedProjects.add(file.getProject());
+        }
+        return false;
+      }
+      return true;
+    }
+
+  }
 }
diff --git a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/InternalModuleSupport.java b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/InternalModuleSupport.java
index c0da59c1..1e4f9310 100644
--- a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/InternalModuleSupport.java
+++ b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/InternalModuleSupport.java
@@ -110,7 +110,7 @@ class InternalModuleSupport {
       if(monitor.isCanceled()) {
         return;
       }
-      String moduleName = getModuleName(entry, monitor);
+      String moduleName = getModuleName(entry.getEntryKind(), entry.getPath(), monitor);
       moduleMap.put(moduleName, entry);//potentially suppresses duplicate entries from the same workspace project, with different classifiers
       descriptorsMap.put(entry, moduleName);
     }
@@ -163,12 +163,12 @@ class InternalModuleSupport {
     return Collections.emptySet();
   }
 
-  private static Set<String> getRequiredModules(IJavaProject project, IProgressMonitor monitor)
+  public static Set<String> getRequiredModules(IJavaProject project, IProgressMonitor monitor)
       throws JavaModelException {
     IModuleDescription moduleDescription = project.getModuleDescription();
     if(moduleDescription != null) {
       String[] reqModules = JavaModelAccess.getRequiredModules(moduleDescription);
-      return new LinkedHashSet<>(Arrays.asList(reqModules));
+      return Collections.unmodifiableSet(new LinkedHashSet<>(Arrays.asList(reqModules)));
     }
     return Collections.emptySet();
   }
@@ -196,13 +196,13 @@ class InternalModuleSupport {
     return Collections.emptySet();
   }
 
-  private static String getModuleName(IClasspathEntryDescriptor entry, IProgressMonitor monitor) {
+  public static String getModuleName(int entryKind, IPath entryPath, IProgressMonitor monitor) {
     String module = null;
-    if(entry != null) {
-      if(IClasspathEntry.CPE_LIBRARY == entry.getEntryKind()) {
-        module = getModuleName(entry.getPath().toFile());
-      } else if(IClasspathEntry.CPE_PROJECT == entry.getEntryKind()) {
-        module = getModuleName(getJavaProject(entry.getPath()), monitor);
+    if(entryPath != null) {
+      if(IClasspathEntry.CPE_LIBRARY == entryKind) {
+        module = getModuleName(entryPath.toFile());
+      } else if(IClasspathEntry.CPE_PROJECT == entryKind) {
+        module = getModuleName(getJavaProject(entryPath), monitor);
       }
     }
     return module;
@@ -271,11 +271,13 @@ class InternalModuleSupport {
     return new String(moduleName);
   }
 
-  public static int determineModularClasspathProperty(IClasspathEntry entry) {
+  public static boolean isModuleEntry(IClasspathEntry entry) {
     return Arrays.stream(entry.getExtraAttributes())
-        .anyMatch(p -> p.getName().equals(IClasspathAttribute.MODULE) && "true".equals(p.getValue()))
-            ? IRuntimeClasspathEntry.MODULE_PATH
-            : IRuntimeClasspathEntry.CLASS_PATH;
+        .anyMatch(p -> IClasspathAttribute.MODULE.equals(p.getName()) && "true".equals(p.getValue()));
+  }
+
+  public static int determineModularClasspathProperty(IClasspathEntry entry) {
+    return isModuleEntry(entry) ? IRuntimeClasspathEntry.MODULE_PATH : IRuntimeClasspathEntry.CLASS_PATH;
   }
 
   public static IRuntimeClasspathEntry createRuntimeClasspathEntry(IFolder folder, int classpathProperty,
diff --git a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/Messages.java b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/Messages.java
index 21e89cf9..be0c754e 100644
--- a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/Messages.java
+++ b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/Messages.java
@@ -26,6 +26,8 @@ public class Messages extends NLS {
 
   public static String BuildPathManager_monitor_setting_cp;
 
+  public static String BuildPathManager_update_module_path_job_name;
+
   public static String DownloadSourcesJob_job_download;
 
   public static String MavenClasspathContainer_description;
diff --git a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/ModuleSupport.java b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/ModuleSupport.java
index 33672823..387a4af7 100644
--- a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/ModuleSupport.java
+++ b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/ModuleSupport.java
@@ -11,6 +11,11 @@
 
 package org.eclipse.m2e.jdt.internal;
 
+import java.util.Set;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import org.eclipse.core.resources.IFolder;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.runtime.CoreException;
@@ -18,9 +23,12 @@ import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.debug.core.ILaunchConfiguration;
 import org.eclipse.jdt.core.IClasspathEntry;
 import org.eclipse.jdt.core.IJavaProject;
+import org.eclipse.jdt.core.JavaCore;
+import org.eclipse.jdt.core.JavaModelException;
 import org.eclipse.jdt.launching.IRuntimeClasspathEntry;
 import org.eclipse.jdt.launching.JavaRuntime;
 
+import org.eclipse.m2e.core.internal.IMavenConstants;
 import org.eclipse.m2e.core.project.IMavenProjectFacade;
 import org.eclipse.m2e.jdt.IClasspathDescriptor;
 
@@ -33,10 +41,14 @@ import org.eclipse.m2e.jdt.IClasspathDescriptor;
  */
 public class ModuleSupport {
 
+  public static final String MODULE_INFO_JAVA = "module-info.java";
+
   static final boolean IS_MODULE_SUPPORT_AVAILABLE;
 
   static final boolean IS_PATCH_MODULE_SUPPORT_AVAILABLE;
 
+  private static final Logger log = LoggerFactory.getLogger(ModuleSupport.class);
+
   static {
     boolean isModuleSupportAvailable = false;
     boolean isPatchModuleSupportAvailable = false;
@@ -64,7 +76,7 @@ public class ModuleSupport {
    */
   public static void configureClasspath(IMavenProjectFacade facade, IClasspathDescriptor classpath,
       IProgressMonitor monitor) throws CoreException {
-    if(!IS_MODULE_SUPPORT_AVAILABLE) {
+    if(!IS_MODULE_SUPPORT_AVAILABLE || classpath == null) {
       return;
     }
     InternalModuleSupport.configureClasspath(facade, classpath, monitor);
@@ -105,4 +117,18 @@ public class ModuleSupport {
     }
     return InternalModuleSupport.newModularProjectRuntimeClasspathEntry(javaProject);
   }
+
+  public static boolean isMavenJavaProject(IProject project) {
+    try {
+      return project != null && project.isOpen() && project.hasNature(IMavenConstants.NATURE_ID)
+          && project.hasNature(JavaCore.NATURE_ID);
+    } catch(CoreException ex) {
+      log.error(ex.getMessage(), ex);
+    }
+    return false;
+  }
+
+  public static Set<String> getRequiredModules(IJavaProject jp, IProgressMonitor monitor) throws JavaModelException {
+    return InternalModuleSupport.getRequiredModules(jp, monitor);
+  }
 }
diff --git a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/messages.properties b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/messages.properties
index 676bcaf6..c058c84a 100644
--- a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/messages.properties
+++ b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/messages.properties
@@ -1,5 +1,6 @@
 AbstractJavaProjectConfigurator_task_name=Configuring java project 
 BuildPathManager_monitor_setting_cp=Setting classpath containers
+BuildPathManager_update_module_path_job_name=Updating module path
 DownloadSourcesJob_job_download=Download sources and javadoc
 MavenClasspathContainer_description=Maven Dependencies
 MavenClasspathContainerInitializer_error_cannot_persist=Can't persist classpath container