Avoid to call search engine to get project when only one project in workspace (#236)

Signed-off-by: Jinbo Wang <[email protected]>

Author: testforstephen

com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/JdtUtils.java

@@ -17,6 +17,7 @@
 import java.util.List;
 import java.util.Set;
 
+import org.apache.commons.lang3.StringUtils;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.IWorkspaceRoot;
@@ -103,20 +104,33 @@ public static IJavaProject getJavaProject(IProject project) {
      * If the project doesn't exist or not a java project, return null.
      */
     public static IJavaProject getJavaProject(String projectName) {
-        if (projectName == null) {
+        if (StringUtils.isBlank(projectName)) {
             return null;
         }
         IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
         IProject project = root.getProject(projectName);
         return getJavaProject(project);
     }
 
+    /**
+     * List all available Java projects of the specified workspace.
+     */
+    public static List<IJavaProject> listJavaProjects(IWorkspaceRoot workspace) {
+        List<IJavaProject> results = new ArrayList<>();
+        for (IProject project : workspace.getProjects()) {
+            if (isJavaProject(project)) {
+                results.add(JavaCore.create(project));
+            }
+        }
+        return results;
+    }
+
     /**
      * Given the project name, return the corresponding project object.
      * If the project doesn't exist, return null.
      */
     public static IProject getProject(String projectName) {
-        if (projectName == null) {
+        if (StringUtils.isBlank(projectName)) {
             return null;
         }
         IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();

com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/ResolveClasspathsHandler.java

@@ -19,6 +19,8 @@
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
 
+import org.apache.commons.lang3.StringUtils;
+import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
@@ -83,6 +85,12 @@ private static IJavaProject getJavaProjectFromName(String projectName) throws Co
      *             CoreException
      */
     public static List<IJavaProject> getJavaProjectFromType(String fullyQualifiedTypeName) throws CoreException {
+        // If only one Java project exists in the whole workspace, return the project directly.
+        List<IJavaProject> javaProjects = JdtUtils.listJavaProjects(ResourcesPlugin.getWorkspace().getRoot());
+        if (javaProjects.size() <= 1) {
+            return javaProjects;
+        }
+
         String[] splitItems = fullyQualifiedTypeName.split("/");
         // If the main class name contains the module name, should trim the module info.
         if (splitItems.length == 2) {
@@ -132,7 +140,7 @@ private static String[][] computeClassPath(String mainClass, String projectName)
         IJavaProject project = null;
         // if type exists in multiple projects, debug configuration need provide
         // project name.
-        if (projectName != null) {
+        if (StringUtils.isNotBlank(projectName)) {
             project = getJavaProjectFromName(projectName);
         } else {
             List<IJavaProject> projects = getJavaProjectFromType(mainClass);