fix Sonar issues in PluginFramework (#3845)

* synchronize setPluginDirectory(String directory)

* limit visibility of PluginFramework constructor

* no need for protected in final class

* fix doc

Author: Vladimir Kotal

opengrok-indexer/src/main/java/org/opengrok/indexer/authorization/AuthorizationFramework.java

@@ -245,7 +245,7 @@ public void setStack(AuthorizationStack s) {
      * @param stack  the stack
      * @param entity the authorization entity (stack or plugin)
      */
-    protected void addPlugin(AuthorizationStack stack, AuthorizationEntity entity) {
+    void addPlugin(AuthorizationStack stack, AuthorizationEntity entity) {
         if (stack != null) {
             stack.add(entity);
         }
@@ -378,12 +378,12 @@ protected void afterReload() {
         loadAllPlugins(loadingStack);
 
         AuthorizationStack oldStack;
-        /**
-         * Replace the stack in a write lock to avoid inconsistent state between
+        /*
+         * Replace the stack in write lock to avoid inconsistent state between
          * the stack change and currently executing requests performing some
          * authorization on the same stack.
          *
-         * @see #performCheck is controlled with a read lock
+         * performCheck() uses read lock.
          */
         lock.writeLock().lock();
         try {

opengrok-indexer/src/main/java/org/opengrok/indexer/framework/PluginFramework.java

@@ -80,7 +80,7 @@ public abstract class PluginFramework<PluginType> {
      * @param classType the class of the plugin type
      * @param path      the plugin directory path
      */
-    public PluginFramework(Class<PluginType> classType, String path) {
+    protected PluginFramework(Class<PluginType> classType, String path) {
         this.classType = classType;
         setPluginDirectory(path);
     }
@@ -108,7 +108,7 @@ public synchronized void setPluginDirectory(File pluginDirectory) {
      *
      * @param directory the directory path
      */
-    public void setPluginDirectory(String directory) {
+    public synchronized void setPluginDirectory(String directory) {
         setPluginDirectory(directory != null ? new File(directory) : null);
     }
 

opengrok-indexer/src/test/java/org/opengrok/indexer/authorization/AuthorizationFrameworkTest.java

@@ -32,6 +32,7 @@
 import java.util.stream.Collectors;
 
 import jakarta.servlet.http.HttpServletRequest;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
 import org.opengrok.indexer.condition.DeliberateRuntimeException;
@@ -929,4 +930,15 @@ private static TestCase NewTest(boolean expected, Nameable entity) {
     private static TestCase NewTest(boolean expected, HttpServletRequest request, Nameable entity) {
         return new TestCase(expected, request, entity);
     }
+
+    @Test
+    void setPluginDirectoryTest() {
+        String pluginDirectoryPath = "foo";
+        AuthorizationFramework authorizationFramework = new AuthorizationFramework(pluginDirectoryPath, null);
+        assertEquals(pluginDirectoryPath, authorizationFramework.getPluginDirectory().toString());
+
+        pluginDirectoryPath = "bar";
+        authorizationFramework.setPluginDirectory(pluginDirectoryPath);
+        assertEquals(pluginDirectoryPath, authorizationFramework.getPluginDirectory().toString());
+    }
 }