Minor improvements in tool tasks

- Use java 8 types in UpdateDocsTask
- Simplify permissions page writing task to write to the file without any options
- Various minor simplifications (Java 8) to avoid casting etc.

src/test/java/tools/docs/UpdateDocsTask.java

@@ -9,14 +9,15 @@ import tools.utils.ToolTask;
 
 import java.util.Scanner;
 import java.util.Set;
+import java.util.function.Consumer;
 
 /**
  * Task that runs all tasks which update files in the docs folder.
  */
 public class UpdateDocsTask implements AutoToolTask {
 
-    private static final Set<Class<? extends ToolTask>> TASKS = ImmutableSet.<Class<? extends ToolTask>>of(
-        CommandPageCreater.class, HashAlgorithmsDescriptionTask.class, PermissionsListWriter.class);
+    private static final Set<Class<? extends ToolTask>> TASKS = ImmutableSet
+        .of(CommandPageCreater.class, HashAlgorithmsDescriptionTask.class, PermissionsListWriter.class);
 
     @Override
     public String getTaskName() {
@@ -25,22 +26,14 @@ public class UpdateDocsTask implements AutoToolTask {
 
     @Override
     public void execute(final Scanner scanner) {
-        executeTasks(new TaskRunner() {
-            @Override
-            public void execute(ToolTask task) {
-                task.execute(scanner);
-            }
-        });
+        executeTasks(task -> task.execute(scanner));
     }
 
     @Override
     public void executeDefault() {
-        executeTasks(new TaskRunner() {
-            @Override
-            public void execute(ToolTask task) {
-                if (task instanceof AutoToolTask) {
-                    ((AutoToolTask) task).executeDefault();
-                }
+        executeTasks(task -> {
+            if (task instanceof AutoToolTask) {
+                ((AutoToolTask) task).executeDefault();
             }
         });
     }
@@ -49,24 +42,15 @@ public class UpdateDocsTask implements AutoToolTask {
         try {
             return clazz.newInstance();
         } catch (IllegalAccessException | InstantiationException e) {
-            throw new UnsupportedOperationException(e);
+            throw new UnsupportedOperationException("Could not instantiate task class '" + clazz + "'", e);
         }
     }
 
-    private static void executeTasks(TaskRunner runner) {
+    private static void executeTasks(Consumer<ToolTask> taskRunner) {
         for (Class<? extends ToolTask> taskClass : TASKS) {
-            try {
-                ToolTask task = instantiateTask(taskClass);
-                System.out.println("\nRunning " + task.getTaskName() + "\n-------------------");
-                runner.execute(task);
-            } catch (UnsupportedOperationException e) {
-                System.err.println("Error running task of class '" + taskClass + "'");
-                e.printStackTrace();
-            }
+            ToolTask task = instantiateTask(taskClass);
+            System.out.println("\nRunning " + task.getTaskName() + "\n-------------------");
+            taskRunner.accept(task);
         }
     }
-
-    private interface TaskRunner {
-        void execute(ToolTask task);
-    }
 }