diff --git a/src/main/java/hello/controller/HelloController.java b/src/main/java/hello/controller/HelloController.java
index f3602fa..0c30e60 100644
--- a/src/main/java/hello/controller/HelloController.java
+++ b/src/main/java/hello/controller/HelloController.java
@@ -29,10 +29,6 @@ public class HelloController {
             "Select ID With \"Java\" Keyword," +
             " Then Sort Then Join ";
     String findIdHavingCharacterTemplate = "-------------Return All ID having character \'g\' in it:  ";
-    String findAllFilesInPathAndSortTemplate = "---------Find all files in path and sort:    ";
-    String findParticularFileInPathAndSortTemplate = "----------Find File in present directory which strats with \"grad\",provided maximum depth=25 and sort : ";
-    String findParticularFileInPathAndSortWithWalkFunctionTemplate = "----------Find File in present directory which strats with \"grad\",provided maximum depth=25 and sort :  with walk function";
-    String readFileWithStreamFunctionTemplate = "---------Read \"temp.txt\" file with stream functions, having \"print\" witin it:  ";
 
 
     @Autowired
@@ -80,22 +76,4 @@ public String showStringOperation() {
     }
 
 
-    /**
-     * File Operation in Java 8
-     * @return
-     */
-    @RequestMapping("/topic/file/operation")
-    public String showFileOperation() {
-        String findAllFilesInPathAndSort = topicService.findAllFilesInPathAndSort();
-        String findParticularFileInPathAndSort = topicService.findParticularFileInPathAndSort();
-        String findParticularFileInPathAndSortWithWalkFunction = topicService.findParticularFileInPathAndSortWithWalkFunction();
-        String readFileWithStreamFunction = topicService.readFileWithStreamFunction();
-        return findAllFilesInPathAndSortTemplate + findAllFilesInPathAndSort
-                + findParticularFileInPathAndSortTemplate + findParticularFileInPathAndSort
-                + findParticularFileInPathAndSortWithWalkFunctionTemplate + findParticularFileInPathAndSortWithWalkFunction
-                + readFileWithStreamFunctionTemplate + readFileWithStreamFunction;
-    }
-
-
-
 }
diff --git a/src/main/java/hello/service/TopicService.java b/src/main/java/hello/service/TopicService.java
index feffb92..c447a13 100644
--- a/src/main/java/hello/service/TopicService.java
+++ b/src/main/java/hello/service/TopicService.java
@@ -4,11 +4,6 @@
 import hello.model.Topic;
 import org.springframework.stereotype.Service;
 
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.*;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
@@ -157,84 +152,4 @@ public String findIdHavingCharacter() {
                 .toString();
     }
 
-
-    /**
-     * NIO Java API
-     * Use Streams with files
-     * Try with resource, "Autoclose"
-     *
-     * @return
-     */
-    public String findAllFilesInPathAndSort() {
-        try (Stream<Path> stream = Files.list(Paths.get(""))) {
-            String joined = stream
-                    .map(String::valueOf)
-                    .filter(path -> !path.startsWith("."))
-                    .sorted()
-                    .collect(Collectors.joining("; "));
-            return joined;
-        } catch (IOException e) {
-            return " Error in IO";
-        }
-    }
-
-    /**
-     * Using File.find function to find file
-     * @return
-     */
-    public String findParticularFileInPathAndSort() {
-        Path start = Paths.get("");
-        int maxDepth = 25;
-        try (Stream<Path> stream = Files.find(start, maxDepth, (path, attr) ->
-                String.valueOf(path).startsWith("grad"))) {
-            String joined = stream
-                    .sorted()
-                    .map(String::valueOf)
-                    .collect(Collectors.joining("; "));
-            return joined;
-        } catch (IOException e) {
-            return " IO exception ";
-        }
-    }
-
-
-    /**
-     * Using Files.Walk Function to find File
-     * @return
-     */
-    public String findParticularFileInPathAndSortWithWalkFunction() {
-        Path start = Paths.get("");
-        int maxDepth = 5;
-        try (Stream<Path> stream = Files.walk(start, maxDepth)) {
-            String joined = stream
-                    .map(String::valueOf)
-                    .filter(path -> path.startsWith("grad"))
-                    .sorted()
-                    .collect(Collectors.joining("; "));
-            return joined;
-        } catch (IOException e) {
-            return " IO exception ";
-        }
-    }
-
-
-    /**
-     * Use BufferedReader with Stream functions
-     * @return
-     */
-    public String readFileWithStreamFunction() {
-        Path path = Paths.get("temp.txt");
-        System.out.println();
-        try (BufferedReader reader = Files.newBufferedReader(path)) {
-            String lines = reader
-                    .lines()
-                    .filter(line->line.contains("print"))
-                    .map(line->line.substring("print".length()))
-                    .collect(Collectors.joining(","));
-            return  lines;
-        } catch (IOException e) {
-            return " IO exception ";
-        }
-    }
-
 }