Add list files in directory snippet

iluwatar · iluwatar · commit e3d03e0ea411 · 2017-12-20T21:39:38.000+02:00
diff --git a/README.md b/README.md
@@ -15,6 +15,7 @@ Update the sample application with the snippet and add a test for it. After prov
 
 ### File
 * [List directories](#list-directories)
+* [List files in directory](#list-files-in-directory)
 * [Read lines from file to string list](#read-lines-from-file-to-string-list)
 
 ### Math
@@ -75,6 +76,16 @@ Update the sample application with the snippet and add a test for it. After prov
 
 [⬆ back to top](#table-of-contents)
 
+### List files in directory
+
+```java
+    public static File[] listFilesInDirectory(final File folder) {
+        return folder.listFiles(File::isFile);
+    }
+```
+
+[⬆ back to top](#table-of-contents)
+
 ### Read lines from file to string list
 
 ```java
diff --git a/src/main/java/Library.java b/src/main/java/Library.java
@@ -6,6 +6,7 @@
 import java.nio.file.Files;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
@@ -149,4 +150,13 @@ public static boolean isPalindrome(String s) {
         String backward = sb.reverse().toString().toLowerCase();
         return forward.equals(backward);
     }
+
+    /**
+     * List files in directory
+     * @param folder the path where to look
+     * @return array of File
+     */
+    public static File[] listFilesInDirectory(final File folder) {
+        return folder.listFiles(File::isFile);
+    }
 }
diff --git a/src/test/java/LibraryTest.java b/src/test/java/LibraryTest.java
@@ -162,4 +162,14 @@ public void testIsPalindrome() {
         assertFalse(Library.isPalindrome("Type O Negative"));
         assertFalse(Library.isPalindrome("Foo12121Bar"));
     }
+
+    /**
+     * Tests for {@link Library#listFilesInDirectory(File)}
+     */
+    @Test
+    public void testListFilesInDirectory() {
+        File[] files = Library.listFilesInDirectory(new File("src/test/resources"));
+        assertEquals(1, files.length);
+        assertEquals("src/test/resources/somelines.txt", files[0].toString());
+    }
 }
