BAEL-6545: Update article https://www.baeldung.com/java-read-lines-large-file (#14168)

core-java-modules/core-java-io-2/src/test/java/com/baeldung/readlargefile/ReadLargeFileUnitTest.java

@@ -1,9 +1,16 @@
 package com.baeldung.readlargefile;
 
+import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.FileReader;
 import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.SeekableByteChannel;
+import java.nio.file.Paths;
+import java.nio.file.StandardOpenOption;
 import java.util.Scanner;
+import java.util.stream.Stream;
 
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.LineIterator;
@@ -93,6 +100,61 @@ public class ReadLargeFileUnitTest {
         logMemory();
     }
 
+    @Test
+    public void givenUsingBufferedReader_whenIteratingAFile_thenCorrect() throws IOException {
+        String fileName = "src/test/resources/myFile";
+
+        logMemory();
+        try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
+            while (br.readLine() != null) {
+                // do something with each line
+            }
+        }
+        logMemory();
+    }
+
+    @Test
+    public void givenUsingNewBufferedReader_whenIteratingAFile_thenCorrect() throws IOException {
+        String fileName = "src/test/resources/myFile";
+
+        logMemory();
+        try (BufferedReader br = java.nio.file.Files.newBufferedReader(Paths.get(fileName))) {
+            while (br.readLine() != null) {
+                // do something with each line
+            }
+        }
+        logMemory();
+    }
+
+    @Test
+    public void givenUsingSeekableByteChannel_whenIteratingAFile_thenCorrect() throws IOException {
+        String fileName = "src/test/resources/myFile";
+
+        logMemory();
+        try (SeekableByteChannel ch = java.nio.file.Files.newByteChannel(Paths.get(fileName), StandardOpenOption.READ)) {
+            ByteBuffer bf = ByteBuffer.allocate(1000);
+            while (ch.read(bf) > 0) {
+                bf.flip();
+                // System.out.println(new String(bf.array()));
+                bf.clear();
+            }
+        }
+        logMemory();
+    }
+
+    @Test
+    public void givenUsingStreamApi_whenIteratingAFile_thenCorrect() throws IOException {
+        String fileName = "src/test/resources/myFile";
+
+        logMemory();
+        try (Stream<String> lines = java.nio.file.Files.lines(Paths.get(fileName))) {
+            lines.forEach(line -> {
+                // do something with each line
+            });
+        }
+        logMemory();
+    }
+
     // utils
 
     private final void logMemory() {