Added the code for "The difference between BufferedReader and FileReader". (#13942)

core-java-modules/core-java-io-apis-2/src/test/java/com/baeldung/bufferedreadervsfilereader/BufferedReaderUnitTest.java

@@ -0,0 +1,31 @@
+package com.baeldung.bufferedreadervsfilereader;
+
+import org.junit.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+
+public class BufferedReaderUnitTest {
+
+    @Test
+    public void whenReadingAFile_thenReadsLineByLine() {
+        StringBuilder result = new StringBuilder();
+
+        try (BufferedReader br = new BufferedReader(new FileReader("src/test/resources/sampleText1.txt"))) {
+            String line;
+
+            while((line = br.readLine()) != null) {
+                result.append(line);
+                result.append('\n');
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        assertEquals("first line\nsecond line\nthird line\n", result.toString());
+    }
+
+}

core-java-modules/core-java-io-apis-2/src/test/java/com/baeldung/bufferedreadervsfilereader/FileReaderUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.bufferedreadervsfilereader;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.FileReader;
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class FileReaderUnitTest {
+
+    @Test
+    public void whenReadingAFile_thenReadsCharByChar() {
+        StringBuilder result = new StringBuilder();
+
+        try (FileReader fr = new FileReader("src/test/resources/sampleText2.txt")) {
+            int i = fr.read();
+
+            while(i != -1) {
+                result.append((char)i);
+
+                i = fr.read();
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        assertEquals("qwerty", result.toString());
+    }
+}

core-java-modules/core-java-io-apis-2/src/test/resources/sampleText1.txt

@@ -0,0 +1,3 @@
+first line
+second line
+third line

core-java-modules/core-java-io-apis-2/src/test/resources/sampleText2.txt

@@ -0,0 +1 @@
+qwerty