eugenp · saajn · Jun 30, 2024 · Jun 17, 2024 · Jun 17, 2024 · Jun 17, 2024
diff --git a/core-java-modules/core-java-io-6/pom.xml b/core-java-modules/core-java-io-6/pom.xml
@@ -17,7 +17,28 @@
 
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${java.version}</source>
+                    <target>${java.version}</target>
+                    <annotationProcessorPaths>
+                        <path>
+                            <groupId>org.openjdk.jmh</groupId>
+                            <artifactId>jmh-generator-annprocess</artifactId>
+                            <version>${jmh-generator.version}</version>
+                        </path>
+                    </annotationProcessorPaths>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
     <properties>
 
     </properties>
-</project>
+</project>
diff --git a/...ore-java-io-6/src/main/java/com/baeldung/filewritervsbufferedwriter/BenchmarkWriters.java b/...ore-java-io-6/src/main/java/com/baeldung/filewritervsbufferedwriter/BenchmarkWriters.java
@@ -0,0 +1,160 @@
+package com.baeldung.filewritervsbufferedwriter;
+
+import org.openjdk.jmh.annotations.*;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.concurrent.TimeUnit;
+
+@State(Scope.Benchmark)
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+@Warmup(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS)
+@Measurement(iterations = 10, time = 10, timeUnit = TimeUnit.SECONDS)
+@Fork(1)
+public class BenchmarkWriters {
+
+    private static final Logger log = LoggerFactory.getLogger(BenchmarkWriters.class);
+    private static final String FILE_PATH = "benchmark.txt";
+    private static final String CONTENT = "This is a test line.";
+    private static final int BUFSIZE = 4194304; // 4MiB
+
+    @Benchmark
+    public void fileWriter1Write() {
+        try (FileWriter writer = new FileWriter(FILE_PATH, true)) {
+            writer.write(CONTENT);
+            writer.close();
+        } catch (IOException e) {
+            log.error("Error in FileWriter 1 write", e);
+        }
+    }
+
+    @Benchmark
+    public void bufferedWriter1Write() {
+        try (BufferedWriter writer = new BufferedWriter(new FileWriter(FILE_PATH, true), BUFSIZE)) {
+            writer.write(CONTENT);
+            writer.close();
+        } catch (IOException e) {
+            log.error("Error in BufferedWriter 1 write", e);
+        }
+    }
+
+    @Benchmark
+    public void fileWriter10Writes() {
+        try (FileWriter writer = new FileWriter(FILE_PATH, true)) {
+            for (int i = 0; i < 10; i++) {
+                writer.write(CONTENT);
+            }
+            writer.close();
+        } catch (IOException e) {
+            log.error("Error in FileWriter 10 writes", e);
+        }
+    }
+
+    @Benchmark
+    public void bufferedWriter10Writes() {
+        try (BufferedWriter writer = new BufferedWriter(new FileWriter(FILE_PATH, true), BUFSIZE)) {
+            for (int i = 0; i < 10; i++) {
+                writer.write(CONTENT);
+            }
+            writer.close();
+        } catch (IOException e) {
+            log.error("Error in BufferedWriter 10 writes", e);
+        }
+    }
+
+    @Benchmark
+    public void fileWriter1000Writes() {
+        try (FileWriter writer = new FileWriter(FILE_PATH, true)) {
+            for (int i = 0; i < 1000; i++) {
+                writer.write(CONTENT);
+            }
+            writer.close();
+        } catch (IOException e) {
+            log.error("Error in FileWriter 1000 writes", e);
+        }
+    }
+
+    @Benchmark
+    public void bufferedWriter1000Writes() {
+        try (BufferedWriter writer = new BufferedWriter(new FileWriter(FILE_PATH, true), BUFSIZE)) {
+            for (int i = 0; i < 1000; i++) {
+                writer.write(CONTENT);
+            }
+            writer.close();
+        } catch (IOException e) {
+            log.error("Error in BufferedWriter 1000 writes", e);
+        }
+    }
+
+    @Benchmark
+    public void fileWriter10000Writes() {
+        try (FileWriter writer = new FileWriter(FILE_PATH, true)) {
+            for (int i = 0; i < 10000; i++) {
+                writer.write(CONTENT);
+            }
+            writer.close();
+        } catch (IOException e) {
+            log.error("Error in FileWriter 10000 writes", e);
+        }
+    }
+
+    @Benchmark
+    public void bufferedWriter10000Writes() {
+        try (BufferedWriter writer = new BufferedWriter(new FileWriter(FILE_PATH, true), BUFSIZE)) {
+            for (int i = 0; i < 10000; i++) {
+                writer.write(CONTENT);
+            }
+            writer.close();
+        } catch (IOException e) {
+            log.error("Error in BufferedWriter 10000 writes", e);
+        }
+    }
+
+    @Benchmark
+    public void fileWriter100000Writes() {
+        try (FileWriter writer = new FileWriter(FILE_PATH, true)) {
+            for (int i = 0; i < 100000; i++) {
+                writer.write(CONTENT);
+            }
+            writer.close();
+        } catch (IOException e) {
+            log.error("Error in FileWriter 100000 writes", e);
+        }
+    }
+
+    @Benchmark
+    public void bufferedWriter100000Writes() {
+        try (BufferedWriter writer = new BufferedWriter(new FileWriter(FILE_PATH, true), BUFSIZE)) {
+            for (int i = 0; i < 100000; i++) {
+                writer.write(CONTENT);
+            }
+            writer.close();
+        } catch (IOException e) {
+            log.error("Error in BufferedWriter 100000 writes", e);
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+        Files.deleteIfExists(Paths.get(FILE_PATH));
+
+        // We need to extract the classpath from the class loader before calling JMH
+        // This is necessary to load org.openjdk.jmh.runner.ForkedMain
+        URLClassLoader classLoader = (URLClassLoader) BenchmarkWriters.class.getClassLoader();
+        StringBuilder classpath = new StringBuilder();
+        for (URL url : classLoader.getURLs()) {
+            classpath.append(url.getPath()).append(File.pathSeparator);
+        }
+        System.setProperty("java.class.path", classpath.toString());
+
+        org.openjdk.jmh.Main.main(args);
+    }
+}
diff --git a/...va-io-6/src/test/java/com/baeldung/filewritervsbufferedwriter/BufferedWriterUnitTest.java b/...va-io-6/src/test/java/com/baeldung/filewritervsbufferedwriter/BufferedWriterUnitTest.java
@@ -0,0 +1,60 @@
+package com.baeldung.filewritervsbufferedwriter;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class BufferedWriterUnitTest {
+
+    private static final String FILE_PATH = "testBufferedFile.txt";
+
+    @BeforeEach
+    void setUp() throws IOException {
+        Files.deleteIfExists(Paths.get(FILE_PATH));
+    }
+
+    @AfterEach
+    void tearDown() throws IOException {
+        Files.deleteIfExists(Paths.get(FILE_PATH));
+    }
+
+    @Test
+    void whenWritingUsingBufferedWriter_thenContentIsCorrect() throws IOException {
+        String content = "Hello, Buffered Baeldung!";
+        BufferedWriter writer = new BufferedWriter(new FileWriter(FILE_PATH));
+        writer.write(content);
+        writer.close();
+
+        StringBuilder fileContent = new StringBuilder();
+        FileReader reader = new FileReader(FILE_PATH);
+        try {
+            int ch;
+            while ((ch = reader.read()) != -1) {
+                fileContent.append((char) ch);
+            }
+        } finally {
+            reader.close();
+        }
+
+        assertEquals(content, fileContent.toString());
+    }
+
+    @Test
+    void whenBufferedFileIsWritten_thenFileExists() throws IOException {
+        BufferedWriter writer = new BufferedWriter(new FileWriter(FILE_PATH));
+        writer.write("Sample buffered content");
+        writer.close();
+
+        File file = new File(FILE_PATH);
+        assertTrue(file.exists());
+    }
+}
diff --git a/...e-java-io-6/src/test/java/com/baeldung/filewritervsbufferedwriter/FileWriterUnitTest.java b/...e-java-io-6/src/test/java/com/baeldung/filewritervsbufferedwriter/FileWriterUnitTest.java
@@ -0,0 +1,59 @@
+package com.baeldung.filewritervsbufferedwriter;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.io.File;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class FileWriterUnitTest {
+
+    private static final String FILE_PATH = "testFile.txt";
+
+    @BeforeEach
+    void setUp() throws IOException {
+        Files.deleteIfExists(Paths.get(FILE_PATH));
+    }
+
+    @AfterEach
+    void tearDown() throws IOException {
+        Files.deleteIfExists(Paths.get(FILE_PATH));
+    }
+
+    @Test
+    void whenWritingToFile_thenContentIsCorrect() throws IOException {
+        String content = "Hello, Baeldung!";
+        FileWriter writer = new FileWriter(FILE_PATH);
+        writer.write(content);
+        writer.close();
+
+        StringBuilder fileContent = new StringBuilder();
+        FileReader reader = new FileReader(FILE_PATH);
+        try {
+            int ch;
+            while ((ch = reader.read()) != -1) {
+                fileContent.append((char) ch);
+            }
+        } finally {
+            reader.close();
+        }
+
+        assertEquals(content, fileContent.toString());
+    }
+
+    @Test
+    void whenFileIsWritten_thenFileExists() throws IOException {
+        FileWriter writer = new FileWriter(FILE_PATH);
+        writer.write("Sample content");
+        writer.close();
+
+        File file = new File(FILE_PATH);
+        assertTrue(file.exists());
+    }
+}