BAEL-7490 read write file in separate thread (#15664)

* BAEL-7490 read write file in separate thread

* Change the to try resources

* Update the code to sync with article

core-java-modules/core-java-io-5/file.txt

@@ -0,0 +1 @@
+Hello, world!

core-java-modules/core-java-io-5/src/main/java/com/baeldung/readwritethread/ReadWriteBlockingQueue.java

@@ -0,0 +1,85 @@
+package com.baeldung.readwritethread;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+
+public class ReadWriteBlockingQueue {
+
+    public static void main(String[] args) throws InterruptedException {
+
+        BlockingQueue<String> queue = new LinkedBlockingQueue<>();
+        String readFileName = "src/main/resources/read_file.txt";
+        String writeFileName = "src/main/resources/write_file.txt";
+
+        Thread producerThread = new Thread(new FileProducer(queue, readFileName));
+        Thread consumerThread1 = new Thread(new FileConsumer(queue, writeFileName));
+
+        producerThread.start();
+        Thread.sleep(100); // Give producer a head start
+        consumerThread1.start();
+        try {
+            producerThread.join();
+            consumerThread1.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+
+    }
+}
+
+class FileProducer implements Runnable {
+
+    private final BlockingQueue<String> queue;
+    private final String inputFileName;
+
+    public FileProducer(BlockingQueue<String> queue, String inputFileName) {
+        this.queue = queue;
+        this.inputFileName = inputFileName;
+    }
+
+    @Override
+    public void run() {
+        try (BufferedReader reader = new BufferedReader(new FileReader(inputFileName))) {
+            String line;
+            while ((line = reader.readLine()) != null) {
+                queue.offer(line);
+                System.out.println("Producer added line: " + line);
+                System.out.println("Queue size: " + queue.size());
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}
+
+class FileConsumer implements Runnable {
+
+    private final BlockingQueue<String> queue;
+    private final String outputFileName;
+
+    public FileConsumer(BlockingQueue queue, String outputFileName) {
+        this.queue = queue;
+        this.outputFileName = outputFileName;
+    }
+
+    @Override
+    public void run() {
+        try (BufferedWriter writer = new BufferedWriter(new FileWriter(outputFileName))) {
+            String line;
+            while ((line = queue.poll()) != null) {
+                writer.write(line);
+                writer.newLine();
+                System.out.println(Thread.currentThread()
+                    .getId() + " - Consumer processed line: " + line);
+                System.out.println("Queue size: " + queue.size());
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}

core-java-modules/core-java-io-5/src/main/java/com/baeldung/readwritethread/ReadWriteThread.java

@@ -0,0 +1,55 @@
+package com.baeldung.readwritethread;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+
+public class ReadWriteThread {
+
+    public static void readFile(String filePath) {
+        Thread thread = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                try (BufferedReader bufferedReader = new BufferedReader(new FileReader(filePath))) {
+                    String line;
+                    while ((line = bufferedReader.readLine()) != null) {
+                        System.out.println(line);
+                    }
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        });
+        thread.start();
+    }
+
+    public static void writeFile(String filePath, String content) {
+        Thread thread = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                try (FileWriter fileWriter = new FileWriter(filePath)) {
+                    fileWriter.write("Hello, world!");
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        });
+        thread.start();
+    }
+
+    public static void main(String[] args) {
+        String file = "src/main/resources/text.txt";
+
+        writeFile(file, "Hello, world!");
+
+        readFile(file);
+
+        // Sleep for a while to allow the threads to complete
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+}

core-java-modules/core-java-io-5/src/main/resources/read_file.txt

@@ -0,0 +1,5 @@
+Hello,
+Baeldung!
+Nice to meet you!
+My name is
+Wynn.

core-java-modules/core-java-io-5/src/main/resources/text.txt

@@ -0,0 +1 @@
+Hello, world!

core-java-modules/core-java-io-5/src/main/resources/write_file.txt

@@ -0,0 +1,5 @@
+Hello,
+Baeldung!
+Nice to meet you!
+My name is
+Wynn.