[BAEL-6955] finalization deprcation (#14932)

Co-authored-by: Bhaskar <bhaskar.dastidar@freshworks.com>
2023-10-10 01:29:52 +05:30
parent 0faf3ee42c
commit 8ffbb095da
8 changed files with 216 additions and 0 deletions
@@ -0,0 +1,27 @@
+package com.baeldung.finalization_closeable_cleaner;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+
+public class FinalizationExamples {
+    FileInputStream fis = null;
+
+    public void readFileOperationWithFinalization() throws IOException {
+        try {
+            fis = new FileInputStream("input.txt");
+            // perform operation on the file
+            System.out.println(fis.readAllBytes().length);
+
+        } finally {
+            if (fis != null)
+                fis.close();
+        }
+    }
+
+    public void readFileOperationWithTryWith() throws IOException {
+        try (FileInputStream fis = new FileInputStream("input.txt")) {
+            // perform operations
+            System.out.println(fis.readAllBytes().length);
+        }
+    }
+}
@@ -0,0 +1,48 @@
+package com.baeldung.finalization_closeable_cleaner;
+
+import java.lang.ref.Cleaner;
+
+public class MyCleanerResourceClass implements AutoCloseable {
+    private static Resource resource;
+
+    private static final Cleaner cleaner = Cleaner.create();
+    private final Cleaner.Cleanable cleanable;
+
+    public MyCleanerResourceClass() {
+        resource = new Resource();
+        this.cleanable = cleaner.register(this, new CleaningState());
+    }
+
+    public void useResource() {
+        // using the resource here
+        resource.use();
+    }
+
+    @Override
+    public void close() {
+        // perform actions to close all underlying resources
+        this.cleanable.clean();
+    }
+
+    static class CleaningState implements Runnable {
+        CleaningState() {
+            // constructor
+        }
+
+        @Override
+        public void run() {
+            // some cleanup action
+            System.out.println("Cleanup done");
+        }
+    }
+
+    static class Resource {
+        void use() {
+            System.out.println("Using the resource");
+        }
+
+        void close() {
+            System.out.println("Cleanup done");
+        }
+    }
+}
@@ -0,0 +1,25 @@
+package com.baeldung.finalization_closeable_cleaner;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
+public class MyCloseableResourceClass implements AutoCloseable {
+
+    private final FileInputStream fis;
+
+    public MyCloseableResourceClass() throws FileNotFoundException {
+        this.fis = new FileInputStream("src/main/resources/file.txt");
+
+    }
+
+    public int getByteLength() throws IOException {
+        System.out.println("Some operation");
+        return this.fis.readAllBytes().length;
+    }
+    @Override
+    public void close() throws IOException {
+        System.out.println("Finalized object");
+        this.fis.close();
+    }
+}
@@ -0,0 +1,24 @@
+package com.baeldung.finalization_closeable_cleaner;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
+public class MyFinalizableResourceClass {
+    private FileInputStream fis;
+
+    public MyFinalizableResourceClass() throws FileNotFoundException {
+        this.fis = new FileInputStream("src/main/resources/file.txt");
+    }
+
+    public int getByteLength() throws IOException {
+        System.out.println("Some operation");
+        return this.fis.readAllBytes().length;
+    }
+
+    @Override
+    protected void finalize() throws Throwable {
+        System.out.println("Finalized object");
+        this.fis.close();
+    }
+}
@@ -0,0 +1 @@
+This is a test file.