From 567637497c5aac2dc21c1946c74c246fe070d9f6 Mon Sep 17 00:00:00 2001
From: jbranchaud <jbranchaud@gmail.com>
Date: Mon, 14 Oct 2024 16:04:07 -0500
Subject: [PATCH] Add Ensure Resources Always Get Closed as a Java TIL

---
 README.md                                  |  3 +-
 java/ensure-resources-always-get-closed.md | 55 ++++++++++++++++++++++
 2 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 java/ensure-resources-always-get-closed.md

diff --git a/README.md b/README.md
index 7ba7bc6..bc2b30f 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1466 TILs and counting..._
+_1467 TILs and counting..._
 
 ---
 
@@ -442,6 +442,7 @@ _1466 TILs and counting..._
 
 ### Java
 
+- [Ensure Resources Always Get Closed](java/ensure-resources-always-get-closed.md)
 - [Install Java On Mac With Brew](java/install-java-on-mac-with-brew.md)
 - [Run A Hello World Program In Eclipse](java/run-a-hello-world-program-in-eclipse.md)
 
diff --git a/java/ensure-resources-always-get-closed.md b/java/ensure-resources-always-get-closed.md
new file mode 100644
index 0000000..2882e1c
--- /dev/null
+++ b/java/ensure-resources-always-get-closed.md
@@ -0,0 +1,55 @@
+# Ensure Resources Always Get Closed
+
+Java has a construct known as _try-with-resource_ that allows us to always
+ensure opened resources get closed. This is safer than similar cleanup in the
+`finally` block which could still leave a memory leak if an error occurs in
+that block.
+
+To use the _try-with-resource_ construct, instantiate your opened resource in
+parentheses with the `try`.
+
+```java
+try (BufferedReader reader = new BufferedReader(new FileReader(filename))) {
+  // ...
+}
+```
+
+The resource will be automatically closed when the try/catch block completes.
+
+Here is a full example:
+
+```java
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+
+public class FileReaderExample {
+    public static void main(String[] args) {
+        String fileName = "example.txt";
+        
+        try (BufferedReader reader = new BufferedReader(new FileReader(fileName))) {
+            String line;
+            int lineCount = 0;
+            
+            while ((line = reader.readLine()) != null && lineCount < 5) {
+                System.out.println(line);
+                lineCount++;
+            }
+        } catch (IOException e) {
+            System.out.println("An error occurred while reading the file: " + e.getMessage());
+        }
+    }
+}
+```
+
+You can even specify multiple resources in one `try`. The above does that, but
+this will make it more obvious:
+
+```java
+try (FileReader fr = new FileReader(filename);
+     BufferedReader br = new BufferedReader(fr)) {
+  // ...
+}
+```
+
+[source](https://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html)