☕🖥️ SCRIPTING in JAVA 25: 🔟 SH/BAT jobs done in Java
☕🖥️ SCRIPTING in JAVA 25: 🔟 SH/BAT jobs done in Java
Your next sysadmin script can be a single .java file.
🔸 TLDR
Java 25 makes Java surprisingly practical for scripting.
▪️ No explicit class required
▪️ void main() is enough
▪️ Run directly with java Script.java
▪️ Compact source files automatically import the public APIs exported by java.base
Here are 🔟 everyday SH/BAT-style scripts written as minimal Java 25 files.
📃 1️⃣ LIST A DIRECTORY
Java 25 snippet: List.java
void main(String[] args) throws Exception { try (var files = Files.list(Path.of(args.length == 0 ? "." : args[0]))) { files.forEach(System.out::println); } }
Equivalent to a basic ls / dir.
Run:
java List.java .
🔎 2️⃣ FIND FILES RECURSIVELY
Java 25 snippet: Find.java
void main(String[] args) throws Exception { try (var files = Files.walk(Path.of(args[0]))) { files.filter(p -> p.toString().endsWith(args[1])) .forEach(System.out::println); } }
Find matching files through a directory tree.
Run:
java Find.java logs .log
👓 3️⃣ GREP A TEXT FILE
Java 25 snippet: Grep.java
void main(String[] args) throws Exception { try (var lines = Files.lines(Path.of(args[0]))) { lines.filter(l -> l.contains(args[1])) .forEach(System.out::println); } }
A minimal Java equivalent of grep.
Run:
java Grep.java app.log ERROR
©️ 4️⃣ COPY A FILE
Java 25 snippet: Copy.java
Exception { Files.copy( Path.of(args[0]), Path.of(args[1]), StandardCopyOption.REPLACE_EXISTING ); }
Copy a file and replace the destination if it already exists.
Run:
java Copy.java app.log backup.log
🚚 5️⃣ MOVE OR RENAME A FILE
Java 25 snippet: Move.java
void main(String[] args) throws Exception { Files.move( Path.of(args[0]), Path.of(args[1]), StandardCopyOption.REPLACE_EXISTING ); }
The scripting equivalent of mv or move.
Run:
java Move.java old.log archive.log
🗑️ 6️⃣ DELETE OLD LOGS
Java 25 snippet: CleanLogs.java
void main(String[] args) throws Exception { var limit = Instant.now().minus(Duration.ofDays(7)); try (var files = Files.find(Path.of(args[0]), 99, (p, a) -> p.toString().endsWith(".log") && a.lastModifiedTime().toInstant().isBefore(limit))) { files.forEach(p -> p.toFile().delete()); } }
Recursively remove .log files older than seven days.
Run:
java CleanLogs.java logs
📊 7️⃣ CHECK FREE DISK SPACE
Java 25 snippet: Disk.java
void main() throws Exception { var disk = Files.getFileStore(Path.of(".")); System.out.printf( "Free: %.2f GB%n", disk.getUsableSpace() / 1_000_000_000.0 ); }
Quick disk-space check without invoking an OS command.
Run:
java Disk.java
🌐 8️⃣ CHECK AN HTTP ENDPOINT
Java 25 snippet: HttpCheck.java
void main(String[] args) throws Exception { var c = (HttpURLConnection) URI.create(args[0]).toURL().openConnection(); c.setConnectTimeout(3000); System.out.println(c.getResponseCode()); }
Call an HTTP endpoint and print its response status.
Run:
java HttpCheck.java https://spring.io
🔌 9️⃣ CHECK A TCP PORT
Java 25 snippet: PortCheck.java
void main(String[] args) { try (var socket = new Socket()) { socket.connect( new InetSocketAddress(args[0], Integer.parseInt(args[1])), 2000 ); System.out.println("OPEN"); } catch (IOException e) { System.out.println("CLOSED"); } }
Test whether a host/port can be reached.
Run:
java PortCheck.java localhost 8080
▶️ 🔟 RUN AN OS COMMAND
Java 25 snippet: Run.java
void main(String[] args) throws Exception { var exit = new ProcessBuilder(args) .inheritIO() .start() .waitFor(); System.exit(exit); }
Execute another program while forwarding its console and exit code.
Linux:
java Run.java ping -c 3 localhost
Windows:
java Run.java cmd /c dir;
🔸 TAKEAWAYS
▪️ Java 25 can now feel much closer to a scripting language for small utilities.
▪️ java MyScript.java means no explicit javac step is required.
▪️ Compact source files remove the class boilerplate and allow void main().
▪️ You still get Java APIs for files, networking, processes, dates and streams.
▪️ SH/BAT remains perfect for tiny OS-specific commands. Java becomes interesting when the script starts growing into actual logic.
Maybe the boundary between "script" and "Java program" just became much thinner. ☕
#Java #Java25 #JDK25 #OpenJDK #Scripting #Automation #DevOps #SysAdmin
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