Essential Linux Commands Every Java Developer Should Master

Java developers often need to work with Linux servers, so mastering a core set of shell commands is essential. This guide provides practical examples and explanations for frequently used commands without exhaustive detail; users can consult --help or search online for deeper options.

1. Find Files

find / -name filename.txt

– locate filename.txt from the root directory. find . -name "*.xml" – recursively list all XML files. find . -name "*.xml" | xargs grep "hello world" – find XML files containing the phrase “hello world”. grep -H 'spring' *.xml – show XML files that contain the word “spring”. find ./ -size 0 | xargs rm -f & – delete zero‑byte files.

2. Check If a Program Is Running

ps -ef | grep tomcat

– list processes related to Tomcat.

3. Terminate a Process

kill -9 19979

– force‑kill the process with PID 19979.

4. List Files (including hidden)

ls -al

5. Show Current Directory

pwd

6. Copy Files

cp source dest

– copy a single file. cp -r sourceFolder targetFolder – recursively copy a directory. scp sourceFile remoteUser@remoteIp:remotePath – copy a file to a remote host.

7. Create and Delete Directories

mkdir newfolder

– create a new directory. rmdir deleteEmptyFolder – remove an empty directory. rm -rf deleteFile – recursively delete a directory and its contents.

8. Move or Rename Files

mv /temp/movefile /targetFolder

– move a file. mv oldNameFile newNameFile – rename a file.

9. Switch User

su -username

10. Change File Permissions

chmod 777 file.java

– set read/write/execute for everyone (displayed as -rwxrwxrwx).

11. Archive and Compress

tar -czf test.tar.gz /test1 /test2

– create a gzipped tarball. tar -tzf test.tar.gz – list contents of the tarball. tar -xvzf test.tar.gz – extract the archive.

12. View File Head/Tail

head -n 10 example.txt

– show the first 10 lines. tail -n 10 example.txt – show the last 10 lines. tail -f example.log – follow a log file, displaying new lines as they appear.

13. Network Utilities

netstat -tln | grep 8080

– check if port 8080 is listening. lsof -i :8080 – identify the process using port 8080. ping www.just-ping.com – test connectivity to a host. wget http://file.tgz or curl http://file.tgz – download a file. ssh userName@ip – log into a remote machine via SSH.

14. Display Environment Variables

echo $JAVA_HOME

– print the value of the JAVA_HOME variable.

15. Common Java Commands

Utilities such as java, javac, jps, jstat, jmap, and jstack are frequently used for compiling, monitoring, and debugging Java applications.

16. Other Useful Tools

Version control and build tools like svn, git, and maven are also essential in daily development workflows.

Reference Links

Linux port conflict resolution: http://www.hollischuang.com/archives/239

Powerful find/grep usage: https://linux.cn/article-1672-1.html

General Linux command guide: https://blog.csdn.net/tianshijianbing1989/article/details/40780463