How to read a configuration file in Java

Question

I am doing a project to build thread pooled web server, in which I have to set

• the port number on which server listens.
• How many threads are there in thread pool
• Absolute Path of the root directory, and so many points.

One way is to hard code all these variables in the code, that I did. But professionally it is not good.

Now, I want to make one configuration file, in which I put all these data, and at the run time my code fetches these.

How can I make configuration file for the above task ?

Answer 1

app.config

app.name=Properties Sample Code app.version=1.09   

---

Source code:

Properties prop = new Properties(); String fileName = "app.config"; try (FileInputStream fis = new FileInputStream(fileName)) {     prop.load(fis); } catch (FileNotFoundException ex) {     ... // FileNotFoundException catch is optional and can be collapsed } catch (IOException ex) {     ... } System.out.println(prop.getProperty("app.name")); System.out.println(prop.getProperty("app.version")); 

---

Output:

Properties Sample Code 1.09   

Answer 2

Create a configuration file and put your entries there.

SERVER_PORT=10000      THREAD_POOL_COUNT=3      ROOT_DIR=/home/    

You can load this file using Properties.load(fileName) and retrieved values you get(key);