how to load property file in java

In this post, we will learn how to load property file in java. Properties file is used to store and retrieve values from file.

It is stored as key and value pair. Below is an sample property file

database.properties

database.url=jdbc:mysql://localhost:3306/beginnersbug
database.username=root
database.password=password

Read properties from absolute path

import java.io.FileReader;
import java.util.Properties;

public class LoadProperty {

	public static void main(String[] args) {
		try {
			FileReader reader = new FileReader("D:\\BB\\Workspace\\database.properties");

			Properties p = new Properties();
			p.load(reader);

			System.out.println(p.getProperty("database.url"));
			System.out.println(p.getProperty("database.username"));
			System.out.println(p.getProperty("database.password"));

		} catch (Exception e) {
			e.printStackTrace();
		}

	}

}

Output

jdbc:mysql://localhost:3306/beginnersbug
root
password

Read properties from class path

Please make sure you have database.properties in class path. else you will get Please check the file present in classpath

Syntax

LoadPropertyFromClassPath.class.getResourceAsStream("database.properties");


import java.io.InputStream;
import java.util.Properties;

public class LoadPropertyFromClassPath {

	public static void main(String[] args) {
		try {
			Properties prop = new Properties();
			InputStream stream = LoadPropertyFromClassPath.class.getResourceAsStream("database.properties");
			if (stream != null) {
				prop.load(stream);
				System.out.println(prop.getProperty("database.url"));
				System.out.println(prop.getProperty("database.username"));
				System.out.println(prop.getProperty("database.password"));
			} else {
				System.err.println("Please check the file present in classpath");
			}

		} catch (Exception e) {
			e.printStackTrace();
		}

	}

}

Output

jdbc:mysql://localhost:3306/beginnersbug
root
password

Print all the values from property file

Syntax

prop.keySet().stream().map(key -> key + ": " + prop.getProperty(key.toString()))
						.forEach(System.out::println);

Example

import java.io.InputStream;
import java.util.Properties;

public class PrintPropertis {

	public static void main(String[] args) {
		try {
			Properties prop = new Properties();
			InputStream stream = LoadPropertyFromClassPath.class.getResourceAsStream("database.properties");
			if (stream != null) {
				prop.load(stream);
				prop.keySet().stream().map(key -> key + ": " + prop.getProperty(key.toString()))
						.forEach(System.out::println);
			} else {
				System.err.println("Please check the file present in classpath");
			}

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}

Output

database.password: password
database.url: jdbc:mysql://localhost:3306/beginnersbug
database.username: root

Github

https://github.com/rkumar9090/BeginnersBug/blob/master/BegineersBug/src/com/geeks/example/LoadProperty.java

https://github.com/rkumar9090/BeginnersBug/blob/master/BegineersBug/src/com/geeks/example/LoadPropertyFromClassPath.java

https://github.com/rkumar9090/BeginnersBug/blob/master/BegineersBug/src/com/geeks/example/PrintPropertis.java

database.properties

Read properties from absolute path

Output

Read properties from class path

Syntax

Output

Print all the values from property file

Syntax

Example

Output

Github

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