Properties

import java.util.Map;
import java.util.Properties;
import java.util.Set;

/**
 * Java program to demonstrate Properties class to get all the system properties
 */
public class PropertiesExample2GetSystemProperties {
    /**
     * Main method for Demo
     *
     * @param args input arguments
     */
    public static void main(String[] args) {
        // get all the system properties
        Properties p = System.getProperties();

        // stores set of properties information
        Set<Map.Entry<Object, Object>> set = p.entrySet();

        // iterate over the set
        for (Map.Entry<Object, Object> entry : set) {
            // print each property
            System.out.printf("%s=%s\n", entry.getKey(), entry.getValue());
        }
    }
}

import java.io.FileReader;
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Properties;

/**
 * Java program to demonstrate Properties class to get information from the properties file
 */
public class PropertiesExample1 {
    /**
     * Main method for Demo
     *
     * @param args input arguments
     * @throws IOException throw IOException when work with IO
     */
    public static void main(String[] args) throws IOException {
        // get path for user.properties
        Path userPropertiesPath =
                Paths.get("src", "main", "resources", "example", "properties", "account.properties");

        // create a reader object on the properties file
        FileReader reader = new FileReader(userPropertiesPath.toFile());

        // create properties object
        Properties p = new Properties();

        // Add a wrapper around reader object
        p.load(reader);

        // access properties data
        System.out.printf("Username: '%s'\n", p.getProperty("username"));
        System.out.printf("Password: '%s'\n", p.getProperty("password"));
    }
}

import java.io.FileWriter;
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Properties;

/**
 * Java program to demonstrate Properties class to create the properties file
 */
public class PropertiesExample3CreateAndWriteToFile {
    /**
     * Main method for Demo
     *
     * @param args input arguments
     * @throws IOException throw IOException when work with IO
     */
    public static void main(String[] args) throws IOException {
        // create an instance of Properties
        Properties p = new Properties();

        // add properties to it
        p.setProperty("name", "Dmitry Rakovets");
        p.setProperty("email", "dmitryrakovets@gmail.com");

        // get path for account.properties
        Path userPropertiesPath =
                Paths.get("src", "main", "resources", "example", "properties", "user.properties");

        // store the properties to a file
        p.store(new FileWriter(userPropertiesPath.toFile()), "Properties Example");
    }
}