Categories
java properties

how to write properties file in java

In this tutorial, we will learn how to write properties file in java

we are going to use FileOutputStream to write in file. It is going to write on classpath

Syntax
properties.store(new FileOutputStream("database.properties"), "Comments: Updated from java");
Example Create new property file
import java.io.FileOutputStream;
import java.util.Properties;

public class WriteProperties {

	public static void main(String[] args) {
		try {

			Properties properties = new Properties();
			properties.setProperty("database.url", "jdbc:mysql://localhost:3306/beginnersbug");
			properties.setProperty("database.username", "root");
			properties.setProperty("database.password", "password");
			properties.store(new FileOutputStream("database.properties"), "Comments: Updated from java");
			System.out.println("File has writen successfully");
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

}
Output
File has writen successfully
Github

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

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how to load property file in java

 

Categories
java properties

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

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