Convert Properties to Map in Java

🎓 Top 15 Udemy Courses (80-90% Discount): My Udemy Courses - Ramesh Fadatare — All my Udemy courses are real-time and project oriented courses.

▶️ Subscribe to My YouTube Channel (178K+ subscribers): Java Guides on YouTube

▶️ For AI, ChatGPT, Web, Tech, and Generative AI, subscribe to another channel: Ramesh Fadatare on YouTube

1. Introduction

Properties in Java are often used to manage application settings and configurations through key-value pairs stored in a simple, file-based format. However, there might be scenarios where you need to manipulate these configurations as a Map for enhanced functionality, such as leveraging Java Stream API operations or integrating with APIs that require maps. This blog post will demonstrate how to convert Properties to a Map, facilitating operations that are more complex or not directly supported by the Properties class.

2. Program Steps

1. Create and populate a Properties object.

2. Convert the Properties object to a Map<String, String>.

3. Display the resulting Map.

3. Code Program

import java.util.*;
import java.util.stream.Collectors;

public class PropertiesToMap {
    public static void main(String[] args) {
        // Step 1: Creating and populating a Properties object
        Properties properties = new Properties();
        properties.setProperty("database.url", "jdbc:mysql://localhost:3306/myDb");
        properties.setProperty("database.user", "user1");
        properties.setProperty("database.password", "pass123");

        // Step 2: Converting Properties to Map<String, String>
        Map<String, String> map = properties.entrySet().stream()
                .collect(Collectors.toMap(
                        e -> e.getKey().toString(),
                        e -> e.getValue().toString()));

        // Step 3: Displaying the resulting Map
        System.out.println("Map from Properties: " + map);
    }
}

Output:

Map from Properties: {database.password=pass123, database.url=jdbc:mysql://localhost:3306/myDb, database.user=user1}

Explanation:

1. The program starts by creating a Properties object and populating it with key-value pairs that represent hypothetical database configuration settings. The Properties class, which extends Hashtable<Object,Object>, allows for the storage of strings in a key-value format.

2. To convert the Properties object into a Map<String, String>, the program utilizes the Java Stream API. The properties.entrySet().stream() call creates a stream of Map.Entry objects. Each entry's key and value are converted to strings using the toString method. The stream is then collected into a new Map<String, String> using Collectors.toMap(), which requires functions to extract the key and value for each map entry.

3. Finally, the resulting Map is printed to the console. This Map contains all the key-value pairs from the original Properties object, now accessible in a format that supports a broader range of operations and manipulations provided by the Map interface.

4. This example demonstrates a practical use case for converting Properties to a Map<String, String> in Java, leveraging the Stream API for efficient transformation and facilitating enhanced data processing capabilities.

My Top and Bestseller Udemy Courses. The sale is going on with a 70 - 80% discount. The discount coupon has been added to each course below:

Build REST APIs with Spring Boot 4, Spring Security 7, and JWT

🆕 High-Demand 80–90% OFF

[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25

🆕 High-Demand 80–90% OFF

ChatGPT + Generative AI + Prompt Engineering for Beginners

🚀 Trending Now 80–90% OFF

Spring 7 and Spring Boot 4 for Beginners (Includes 8 Projects)

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Real-Time REST APIs with Spring Boot - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Microservices with Spring Boot and Spring Cloud

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Java Full-Stack Developer Course with Spring Boot and React JS

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Build 5 Spring Boot Projects with Java: Line-by-Line Coding

🌟 Top Rated 80–90% OFF

Testing Spring Boot Application with JUnit and Mockito

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot Thymeleaf Real-Time Web Application - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Master Spring Data JPA with Hibernate

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot + Apache Kafka Course - The Practical Guide

🎓 Student Favorite 80–90% OFF
Available in Udemy for Business

Java Testing: Mastering JUnit 5 Framework

🆕 New 80–90% OFF

Reactive Programming in Java: Spring WebFlux and Testing

🌟 Top Rated 80–90% OFF

Spring Boot + RabbitMQ Course - The Practical Guide

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Functional Programming in Java (Includes Java Collections)

🎓 Student Favorite 80–90% OFF

ChatGPT for Java Developers: Boost Your Productivity with AI

🚀 Trending Now 80–90% OFF