Java67
Learn Java and Programming through articles, code examples, and tutorials for developers of all levels.
Friday, December 13, 2024
[Solved] 3 Examples to reverse an Array in Java - Example Tutorial
How to Find Even and Odd Number in Java - Program Tutorial Example
Wednesday, December 11, 2024
How to Find Missing Number in a Sorted Array in Java [Solved]
How to Count number of 1s (Set Bits) in a binary number in Java [Solved]
How to Print Pyramid Pattern in Java? Program Example
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You need to write a Java program to print the above pyramid pattern. How many levels the pyramid triangle would have will be decided by the user input. You can print this kind of pattern by using print() and println() method from System.out object. System.out.print() just prints the String or character you passed to it, without adding a new line, useful to print stars in the same line.
Monday, December 9, 2024
Top 20 Machine Learning Libraries for AI Engineers in 2025 - Best of Lot
Artificial Intelligence (AI) has emerged as a transformative technology, revolutionizing various industries and driving innovation. With the increasing accessibility of AI, numerous free tools have become available, enabling individuals and businesses to explore and leverage AI capabilities. In this article, we present the top 20 free Machine Learning libraries to try in 2025. These tools cover a wide range of AI applications, including machine learning, natural language processing, computer vision, and more. Let's dive into the exciting world of AI tools and discover how they can empower innovation and automation.
Sunday, December 8, 2024
How to call REST API an send HTTP GET and POST Request using cURL command in Linux? Example Tutorial
Thursday, October 31, 2024
How to Create Config Server in Microservices Architecture with Spring Cloud Config Server
The ability of microservices architecture to deconstruct big monolithic programmes into smaller, independent, and controllable services has led to its enormous growth in popularity in recent years. It can be difficult to manage configuration across numerous microservices, though, as each service may call for a separate set of configurations. To solve this problem, configurations for microservices are centralised and managed by a separate Config Server. In this post, we'll examine what a Config Server is, why it's crucial for microservices, and how to use Spring Cloud Config Server to construct it.
Tuesday, October 29, 2024
Top 10 AI Tools for Bloggers and Writers in 2025
Artificial Intelligence (AI) has revolutionized various industries, and the field of writing and blogging is no exception. AI-powered tools for bloggers and writers have emerged, offering innovative solutions to enhance creativity, streamline workflows, and improve content quality. In this article, we present the top 10 AI tools specifically designed for bloggers and writers. These tools leverage AI technologies such as natural language processing, machine learning, and data analytics to help writers generate ideas, improve grammar, enhance productivity, and optimize content for better engagement. Let's explore these cutting-edge AI tools and discover how they can empower bloggers and writers.
Monday, October 28, 2024
What is Payload in REST API? How to send Payload using HTTP Post Request and HttpClient
Hello and welcome to the blog post. In this comprehensive article we are going to take a look at an interesting topic. I’m sure you all are familiar with client-server architecture. If not let me recap it quickly for you.
A Client is a machine (or a web-browser) that request for desired results from the server. In other words, clients initiate requests for services or resources, while servers provide those services or resources upon request. The client-server model forms the foundation of many networked applications and systems, where clients and servers communicate and collaborate to fulfill various tasks and deliver services.
What is a Payload?
When a client sends a request to a server, the payload typically contains the data or parameters required by the server to process the request. For example, in a client-server architecture for a web application, the payload of an HTTP request sent by the client may include parameters for a form submission, JSON data for an API request, or a file to be uploaded.
On the server side, when the server sends a response back to the client, the payload contains the data or information requested by the client. This can include HTML content, JSON responses, file attachments, or any other data relevant to the specific request made by the client.
Payload in REST API
The information supplied in the body of an HTTP request is referred to as a payload in the RESTful API architecture. It represents the data that is being sent from the client to the server or the other way around. Depending on the content type supplied in the request headers, the payload may be in one of several forms, including JSON, XML, or plain text.
The payload carries the necessary data required to perform operations on the server or to retrieve specific resources. For example, when creating a new resource, the payload would typically contain the data that needs to be stored on the server. When updating an existing resource, the payload would include the modified data.
What is an HttpClient?
HttpClient is a powerful Java package that offers quick and efficient way for submitting HTTP requests and receiving server responses. Starting with Java 11, it is a part of the Java SE standard library and offers a comprehensive API for interacting with HTTP-based services.
HttpClient's main objective is to make it easier for client applications to communicate with RESTful APIs, web services, and other HTTP-based endpoints. The low-level aspects of creating and managing connections, dealing with request and response bodies, modifying headers, controlling timeouts, and dealing with redirection are abstracted away.
You can perform various HTTP operations like GET, POST, PUT, DELETE by using HttpClient. It supports both synchronous and asynchronous request processing and offers a number of configuration options for customization.
Let’s take an example on how to send a POST request to REST API using HttpClient
import com.fasterxml.jackson.databind.ObjectMapper;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpHeaders;
import java.net.http.HttpResponse.BodyHandlers;
public class HttpClientExample {
public static void main(String[] args) throws Exception {
// Create an instance of HttpClient
HttpClient httpClient = HttpClient.newHttpClient();
// Define the URL of the REST API endpoint
String url = "http://api.example.com/users";
// Create a User object
User user = new User("John Doe", 30);
// Serialize the User object to JSON
ObjectMapper objectMapper = new ObjectMapper();
String requestBody = objectMapper.writeValueAsString(user);
// Build the HTTP request
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create(url))
.header("Content-Type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString(requestBody))
.build();
// Send the request and receive the response
HttpResponse<String> response = httpClient.send(request, BodyHandlers.ofString());
// Extract the User object from the response
String responseBody = response.body();
User responseUser = objectMapper.readValue(responseBody, User.class);
// Print the response User object
System.out.println("Response User: " + responseUser);
}
}
class User {
private String name;
private int age;
// Constructors, getters, and setters
@Override
public String toString() {
return "User{" +
"name='" + name + '\'' +
", age=" + age +
'}';
}
}
In this example, we have a User class representing the user object. We use the ObjectMapper from the Jackson library to serialize the User object to JSON format.
We then create an HttpRequest object with the necessary details, including the URI, headers (in this case, "Content-Type" is set to "application/json"), and the request body containing the serialized User object.
After sending the request using httpClient.send(), we receive the response as an HttpResponse object. We extract the response body as a JSON string.
Finally, we deserialize the response JSON string back into a User object using objectMapper.readValue(). The resulting User object represents the response payload, which we can use as needed.
Sending Payload to REST API using HTTP POST Request and HttpClient in Java
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpHeaders;
import java.net.http.HttpEntity;
import java.net.http.HttpHeaders;
import java.net.http.HttpRequest.BodyPublishers;
import java.net.http.HttpResponse.BodyHandlers;
public class HttpClientExample {
public static void main(String[] args) throws Exception {
HttpClient httpClient = HttpClient.newHttpClient();
String jsonPayload = "{\"name\": \"Someone \", \"email\": \"someone@example.com\"}";
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("http://example.com/api/resource"))
.header("Content-Type", "application/json")
.POST(BodyPublishers.ofString(jsonPayload))
.build();
HttpResponse<String> response = httpClient.send(request, BodyHandlers.ofString());
int statusCode = response.statusCode();
String responseBody = response.body();
System.out.println("Status Code: " + statusCode);
System.out.println("Response Body: " + responseBody);
}
}
In the example above, we create a JSON payload using a sample data object. We set the HTTP method to POST, the request URL to "http://example.com/api/resource", and the content type to "application/json". The payload is then sent in the body of the request using the BodyPublishers.ofString() method.
Finally, we retrieve and handle the response from the server.
Remember to replace "http://example.com/api/resource" with the actual endpoint URL of the REST API you want to send the payload to, and modify the payload data according to your requirements and the API's expected format.
Let me show you how to send other types of payloads from the following example.
1) Sending a Form-UrlEncoded Payload
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpHeaders;
import java.net.http.HttpEntity;
import java.net.http.HttpHeaders;
import java.net.http.HttpRequest.BodyPublishers;
import java.net.http.HttpResponse.BodyHandlers;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
public class HttpClientExample {
public static void main(String[] args) throws Exception {
HttpClient httpClient = HttpClient.newHttpClient();
String payload = "name=" + URLEncoder.encode("John Doe", StandardCharsets.UTF_8)
+ "&email=" + URLEncoder.encode("johndoe@example.com", StandardCharsets.UTF_8);
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("http://example.com/api/resource"))
.header("Content-Type", "application/x-www-form-urlencoded")
.POST(BodyPublishers.ofString(payload))
.build();
HttpResponse<String> response = httpClient.send(request, BodyHandlers.ofString());
int statusCode = response.statusCode();
String responseBody = response.body();
System.out.println("Status Code: " + statusCode);
System.out.println("Response Body: " + responseBody);
}
}
In this example, we are sending a form-urlencoded payload to the REST API endpoint "http://example.com/api/resource". The payload contains two fields, name and email, which are URL-encoded using the URLEncoder.encode() method. The Content-Type header is set to "application/x-www-form-urlencoded".
2) Sending a Plain Text Payload
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpHeaders;
import java.net.http.HttpEntity;
import java.net.http.HttpHeaders;
import java.net.http.HttpRequest.BodyPublishers;
import java.net.http.HttpResponse.BodyHandlers;
public class HttpClientExample {
public static void main(String[] args) throws Exception {
HttpClient httpClient = HttpClient.newHttpClient();
String textPayload = "This is a plain text payload.";
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("http://example.com/api/resource"))
.header("Content-Type", "text/plain")
.POST(BodyPublishers.ofString(textPayload))
.build();
HttpResponse<String> response = httpClient.send(request, BodyHandlers.ofString());
int statusCode = response.statusCode();
String responseBody = response.body();
System.out.println("Status Code: " + statusCode);
System.out.println("Response Body: " + responseBody);
}
}
In this example, we are sending a plain text payload to the REST API endpoint "http://example.com/api/resource". The payload simply contains the text "This is a plain text payload." The Content-Type header is set to "text/plain" to indicate that the payload is in plain text format.
Summary
In summary, sending a payload to a REST API using an HTTP POST request and HttpClient in Java involves creating an HTTP request with the desired payload, specifying the necessary headers, and sending the request using the HttpClient instance. The server will process the payload and provide a response, which can be accessed and utilized accordingly.
Sunday, October 27, 2024
20 Examples of Git Commands in Linux and Windows
Version control is crucial in software development, and Git stands out as a powerful tool for managing source code. Whether you're working in a Linux or Windows environment, understanding Git commands is essential. This article explores 20 fundamental Git commands, demonstrating their application and significance. From initializing a repository to handling branches and commits, each command plays a pivotal role in maintaining a well-organized and collaborative development workflow. Whether you're a seasoned developer or a newcomer, mastering these Git commands will enhance your ability to track changes, collaborate seamlessly, and contribute effectively to software projects.
Friday, October 25, 2024
Is Frontend Master Worth It?
Frontend development has been growing rapidly in the last few years, as web applications have become more complex and interactive. Frontend Master is an online platform that provides courses and tutorials to learn front-end development. However, with so many resources available on the internet, it's difficult to know whether Frontend Master is worth investing your time and money. In this article, we'll take a closer look at what Frontend Master has to offer and whether it's worth the investment.
Saturday, October 19, 2024
Top 10 Programming Languages to Learn in 2025 [UPDATED]
Monday, October 14, 2024
5 Best DP-900 Certification Courses and Practice Test for Azure Data Fundamentals Exam in 2025
The DP-900 certification, also known as the Microsoft Azure Data Fundamentals Certification, is perfect for people who are just starting to work with data on the cloud. This certification will help you build foundational knowledge in cloud data services with Microsoft Azure. Taking the DP-900 certification exam will have many benefits. It will give you a broad overview of how data works in the cloud. It will also help you test your knowledge of cloud data within the ambit of Microsoft Azure services.
Wednesday, October 9, 2024
10 Tools Java Developers Should Learn in 2024 - (UPDATED)
Wednesday, October 2, 2024
7 Free 1Z0-803 and 1Z0-804 Sample Questions - OCAJP 7 and OCPJP 7 Mock Exams (Oracle Certified Associate Java SE 7 Programmer 1 and 2 )
Top 5 OCPJP7 books for 1Z0-804 and 1Z0-805 Exam - Java SE 7 II Certification
Monday, September 30, 2024
When to use PUT or POST in a RESTful API and Web Service? Answer
Thursday, September 19, 2024
Review - Is IT Fundamentals for Cybersecurity Specialization on Coursera Worth it?
Learning the information technology (IT) fundamentals in general and cyber security is a good investment in yourself since there is a massive demand for these skills. Companies need people to secure their infrastructure, such as their servers where they host the website and user's data, monitor their network for unauthorized access, and scan the employee computers for any trojan and viruses that could give hackers control over your system.
Tuesday, September 17, 2024
What is Backend for front-end Pattern? How to use it?
In the realm of microservices architecture, designing efficient communication between front-end applications and the back-end services is crucial. The Backend for Front-End (BFF) pattern has emerged as a useful architectural pattern to streamline this communication. In this article, we will delve into what the Backend for Front-End pattern is, its benefits, and how to effectively implement and utilize it in your microservices ecosystem.