Tag: java

Aws Lambda Java Example Code: Post, Get, Put, Delete

Aws Lambda Java Post example code

Here is an example of an AWS Lambda function written in Java that handles an HTTP POST request and returns a JSON response:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    private final ObjectMapper objectMapper = new ObjectMapper();

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();
        try {
            // parse the post data
            JsonNode postData = objectMapper.readTree((String) input.get("body"));

            // do something with the data
            String name = postData.get("name").asText();
            Response responseBody = new Response("Hello, " + name);

            return ApiGatewayResponse.builder()
                    .setStatusCode(200)
                    .setObjectBody(responseBody)
                    .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                    .build();
        } catch (IOException e) {
            logger.log(e.getMessage());
            return ApiGatewayResponse.builder()
                    .setStatusCode(500)
                    .setObjectBody("Error while parsing input: " + e.getMessage())
                    .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                    .build();
        }
    }
}

In this example, the class MyLambdaFunction implements the RequestHandler interface, which is provided by the AWS Lambda Java SDK. The class takes in two parameters: Map and Context, which represent the input to the function and the runtime context of the function, respectively.

The function uses the ObjectMapper class to parse the request body as a JSON object and extract the name property. It then creates an instance of the Response class with the message “Hello, ” + name and returns it as the response to the request.

You would need to create a new Lambda function in the AWS Lambda console and then upload the JAR file containing this code. After that, you would need to configure an API Gateway trigger to handle the incoming POST request and route it to your Lambda function.

It’s important to note that this is just a basic example and depending on your use case you might need to handle authentication, validation, error handling and other requirements.
You might also need to import the classes used on this example like com.amazonaws.services.lambda.runtime.Context, com.amazonaws.services.lambda.runtime.LambdaLogger, com.amazonaws.services.lambda.runtime.RequestHandler and other.

Aws Lambda Java Get Header example code

Here is an example of an AWS Lambda function written in Java that retrieves and parses headers from an HTTP request:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;

import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();

        // Retrieve headers from input
        Map headers = (Map)input.get("headers");

        // Parse specific header
        String myHeader = headers.get("my-header");

        // Do something with the header value
        Response responseBody = new Response("Hello, " + myHeader);

        return ApiGatewayResponse.builder()
                .setStatusCode(200)
                .setObjectBody(responseBody)
                .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                .build();
    }
}

This example retrieves the headers from the input object, which is passed as the first argument to the Lambda function. It then uses the get() method to retrieve the value of a specific header, in this case “my-header”, and save it to a variable. Then the function creates an instance of the Response class with the message “Hello, ” + myHeader and returns it as the response to the request.

You would need to create a new Lambda function in the AWS Lambda console and then upload the JAR file containing this code. After that, you would need to configure an API Gateway trigger to handle the incoming GET request and route it to your Lambda function.

It’s important to note that this is just a basic example and depending on your use case you might need to handle authentication, validation, error handling and other requirements.
You might also need to import the classes used on this example like com.amazonaws.services.lambda.runtime.Context, com.amazonaws.services.lambda.runtime.LambdaLogger, com.amazonaws.services.lambda.runtime.RequestHandler and other.

Aws Lambda Java get Example code

Here is an example of an AWS Lambda function written in Java that handles an HTTP GET request and returns a JSON response:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;

import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();

        // Retrieve query string parameters
        Map queryParams = (Map)input.get("queryStringParameters");

        // Retrieve name
        String name = queryParams.get("name");

        // Do something with the query string parameters
        Response responseBody = new Response("Hello, " + name);

        return ApiGatewayResponse.builder()
                .setStatusCode(200)
                .setObjectBody(responseBody)
                .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                .build();
    }
}

This example retrieves the query string parameters from the input object, which is passed as the first argument to the Lambda function. It then uses the get() method to retrieve the value of the name parameter and saves it to a variable. Then the function creates an instance of the Response class with the message “Hello, ” + name and returns it as the response to the request.

Aws Lambda Java Put Example code

Here is an example of an AWS Lambda function written in Java that handles an HTTP PUT request and returns a JSON response:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    private final ObjectMapper objectMapper = new ObjectMapper();

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();
        try {
            // parse the put data
            JsonNode putData = objectMapper.readTree((String) input.get("body"));

            // do something with the data
            String name = putData.get("name").asText();
            Response responseBody = new Response("Hello, " + name);

            return ApiGatewayResponse.builder()
                    .setStatusCode(200)
                    .setObjectBody(responseBody)
                    .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                    .build();
        } catch (IOException e) {
            logger.log(e.getMessage());
            return ApiGatewayResponse.builder()
                    .setStatusCode(500)
                    .setObjectBody("Error while parsing input: " + e.getMessage())
                    .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                    .build();
        }
    }
}

In this example, the class MyLambdaFunction implements the RequestHandler interface, which is provided by the AWS Lambda

Aws Lambda Java Delete Example code

Here is an example of an AWS Lambda function written in Java that handles an HTTP DELETE request and returns a JSON response:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;

import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();

        // Retrieve query string parameters
        Map queryParams = (Map)input.get("queryStringParameters");

        // Retrieve id
        String id = queryParams.get("id");

        // Delete the item
        deleteItem(id);

        // Create a response
        Response responseBody = new Response("Successfully deleted item with id: " + id);

        return ApiGatewayResponse.builder()
                .setStatusCode(200)
                .setObjectBody(responseBody)
                .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                .build();
    }
}

This example retrieves the query string parameters from the input object, which is passed as the first argument to the Lambda function. It then uses the get() method to retrieve the value of the id parameter and saves it to a variable. It then calls the deleteItem(id) function to delete the item from the database. Finally, it creates an instance of the Response class with the message “Successfully deleted item with id: ” + id and returns it as the response to the request.

You would need to create a new Lambda function in the AWS Lambda console and then upload the JAR file containing this code. After that, you would need to configure an API Gateway trigger to handle the incoming DELETE request and route it to your Lambda function.

Aws Lambda Java Patch example code

Here is an example of an AWS Lambda function written in Java that handles an HTTP PATCH request and returns a JSON response:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    private final ObjectMapper objectMapper = new ObjectMapper();

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();
        try {
            // parse the patch data
            JsonNode patchData = objectMapper.readTree((String) input.get("body"));

            // do something with the data
            String id = patchData.get("id").asText();
            String newValue = patchData.get("new_value").asText();
            updateItem(id, newValue);

            Response responseBody = new Response("Successfully updated

DateTimeFormat Spring Boot example

Spring Example @datetimeformat(pattern = yyyy-mm-dd )

Here is an example of how you might use the @DateTimeFormat annotation in a Spring application:

import org.springframework.format.annotation.DateTimeFormat;

public class Event {
    private String name;
    @DateTimeFormat(pattern = "yyyy-MM-dd")
    private LocalDate date;

    // constructor, getters, and setters...
}

This example creates a class called Event with a name and a date field. The @DateTimeFormat annotation is used to specify that the date field should be formatted as a date in the yyyy-MM-dd format when it is displayed or parsed.

You can use this annotation in combination with Spring’s @Controller and @RequestMapping annotations to specify the format of the date when it is received as a request parameter or when it is included in the model for a view.

For example, you might have a controller method like this:

@PostMapping("/events")
public String createEvent(@ModelAttribute @Valid Event event, BindingResult bindingResult, Model model) {
    if (bindingResult.hasErrors()) {
        return "form";
    }
    // save the event and redirect to the events list
    return "redirect:/events";
}

In this example, the createEvent method handles a POST request to the /events URL and creates a new Event object from the request parameters. The @DateTimeFormat annotation specifies that the date field should be parsed as a date in the yyyy-MM-dd format.

DateTimeFormat Spring Boot example

Here is an example of how you might use the @DateTimeFormat annotation in a Spring Boot application:

import org.springframework.format.annotation.DateTimeFormat;

@Entity
public class Event {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;

    @DateTimeFormat(pattern = "yyyy-MM-dd")
    private LocalDate date;

    // constructor, getters, and setters...
}

@DateTimeFormat annotation is used to specify that the date field should be formatted as a date in the yyyy-MM-dd format when it is displayed or parsed.

You can use this annotation in combination with Spring Boot’s @Controller and @RequestMapping annotations to specify the format of the date when it is received as a request parameter or when it is included in the model for a view.

For example, you might have a controller method like this:

@PostMapping("/events")
public String createEvent(@ModelAttribute @Valid Event event, BindingResult bindingResult, Model model) {
    if (bindingResult.hasErrors()) {
        return "form";
    }
    eventRepository.save(event);
    return "redirect:/events";
}

In this example, the createEvent method handles a POST request to the /events URL and creates a new Event object from the request parameters. The @DateTimeFormat annotation specifies that the date field should be parsed as a date in the yyyy-MM-dd format. The eventRepository.save(event) method saves the Event object to the database, and the user is redirected to the /events URL.

@datetimeformat(pattern = “yyyy-mm-dd hh:mm:ss”)

The @DateTimeFormat annotation allows you to specify the format of a date-time field when it is displayed or parsed. In your example, the pattern is specified as “yyyy-mm-dd hh:mm:ss”, which indicates that the date should be formatted as a string with the year, month, and day in the yyyy-mm-dd format and the hour, minute, and second in the hh:mm:ss format.

Here is an example of how you might use the @DateTimeFormat annotation with this pattern:

import org.springframework.format.annotation.DateTimeFormat;

public class Event {
    private String name;
    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private LocalDateTime date;

    // constructor, getters, and setters...
}

In this example, the Event class has a name field and a date field, which is annotated with the @DateTimeFormat annotation and the “yyyy-MM-dd HH:mm:ss” pattern. This specifies that the date field should be formatted as a date and time in the yyyy-MM-dd HH:mm:ss format when it is displayed or parsed.

You can use this annotation in combination with Spring’s @Controller and @RequestMapping annotations to specify the format of the date when it is received as a request parameter or when it is included in the model for a view.

For example, you might have a controller method like this:

@PostMapping("/events")
public String createEvent(@ModelAttribute @Valid Event event, BindingResult bindingResult, Model model) {
    if (bindingResult.hasErrors()) {
        return "form";
    }
    // save the event and redirect to the events list
    return "redirect:/events";
}

In this example, the createEvent method handles a POST request to the /events URL and creates a new Event object from the request parameters. The @DateTimeFormat annotation specifies that the date field should be parsed as a date and time in the yyyy-MM-dd HH:mm:ss format.

Spring Boot Date format validation annotation

In Spring Boot, you can use the @DateTimeFormat annotation to specify the format of a date-time field when it is displayed or parsed. For example:

import org.springframework.format.annotation.DateTimeFormat;

@Entity
public class Event {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;

    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private LocalDateTime date;

    // constructor, getters, and setters...
}

In this example, the Event class has a name field and a date field, which is annotated with the @DateTimeFormat annotation and the “yyyy-MM-dd HH:mm:ss” pattern. This specifies that the date field should be formatted as a date and time in the yyyy-MM-dd HH:mm:ss format when it is displayed or parsed.

You can use this annotation in combination with Spring Boot’s @Controller and @RequestMapping annotations to specify the format of the date when it is received as a request parameter or when it is included in the model for a view.

If you want to validate the format of the date, you can use the @Valid annotation and the BindingResult class to check for errors. For example:

@PostMapping("/events")
public String createEvent(@ModelAttribute @Valid Event event, BindingResult bindingResult, Model model) {
    if (bindingResult.hasErrors()) {
        return "form";
    }
    eventRepository.save(event);
    return "redirect:/events";
}

In this example, the createEvent method handles a POST request to the /events URL and creates a new Event object from the request parameters. The @Valid annotation triggers validation of the Event object, and the bindingResult object holds any validation errors. If there are any errors, the user is shown the form again. If the validation is successful, the eventRepository.save(event) method saves the Event object to the database, and the user is redirected to the /events URL.

Cannot deserialize value of type java util date from String

It sounds like you are trying to deserialize a JSON string that contains a date field into a Java object, and you are getting an error saying “Cannot deserialize value of type java.util.Date from String.” This error occurs when the JSON string contains a date in a format that cannot be parsed into a java.util.Date object.

To fix this error, you will need to make sure that the JSON string contains the date in a format that can be parsed into a java.util.Date object. You can use the @JsonFormat annotation to specify the format of the date when it is serialized and deserialized.

For example, if the JSON string contains the date in the yyyy-MM-dd’T’HH:mm:ss’Z’ format, you can use the following @JsonFormat annotation:

import com.fasterxml.jackson.annotation.JsonFormat;

public class MyClass {
    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss'Z'")
    private Date date;
    // other fields and methods...
}

You can also use the @JsonDeserialize and @JsonSerialize annotations to specify custom deserializers and serializers for the date field.

For example:

import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;

public class MyClass {
    @JsonDeserialize(using = CustomDateDeserializer.class)
    @JsonSerialize(using = CustomDateSerializer.class)
    private Date date;
    // other fields and methods...
}

In this example, the CustomDateDeserializer class is a custom deserializer that knows how to parse the date from the JSON string, and the CustomDateSerializer class is a custom serializer that knows how to format the date as a JSON string.

How to Integrate Data-dog with Spring example

Datadog is a cloud-based monitoring and analytics platform for modern cloud environments. It provides real-time visibility into the performance, health, and security of your infrastructure, applications, and logs. With Datadog, you can monitor your systems, track errors and exceptions, and get alerted when issues arise. You can also use the platform to investigate and troubleshoot problems, optimize your application performance, and ensure the security and compliance of your systems. Datadog integrates with a wide range of technologies and services, including cloud providers, databases, servers, containers, and more.

How to Integrate Data-dog with Spring example

To add tracing to a Spring application using Datadog, you will need to include the Datadog Java library in your application and use it to instrument your code. This will allow you to send trace data from your application to the Datadog Agent, which will then forward it to the Datadog APM (Application Performance Monitoring) platform.

Here’s a high-level overview of the steps you can follow to add tracing to a Spring application using Datadog:

1. Include the Datadog Java library in your application. You can do this using Maven by adding the following dependency to your pom.xml file:


  com.datadog
  dd-java-agent
  0.46.0

2. Instrument your code with Datadog tracing. The Datadog Java library provides a Tracer class that you can use to add trace spans to your code. A trace span represents a unit of work in your application, such as a database query or a remote service call. You can create a span using the Tracer.startSpan() method and specify a name for the span and any relevant tags. When the span is complete, you can stop it using the Tracer.finishSpan() method.

3. (Optional) Enable automatic instrumentation for common libraries and frameworks. The Datadog Java library includes automatic instrumentation for various libraries and frameworks, such as Spring, Hibernate, and JDBC. You can enable this instrumentation by adding the relevant dependencies to your application and including the necessary configuration in your application’s application.properties file.

4. Deploy your application and start sending trace data to Datadog. Once you have instrumented your code and enabled automatic instrumentation (if desired), you can deploy your application and start sending trace data to the Datadog Agent. The trace data will then be forwarded to the Datadog APM platform, where you can view and analyze it.

DataDog can Automatic Instrumentation with SpringBoot RestAPI

Yes, DataDog’s Java library includes automatic instrumentation for Spring Boot REST APIs. This means that you can use the library to automatically capture trace data for your REST API without having to manually instrument your code.

To enable automatic instrumentation for your Spring Boot REST API, you will need to include the Datadog Java library and the Spring Boot starter in your application, and configure the library to enable automatic instrumentation.

Here’s a high-level overview of the steps you can follow to enable automatic instrumentation for a Spring Boot REST API using DataDog:

1. Include the Datadog Java library and the Spring Boot starter in your application. You can do this using Maven by adding the following dependencies to your pom.xml file:


  com.datadog
  dd-java-agent
  0.46.0


  com.datadog.tracing
  dd-trace-spring-boot-starter
  0.46.0

2. Enable automatic instrumentation in your application’s configuration. You can enable automatic instrumentation by adding the following configuration to your application’s application.properties file:

dd.instrumentation.spring.web.enabled=true

Deploy your application and start capturing trace data. Once you have included the necessary dependencies and enabled automatic instrumentation, you can deploy your application and start capturing trace data for your REST API. The trace data will be sent to the Datadog Agent, which will forward it to the Datadog APM platform.

What is StatsDClient and how to use it?

StatsD is a network daemon that runs on your server and listens for statistics that are sent to it over UDP. It can then forward these statistics to a backend service such as Datadog, Graphite, or InfluxDB for storage and visualization.

The StatsDClient is a Java library that provides a client implementation of the StatsD protocol. You can use the StatsDClient to send custom metrics from your Java application to a StatsD daemon running on your server. The StatsDClient provides a simple interface for sending various types of metrics, such as counters, gauges, and histograms.

Here’s a simple example of how to use the StatsDClient to send a counter metric to a StatsD daemon:

import com.timgroup.statsd.StatsDClient;

// Create a StatsDClient
StatsDClient statsd = new NonBlockingStatsDClient("my_application", "localhost", 8125);

// Increment a counter metric
statsd.incrementCounter("page_views");

// Close the StatsDClient
statsd.stop();

This code creates a new StatsDClient that connects to a StatsD daemon running on localhost at port 8125. It then increments a counter metric called “page_views” and sends it to the daemon. Finally, it closes the StatsDClient.

Lombok Java Example

Project Lombok is a Java library that can be used to reduce boilerplate code in Java programs. Here is an example of how Lombok can be used to generate getters, setters, and a constructor for a Java class:

import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
public class User {
  private String name;
  private int age;
}

With Lombok, the @Data annotation will generate getters and setters for the name and age fields, as well as an equals, hashCode, and toString method. The @NoArgsConstructor annotation will generate a no-arguments constructor.

Without Lombok, the equivalent code would be:

public class User {
  private String name;
  private int age;
  
  public User() {}
  
  public String getName() {
    return name;
  }
  
  public void setName(String name) {
    this.name = name;
  }
  
  public int getAge() {
    return age;
  }
  
  public void setAge(int age) {
    this.age = age;
  }
  
  @Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;
    User user = (User) o;
    return age == user.age &&
        Objects.equals(name, user.name);
  }
  
  @Override
  public int hashCode() {
    return Objects.hash(name, age);

Having any problem with performance when using Lombok in Java project

Using Project Lombok in a Java project should not have any negative impact on performance. Lombok is designed to reduce boilerplate code, which can improve readability and maintainability of the codebase, but it does not add any additional runtime overhead.

Lombok works by generating code at compile time, so the generated code is included in the compiled class files and executed at runtime just like any other code. The code generation process is transparent to the developer and should not affect the performance of the application.

However, it is always a good idea to measure the performance of your application and ensure that it meets your requirements. If you are concerned about the performance of your application and want to optimize it, you should consider profiling the application and identifying any bottlenecks or areas that could be optimized.

Example Lombok with Spring Data JPA

Here is an example of how Project Lombok can be used in combination with Spring Data JPA to reduce boilerplate code in a Java application:

import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Data
@NoArgsConstructor
@Entity
public class User {
  @Id
  @GeneratedValue
  private Long id;
  private String name;
  private int age;
}

In this example, the @Data annotation generates getters and setters for the id, name, and age fields, as well as an equals, hashCode, and toString method. The @NoArgsConstructor annotation generates a no-arguments constructor. The @Entity annotation indicates that this class is a JPA entity, and the @Id and @GeneratedValue annotations are used to specify the primary key and generate a unique identifier for each user.

With these annotations, you can avoid having to write the boilerplate code for getters, setters, and a constructor, as well as the JPA annotations for the primary key and identifier generation. This can make your code more concise and easier to read and maintain.

To use Lombok with Spring Data JPA, you will need to include the Lombok library in your project and configure your build tool to process the Lombok annotations. You will also need to configure your JPA persistence provider and set up a database to store the entity data.

Example Lombok with SpringBoot Rest API

Here is an example of how Project Lombok can be used in combination with Spring Boot to create a simple REST API:

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {

  @GetMapping("/users/{id}")
  public User getUser(@PathVariable Long id) {
    return new User(id, "John", 30);
  }

}

@Data
@NoArgsConstructor
@AllArgsConstructor
class User {
  private Long id;
  private String name;
  private int age;
}

In this example, the @RestController annotation indicates that the UserController class is a Spring MVC controller that handles HTTP requests. The @GetMapping annotation specifies that the getUser method should handle GET requests to the /users/{id} endpoint. The @PathVariable annotation is used to bind the value of the id path variable to the id parameter of the getUser method.

The User class is annotated with @Data, @NoArgsConstructor, and @AllArgsConstructor, which generate getters and setters for the id, name, and age fields, as well as an equals, hashCode, and toString method, and a no-arguments and all-arguments constructor.

With these annotations, you can avoid having to write the boilerplate code for the controller and the user class, making your code more concise and easier to read and maintain.

To use Lombok with Spring Boot, you will need to include the Lombok library in your project and configure your build tool to process the Lombok annotations. You will also need to set up a Spring Boot application and configure the application to serve the REST API.

How about Java community statistics using Lombok

It is difficult to provide accurate statistics on the usage of Project Lombok within the Java community. However, Lombok has been widely adopted by Java developers and is considered a popular library for reducing boilerplate code in Java projects.

According to the Project Lombok website, Lombok has been downloaded over 50 million times and is used by millions of developers around the world. In addition, Lombok has received widespread recognition and has been featured in various publications and conference talks.

Many Java developers find Lombok to be a useful tool for reducing boilerplate code and improving the readability and maintainability of their codebase. However, as with any library, Lombok is not suitable for every project and it is up to each developer to decide whether it is a good fit for their needs.