rizvifazi/EmployeeinfoSpring

Spring based REST API to Manage Employee Data

EmployeeInfoSpring

Spring based REST API application to manage Employee details.

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Usage

1. Clone the repo
2. Open via IDE (Eclipse) and Import as Existing Maven Project
3. Show in Local terminal and run mvn clean install
4. Update the project to import all dependencies

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System requirements

1. JDK 17 or above

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Implementation

1. Download Spring Initializr

• Download Spring Initializr with Spring Web and Spring Dev Tools Dependencies from https://start.spring.io

2. Follow the basic 6 steps

• mvn clean install and Update the project

3.pom.xml

• No any configurations to be done in pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>3.2.6</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.pack</groupId>
	<artifactId>Employeeinfosb</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>Employeeinfosb</name>
	<description>Display employee info in JSON format</description>
	<properties>
		<java.version>17</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<scope>runtime</scope>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>
	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

4. Configure Application Properties

• Setting logging level, port and context-path for best practice.
• application.propertiesfile will be inside /src/main/resources directory

spring.application.name=EmployeeinfoSpring
logging.level.web=DEBUG
server.port=8080
server.servlet.context-path=/app

5. Create EmployeeInfo.class

package com.pack.EmployeeinfoSpring.service;

//No annotations required here @Entity can be used if we are using JPA
public class EmployeeInfo {

	private Integer id;
	private String name;
	private Double salary;
	private String address;

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public Double getSalary() {
		return salary;
	}

	public void setSalary(Double salary) {
		this.salary = salary;
	}

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	public EmployeeInfo() {
	}

	public EmployeeInfo(String name) {
		this.name = name;
	}

	public EmployeeInfo(Integer id, String name, Double salary, String address) {
		super();
		this.id = id;
		this.name = name;
		this.salary = salary;
		this.address = address;
	}

	@Override
	public String toString() {
		return "EmployeeInfo [id=" + id + ", name=" + name + ", salary=" + salary + ", address=" + address + "]";
	}

}

6. Create EmployeeDaoService.class

• This @Component class will be used to preload dummy employees in the employee list, return list of employees as well as to return an individual employee details based on the @Pathvariable in the GetRequest URL.

package com.pack.EmployeeinfoSpring.service;

import java.util.ArrayList;
import java.util.List;
import org.springframework.stereotype.Component;

@Component
public class EmployeeDaoService {

	private static List<EmployeeInfo> employees = new ArrayList<>();

	// Static block to pre-load dummy employees
	static {
		employees.add(new EmployeeInfo(1, "Alice Johnson", 52000.00, "San Francisco, CA"));
		employees.add(new EmployeeInfo(2, "Bob Williams", 48000.00, "Seattle, WA"));
		employees.add(new EmployeeInfo(3, "Charlie Miller", 61000.00, "New York, NY"));
		employees.add(new EmployeeInfo(4, "Diana Garcia", 39000.00, "Austin, TX"));
		employees.add(new EmployeeInfo(5, "Ethan Lee", 45000.00, "Chicago, IL"));
	}

	// returns list of employees
	public List<EmployeeInfo> findAll() {
		return employees;
	}

	//to return employee details based on @Pathvariable String
	public EmployeeInfo findOne(int id) {

		for (EmployeeInfo e : employees) {
			if (e.getId() == id)
				return e;
		}
		return null;
	}

}

7. Create EmployeeController.class

• This is the @RestController class which imlements the ErrorController FI and defines the Request mappings.

package com.pack.EmployeeinfoSpring.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.servlet.error.ErrorController;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import com.pack.EmployeeinfoSpring.service.EmployeeDaoService;
import com.pack.EmployeeinfoSpring.service.EmployeeInfo;

@RestController
public class EmployeeController implements ErrorController {

	// Defining for Error page
	protected static final String PATH = "/error";

	// Return a HTML based string to print useful information if entered a incorrect
	// URL
	@GetMapping(value = PATH)
	public String getErrorMessage() {
		return """
						<h2 style="font-weight: bold; color: red; margin: 2rem 0;">Error 404! Please check the URL</h2>
							<p>The requested resource was not found.</p>
						<h3 style="font-family: monospace; font-size: smaller; margin-top: 1rem;">Correct Usage:</h3>
						  <ul>
						    <li style="font-family: monospace;">localhost:2020/app/employees</li>
						    <li style="font-family: monospace;">localhost:2020/app/employee/{id}</li>
						  </ul>
				""";
	}

	// This needs to be implemented for ErrorController functional interface
	public String getErrorPath() {
		return PATH;
	}

	// Referring another (DAO) component here
	@Autowired
	private EmployeeDaoService service;

	// Get Request Mapping to list all employees
	@GetMapping(value = "/employees")
	public List<EmployeeInfo> getAllEmployees() {
		return service.findAll();
	}

	// Get Request Mapping and retrieve individual employee data
	@GetMapping(value = "/employee/{id}")
	public EmployeeInfo getEmployeeInfo(@PathVariable Integer id) {
		return service.findOne(id);
	}

}

8. EmployeeInfoSpringApplication.class

• Run the program as Java Application from EmployeeInfoSpringApplication.class

package com.pack.EmployeeinfoSpring;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class EmployeeinfoSpringApplication {

	public static void main(String[] args) {
		SpringApplication.run(EmployeeinfoSpringApplication.class, args);
	}

}

9. Console Output

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v3.2.6)

2024-06-09T23:24:58.504+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] c.p.E.EmployeeinfoSpringApplication      : Starting EmployeeinfoSpringApplication using Java 17.0.7 with PID 6228 (C:\Users\acer\eclipse-workspace\EmployeeinfoSpring\target\classes started by acer in C:\Users\acer\eclipse-workspace\EmployeeinfoSpring)
2024-06-09T23:24:58.506+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] c.p.E.EmployeeinfoSpringApplication      : No active profile set, falling back to 1 default profile: "default"
2024-06-09T23:24:58.550+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
2024-06-09T23:24:59.376+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port 8080 (http)
2024-06-09T23:24:59.389+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2024-06-09T23:24:59.390+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] o.apache.catalina.core.StandardEngine    : Starting Servlet engine: [Apache Tomcat/10.1.24]
2024-06-09T23:24:59.434+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/app]    : Initializing Spring embedded WebApplicationContext
2024-06-09T23:24:59.436+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 885 ms
2024-06-09T23:24:59.450+05:30 DEBUG 6228 --- [EmployeeinfoSpring] [  restartedMain] o.s.b.w.s.ServletContextInitializerBeans : Mapping filters: characterEncodingFilter urls=[/*] order=-2147483648, formContentFilter urls=[/*] order=-9900, requestContextFilter urls=[/*] order=-105
2024-06-09T23:24:59.451+05:30 DEBUG 6228 --- [EmployeeinfoSpring] [  restartedMain] o.s.b.w.s.ServletContextInitializerBeans : Mapping servlets: dispatcherServlet urls=[/]
2024-06-09T23:24:59.592+05:30 DEBUG 6228 --- [EmployeeinfoSpring] [  restartedMain] s.w.s.m.m.a.RequestMappingHandlerMapping : 3 mappings in 'requestMappingHandlerMapping'
2024-06-09T23:24:59.638+05:30 DEBUG 6228 --- [EmployeeinfoSpring] [  restartedMain] o.s.w.s.handler.SimpleUrlHandlerMapping  : Patterns [/webjars/**, /**] in 'resourceHandlerMapping'
2024-06-09T23:24:59.658+05:30 DEBUG 6228 --- [EmployeeinfoSpring] [  restartedMain] s.w.s.m.m.a.RequestMappingHandlerAdapter : ControllerAdvice beans: 0 @ModelAttribute, 0 @InitBinder, 1 RequestBodyAdvice, 1 ResponseBodyAdvice
2024-06-09T23:24:59.685+05:30 DEBUG 6228 --- [EmployeeinfoSpring] [  restartedMain] .m.m.a.ExceptionHandlerExceptionResolver : ControllerAdvice beans: 0 @ExceptionHandler, 1 ResponseBodyAdvice
2024-06-09T23:24:59.730+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] o.s.b.d.a.OptionalLiveReloadServer       : LiveReload server is running on port 35729
2024-06-09T23:24:59.763+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port 8080 (http) with context path '/app'
2024-06-09T23:24:59.772+05:30  INFO 6228 --- [EmployeeinfoSpring] [  restartedMain] c.p.E.EmployeeinfoSpringApplication      : Started EmployeeinfoSpringApplication in 1.558 seconds (process running for 1.848)

Navigate to http://localhost:8080/app/employees through a browser to See the browser output in JSON format.

10. Browser Outputs

http://localhost:8080/app/employees

[
  {
    "id": 1,
    "name": "Alice Johnson",
    "salary": 52000,
    "address": "San Francisco, CA"
  },
  {
    "id": 2,
    "name": "Bob Williams",
    "salary": 48000,
    "address": "Seattle, WA"
  },
  {
    "id": 3,
    "name": "Charlie Miller",
    "salary": 61000,
    "address": "New York, NY"
  },
  {
    "id": 4,
    "name": "Diana Garcia",
    "salary": 39000,
    "address": "Austin, TX"
  },
  {
    "id": 5,
    "name": "Ethan Lee",
    "salary": 45000,
    "address": "Chicago, IL"
  }
]

http://localhost:8080/app/employee/3

{
  "id": 3,
  "name": "Charlie Miller",
  "salary": 61000,
  "address": "New York, NY"
}

Error Page

<h2 style="font-weight: bold; color: red; margin: 2rem 0;">Error 404! Please check the URL</h2>
	<p>The requested resource was not found.</p>
<h3 style="font-family: monospace; font-size: smaller; margin-top: 1rem;">Correct Usage:</h3>
  <ul>
	<li style="font-family: monospace;">localhost:2020/app/employees</li>
	<li style="font-family: monospace;">localhost:2020/app/employee/{id}</li>
  </ul>