Rest API simple Application with http mothods

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We will be developing REST API using JAX-RS (Jersey) and Tomcat server and we will be implementing basic 4 methods so lets get started

Here is pom.xml file:

<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 http://maven.apache.org/maven-v4_0_0.xsd"><modelVersion>4.0.0</modelVersion><groupId>org.dpq.webservices</groupId><artifactId>SimpleRestApiApp</artifactId><packaging>war</packaging><version>0.0.1-SNAPSHOT</version><name>SimpleRestApiApp</name><build>        <finalName>SimpleRestApiApp</finalName>        <plugins>                 <plugin>                         <groupId>org.apache.maven.plugins</groupId>                         <artifactId>maven-compiler-plugin</artifactId>                         <version>3.8.1</version>                         <inherited>true</inherited>                         <configuration>                                        <source>1.8</source>                                        <target>1.8</target>                         </configuration>                </plugin>        </plugins></build><dependencyManagement>                      <dependencies>                                    <dependency>                                                <groupId>org.glassfish.jersey</groupId>                                                <artifactId>jersey-bom</artifactId>                                                <version>${jersey.version}</version>                                                <type>pom</type>                                                <scope>import</scope>                                    </dependency>                      </dependencies></dependencyManagement><dependencies><dependency><groupId>org.glassfish.jersey.media</groupId><artifactId>jersey-media-json-jackson</artifactId><version>${jersey.version}</version></dependency> <dependency><groupId>jakarta.xml.bind</groupId><artifactId>jakarta.xml.bind-api</artifactId><version>3.0.0</version></dependency><dependency><groupId>com.sun.xml.bind</groupId><artifactId>jaxb-impl</artifactId><version>3.0.0</version><scope>runtime</scope></dependency><dependency><groupId>org.glassfish.jersey.media</groupId><artifactId>jersey-media-jaxb</artifactId><version>3.0.2</version></dependency><dependency><groupId>org.glassfish.jersey.containers</groupId><artifactId>jersey-container-servlet-core</artifactId></dependency><dependency><groupId>org.glassfish.jersey.inject</groupId><artifactId>jersey-hk2</artifactId></dependency><dependency><groupId>javax.xml.bind</groupId><artifactId>jaxb-api</artifactId><version>2.3.0</version></dependency>             </dependencies><properties><jersey.version>3.0.3</jersey.version><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties></project>

src/main/webapp/WEB-INF/web.xml

Here Jersey ServletContainer will serve request with using specified url-pattern and will lookup resources to be serves inside mentioned package

<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"><servlet><servlet-name>Jersey Web Application</servlet-name><servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class><init-param><param-name>jersey.config.server.provider.packages</param-name><param-value>org.dpq.webservices.resources</param-value></init-param><load-on-startup>1</load-on-startup></servlet><servlet-mapping><servlet-name>Jersey Web Application</servlet-name><url-pattern>/*</url-pattern></servlet-mapping></web-app>

src/main/java/org/dpq/webservices/resources/MyResource.java

package org.dpq.webservices.resources;import java.util.Arrays;import java.util.HashMap;import java.util.Map;import jakarta.inject.Singleton;import jakarta.ws.rs.Consumes;import jakarta.ws.rs.DELETE;import jakarta.ws.rs.GET;import jakarta.ws.rs.Path;import jakarta.ws.rs.PathParam;import jakarta.ws.rs.Produces;import jakarta.ws.rs.core.MediaType;@Path("/msgs")@Produces({MediaType.APPLICATION_JSON , MediaType.TEXT_PLAIN})@Consumes(MediaType.APPLICATION_JSON)@Singletonpublic class MyResource {  private Map<Long,String> messages = new HashMap<>();  public MyResource() {    System.out.println("Instance created...");    messages.put(1L,"I am fine");    messages.put(2L,"How are you");    messages.put(3L,"Hope you are doing well");  }  @GET  @Path("/{messageId}")  @Produces(MediaType.TEXT_PLAIN)  public String getMessage(@PathParam("messageId") long id) {    return messages.get(id);  }     @DELETE  @Path("/{messageId}")  public void deleteMessage(@PathParam("messageId") long id) {    messages.remove(id);    System.out.println("messages:: "+messages);  }  @GET  @Path("/all")  @Produces(MediaType.TEXT_PLAIN)  public String getAllMessages() {    return Arrays.toString(messages.values().stream().toArray(String [] :: new));  }  @GET  @Path("/dummy")  @Produces(MediaType.TEXT_PLAIN)  public String getText() {     return "Dummy message";  }}
Please follow my below Git hub for this repo

https://github.com/Deepak-Bhardwaj-Architect/SimpleRestApiApp

https://github.com/Deepak-Bhardwaj-Architect/SimpleRestApiApp

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