How to response with JSP file using JAX-RS?

I’ve just started learning Java. I’m trying to create a simple CRUD web application using JAX-RS. I’d like to have a few pages with forms that will be sending data to my API resources. Unfortunately, I don’t understand how I can render an html page using JAX-RS. Perhaps there is another way to do that?

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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.ev</groupId>
  <artifactId>jaxrsbasic</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>jaxrsbasic</name>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.glassfish.jersey.containers</groupId>
      <artifactId>jersey-container-servlet</artifactId>
      <version>2.31</version>
    </dependency>

    <dependency>
      <groupId>org.glassfish.jersey.core</groupId>
      <artifactId>jersey-server</artifactId>
      <version>2.31</version>
      <exclusions>
        <exclusion>
          <artifactId>jakarta.activation-api</artifactId>
          <groupId>jakarta.activation</groupId>
        </exclusion>
      </exclusions>
    </dependency>

    <dependency>
      <groupId>org.glassfish.jersey.inject</groupId>
      <artifactId>jersey-hk2</artifactId>
      <version>2.31</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish.jersey.media</groupId>
      <artifactId>jersey-media-json-jackson</artifactId>
      <version>2.31</version>
      <exclusions>
        <exclusion>
          <groupId>jakarta.activation</groupId>
          <artifactId>jakarta.activation-api</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.18.22</version>
    </dependency>
    <dependency>
      <groupId>com.github.javafaker</groupId>
      <artifactId>javafaker</artifactId>
      <version>1.0.2</version>
    </dependency>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.28</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
    <dependency>
      <groupId>org.postgresql</groupId>
      <artifactId>postgresql</artifactId>
      <version>42.3.2</version>
    </dependency>
      <dependency>
          <groupId>jakarta.servlet</groupId>
          <artifactId>jakarta.servlet-api</artifactId>
          <version>5.0.0</version>
      </dependency>

  </dependencies>

  <build>
    <finalName>jaxrsbasic</finalName>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.8.0</version>
        <configuration>
          <source>${maven.compiler.source}</source>
          <target>${maven.compiler.target}</target>
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-maven-plugin</artifactId>
        <version>9.4.29.v20200521</version>
      </plugin>
    </plugins>
  </build>
</project>

web.xml

<!DOCTYPE web-app PUBLIC
        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
        "http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
    <servlet>
        <servlet-name>REST Service Basic</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.ev.resources</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>REST Service Basic</servlet-name>
        <url-pattern>/api/*</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>REST Service Basic</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>
</web-app>

UserResource.java

package org.ev.resources;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.core.Response;

@Path("/users")
public class UserResource {
    @GET
    @Path("/list")
    public Response list() {
        return Response.ok().entity("Hello World!").build();
    }
}

Answer

I think you are confused with different technologies. If you want to render HTML page then you should use either Servlet JSP or other rendering mechanism, for example, Thymeleaf. JAX-RS is used for REST.

For example, you can render your HTML page on server using JSP/Thymeleaf, when page is loaded in browser, JavaScript will make a REST call to JAX-RS and after getting answer from REST resource it (js) will add data to HTML page.

A full JSP example is here. A full example Spring Boot + Thymeleaf is here. I would suggest to use Thymeleaf.

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Answer