Webservice com Jersey

Falae, Momad! Tudo bem? Cara, inicia seu projeto como Maven Project. Vai no pom.xml e adiciona as dependências lá. Pra você saber certinho como colocar no pom, é só buscar lá no repositório do maven.

http://mvnrepository.com/

Lá tem um campo de busca. Você digita a dependência que quer, clica na versão desejada e escolhe "Maven" na aba. Ele já vai te dar as tags certinhas pra você copiar e colcar no seu pom.xml, dentro da tag .

Espero ter ajudado! Abraços! ;)

Eu adicionei as seguintes dependências no pom.xml para os que ainda estão com problemas.

<!-- https://mvnrepository.com/artifact/javax.ws.rs/javax.ws.rs-api -->
        <dependency>
            <groupId>javax.ws.rs</groupId>
            <artifactId>javax.ws.rs-api</artifactId>
            <version>2.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.7</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/xstream/xstream -->
        <dependency>
            <groupId>xstream</groupId>
            <artifactId>xstream</artifactId>
            <version>1.2.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.glassfish.grizzly/grizzly-http-server -->
        <dependency>
            <groupId>org.glassfish.grizzly</groupId>
            <artifactId>grizzly-http-server</artifactId>
            <version>2.3.26</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.containers/jersey-container-grizzly2-http -->
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-grizzly2-http</artifactId>
            <version>2.4</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.core/jersey-server -->
        <dependency>
            <groupId>org.glassfish.jersey.core</groupId>
            <artifactId>jersey-server</artifactId>
            <version>2.5.1</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.core/jersey-common -->
        <dependency>
            <groupId>org.glassfish.jersey.core</groupId>
            <artifactId>jersey-common</artifactId>
            <version>2.5.1</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.core/jersey-client -->
        <dependency>
            <groupId>org.glassfish.jersey.core</groupId>
            <artifactId>jersey-client</artifactId>
            <version>2.5.1</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.containers/jersey-container-servlet -->
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet</artifactId>
            <version>2.5.1</version>
        </dependency>

muito tempo depois, essas dependências resolveram pra mim

<dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.0</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-grizzly2-http</artifactId>
            <version>2.25.1</version>
        </dependency>