(Slightly tweaked) code from watching Hello JavaEE 7 With Maven 3, JAX-RS 2.0 and JSON ...In 3 Mins : Adam Bien's Weblog - http://www.adam-bien.com/roller/abien/entry/hello_javaee_7_with_maven

1st-readme.md

For {"hello":"world"} from http://localhost:8080/json/resources/greetings

http://www.adam-bien.com/roller/abien/entry/hello_javaee_7_with_maven

https://github.com/AdamBien/javaee7-essentials-archetype

http://search.maven.org/#search|ga|1|a%3A%22javaee7-essentials-archetype%22

GreetingsResource.java

package com.greptilian.json;

import javax.json.Json;
import javax.json.JsonObject;
import javax.ws.rs.GET;
import javax.ws.rs.Path;

@Path("greetings")
public class GreetingsResource {

    @GET
    public JsonObject greetings() {
        return Json.createObjectBuilder().add("hello", "world").build();
    }
}

pom.xml

<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>com.greptilian</groupId>
    <artifactId>json</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>
    <dependencies>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>7.0</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    <properties>
        <maven.compiler.source>1.7</maven.compiler.source>
        <maven.compiler.target>1.7</maven.compiler.target>
        <failOnMissingWebXml>false</failOnMissingWebXml>
    </properties>
</project>

RESTConfiguration.java

package com.greptilian.json;

import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;

@ApplicationPath("resources")
public class RESTConfiguration extends Application {
}