Why Json test program doesn't work?

Question

When I run a Json test program with jdk 7, it says :

Exception in thread "main" javax.json.JsonException: Provider org.glassfish.json.JsonProviderImpl not found
    at javax.json.spi.JsonProvider.provider(JsonProvider.java:97)
    at javax.json.Json.createArrayBuilder(Json.java:257)"

I've included "javax.json-api-1.0.jar" in my project.

import javax.json.Json;
import javax.json.JsonArray;
import javax.json.JsonArrayBuilder;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class JsonExample
{
  public static void main(String[] args)
  {
    List<User> users=getUsers();

    // build JSON
    JsonArrayBuilder jsonArrayBuilder=Json.createArrayBuilder();
    for (User user : users)
    {
      jsonArrayBuilder.add(
        Json.createObjectBuilder()
        .add("id",user.getId())
        .add("name",user.getName())
        .add("join",user.getJoin().getTime()));
    }

    JsonArray usersJson=jsonArrayBuilder.build();

    System.out.println(usersJson.toString());

  }

  // dummy users
  public static List<User> getUsers()
  {
    List<User> users=new ArrayList<User>(10);
    User user=new User();
    user.setId(1);
    user.setName("Hero");
    user.setJoin(new Date());
    users.add(user);

    user=new User();
    user.setId(2);
    user.setName("Citizen");
    user.setJoin(new Date());
    users.add(user);

    return users;
  }

  // POJO
  public static class User implements Serializable
  {
    private long id;
    private String name;
    private Date join;

    public long getId()
    {
      return id;
    }

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

    public String getName()
    {
      return name;
    }

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

    public Date getJoin()
    {
      return join;
    }

    public void setJoin(Date join)
    {
      this.join=join;
    }
  }
}

It's a simple program, not using galssfish, why is glassfish mentioned here ?

Answer 1

javax.json-api-1.0.jar contains only API which is there for compile time dependency. But if you want to run your app, you need a provider / impl classes.

org.glassfish:javax.json is the jar you need that contains both api + impl classes.

<dependency>
    <groupId>org.glassfish</groupId>
    <artifactId>javax.json</artifactId>
    <version>1.0.4</version>
</dependency>

See this thread for more details.