Foo.java

import java.io.Serializable;
import org.codehaus.jackson.annotate.JsonProperty;

public class Foo implements Serializable {

  private static final long serialVersionUID = 1L;

  @JsonProperty("id")
  private Long id;

  @JsonProperty("n")
  private String name;

  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;
  }
}

ReadListFromJsonReponse.java

public List<Foo> list(Long id) throws Exception {
  HttpResponse response = client.execute(post(url, params("foo_id", id)));
  return mapper.readValue(
    response.getEntity().getContent(), 
    TypeFactory.collectionType(List.class, Foo.class)
  );
}