Listar dados de Cliente a partir de seleção no selectOneMenu

///
#{atendimentoController.selected.atdOuvinte}

<h:selectOneMenu value="#{atendimentoController.selected.atdOuvinte}" class="form-control select2" style="width: 100%;">
   <f:selectItem itemLabel="-Selecione-" itemValue=""/>
   <f:selectItems value="#{ouvinteController.items}" var="item" itemValue="#{item.ouvintePK.ouvNome}" itemLabel="#{item.ouvintePK.ouvNome}" />
   <f:ajax listener="#{atendimentoController.metodoQueIraBuscarAsInformacoesQueVcDeseja}"/>
</h:selectOneMenu>

public class AtendimentoController
private Ouvinte ouvinteDetalhado;
// Aqui o atributo selected.atdOuvinte, me ajude o que seria este atributo selected? Class

public void buscarOuvinte(){
    Long idOuvinte = this.selected.atdOuvinte.getId();
    this.ouvinteDetalhado =   this.daoDoOuvinte.buscarOuvinteById(idOuvinte);
   //Apesar de achar isto redundante pois se você está passando o objeto pro selectOneMenu já tem as informaçoes carregadas..... 
}

import java.io.Serializable;

import java.util.Date;

import java.util.ResourceBundle;

import javax.ejb.EJB;

import javax.inject.Named;

import javax.enterprise.context.SessionScoped;

import javax.faces.component.UIComponent;

import javax.faces.context.FacesContext;

import javax.faces.convert.Converter;

import javax.faces.convert.FacesConverter;

import javax.faces.model.DataModel;

import javax.faces.model.ListDataModel;

import javax.faces.model.SelectItem;

import static pacote_jangadeiro.Ouvinte_.ouvDataregistro;

<a class="mention" href="/u/named">@Named</a>(“atendimentoController”)

@SessionScoped

public class AtendimentoController implements Serializable {

private Atendimento current;
private DataModel items = null;
@EJB
private pacote_jangadeiro.AtendimentoFacade ejbFacade;
private PaginationHelper pagination;
private int selectedItemIndex;

public AtendimentoController() {
}

public Atendimento getSelected() {
    if (current == null) {
        current = new Atendimento();
        selectedItemIndex = -1;
    }
    return current;
}

private Ouvinte ouvinteDetalhado;

public void Solucao() {
    System.out.println("kkkkkkk");
}

private AtendimentoFacade getFacade() {
    return ejbFacade;
}

public PaginationHelper getPagination() {
    if (pagination == null) {
        pagination = new PaginationHelper(10) {

            @Override
            public int getItemsCount() {
                return getFacade().count();
            }

            @Override
            public DataModel createPageDataModel() {
                return new ListDataModel(getFacade().findRange(new int[]{getPageFirstItem(), getPageFirstItem() + getPageSize()}));
            }
        };
    }
    return pagination;
}

public String prepareList() {
    recreateModel();
    return "List";
}

public String prepareView() {
    current = (Atendimento) getItems().getRowData();
    selectedItemIndex = pagination.getPageFirstItem() + getItems().getRowIndex();
    return "View";
}

public String prepareCreate() {
    current = new Atendimento();
    selectedItemIndex = -1;
    return "Create";
}

public String create() {
    try {
        getFacade().create(current);
        JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("AtendimentoCreated"));
        return prepareCreate();
    } catch (Exception e) {
        JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));
        return null;
    }
}

public String prepareEdit() {
    current = (Atendimento) getItems().getRowData();
    selectedItemIndex = pagination.getPageFirstItem() + getItems().getRowIndex();
    return "Edit";
}

public String update() {
    try {
        getFacade().edit(current);
        JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("AtendimentoUpdated"));
        return "View";
    } catch (Exception e) {
        JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));
        return null;
    }
}

public String destroy() {
    current = (Atendimento) getItems().getRowData();
    selectedItemIndex = pagination.getPageFirstItem() + getItems().getRowIndex();
    performDestroy();
    recreatePagination();
    recreateModel();
    return "List";
}

public String destroyAndView() {
    performDestroy();
    recreateModel();
    updateCurrentItem();
    if (selectedItemIndex >= 0) {
        return "View";
    } else {
        // all items were removed - go back to list
        recreateModel();
        return "List";
    }
}

private void performDestroy() {
    try {
        getFacade().remove(current);
        JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("AtendimentoDeleted"));
    } catch (Exception e) {
        JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));
    }
}

private void updateCurrentItem() {
    int count = getFacade().count();
    if (selectedItemIndex >= count) {
        // selected index cannot be bigger than number of items:
        selectedItemIndex = count - 1;
        // go to previous page if last page disappeared:
        if (pagination.getPageFirstItem() >= count) {
            pagination.previousPage();
        }
    }
    if (selectedItemIndex >= 0) {
        current = getFacade().findRange(new int[]{selectedItemIndex, selectedItemIndex + 1}).get(0);
    }
}

public DataModel getItems() {
    if (items == null) {
        items = getPagination().createPageDataModel();
    }
    return items;
}

private void recreateModel() {
    items = null;
}

private void recreatePagination() {
    pagination = null;
}

public String next() {
    getPagination().nextPage();
    recreateModel();
    return "List";
}

public String previous() {
    getPagination().previousPage();
    recreateModel();
    return "List";
}

public SelectItem[] getItemsAvailableSelectMany() {
    return JsfUtil.getSelectItems(ejbFacade.findAll(), false);
}

public SelectItem[] getItemsAvailableSelectOne() {
    return JsfUtil.getSelectItems(ejbFacade.findAll(), true);
}

public Atendimento getAtendimento(java.lang.Integer id) {
    return ejbFacade.find(id);
}

@FacesConverter(forClass = Atendimento.class)
public static class AtendimentoControllerConverter implements Converter {

    @Override
    public Object getAsObject(FacesContext facesContext, UIComponent component, String value) {
        if (value == null || value.length() == 0) {
            return null;
        }
        AtendimentoController controller = (AtendimentoController) facesContext.getApplication().getELResolver().
                getValue(facesContext.getELContext(), null, "atendimentoController");
        return controller.getAtendimento(getKey(value));
    }

    java.lang.Integer getKey(String value) {
        java.lang.Integer key;
        key = Integer.valueOf(value);
        return key;
    }

    String getStringKey(java.lang.Integer value) {
        StringBuilder sb = new StringBuilder();
        sb.append(value);
        return sb.toString();
    }

    @Override
    public String getAsString(FacesContext facesContext, UIComponent component, Object object) {
        if (object == null) {
            return null;
        }
        if (object instanceof Atendimento) {
            Atendimento o = (Atendimento) object;
            return getStringKey(o.getAtdId());
        } else {
            throw new IllegalArgumentException("object " + object + " is of type " + object.getClass().getName() + "; expected type: " + Atendimento.class.getName());
        }
    }

}