Arquivo Discussoes de Programacao e Tecnologia 
Fiz uma view assim:
<s:decorate id=“conhecimentoPessoaDecoration” template=“layout/edit.xhtml”>
<ui:define name=“label”>Conhecimentos:</ui:define>
<h:selectManyCheckbox value="#{pessoaHome.instance.conhecimentos}" converter="#{conhecimentoConverter}">
<f:selectItems value="#{conhecimentoBean.selectItems}"/>
</h:selectManyCheckbox>
</s:decorate>
meu ConhecimentoBean
package org.domain.testerelacionamento.beans;
import java.util.ArrayList;
import java.util.List;
import javax.faces.model.SelectItem;
import org.domain.testerelacionamento.business.SeamConhecimentoList;
import org.domain.testerelacionamento.entity.Conhecimento;
import org.jboss.seam.ScopeType;
import org.jboss.seam.annotations.AutoCreate;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Out;
import org.jboss.seam.annotations.Scope;
@AutoCreate
@Name(“conhecimentoBean”)
@Scope(ScopeType.SESSION)
public class ConhecimentoBean {
@In
private SeamConhecimentoList conhecimentoList;
@Out
private List<SelectItem> selectItems;
{
preencheItems();
}
private Conhecimento conhecimento;
@SuppressWarnings("unchecked")
private void preencheItems() {
selectItems = new ArrayList<SelectItem>();
for(Conhecimento conhecimento: conhecimentoList.getResultList()){
selectItems.add(new SelectItem(conhecimento,conhecimento.getConhecimento()));
}
}
public List<SelectItem> getSelectItems() {
return selectItems;
}
public void setSelectItems(List<SelectItem> selectItems) {
this.selectItems = selectItems;
}
public Conhecimento getConhecimento() {
return conhecimento;
}
public void setConhecimento(Conhecimento conhecimento) {
this.conhecimento = conhecimento;
}
}
o meu converter
package org.domain.testerelacionamento.util.converters;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
import org.domain.testerelacionamento.business.SeamConhecimentoList;
import org.jboss.seam.ScopeType;
import org.jboss.seam.annotations.AutoCreate;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Scope;
@AutoCreate
@Name(“conhecimentoConverter”)
@Scope(ScopeType.SESSION)
public class ConhecimentoConverter implements Converter {
@In
private SeamConhecimentoList conhecimentoList;
public Object getAsObject(FacesContext context, UIComponent component, String value) {
return conhecimentoList.findByName(value);
}
public String getAsString(FacesContext context, UIComponent component, Object object) {
return object.toString();
}
}
ai recebo a seguinte exceção
org.jboss.seam.InstantiationException: Could not instantiate Seam component: conhecimentoBean
at org.jboss.seam.Component.newInstance(Component.java:2144)
at org.jboss.seam.Component.getInstance(Component.java:2021)
at org.jboss.seam.Component.getInstance(Component.java:1983)
at org.jboss.seam.Component.getInstance(Component.java:1977)
at org.jboss.seam.Namespace.getComponentInstance(Namespace.java:55)
at org.jboss.seam.Namespace.getComponentInstance(Namespace.java:50)
at org.jboss.seam.el.SeamELResolver.resolveBase(SeamELResolver.java:147)
at org.jboss.seam.el.SeamELResolver.getValue(SeamELResolver.java:51)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54)
at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72)
at org.jboss.el.parser.AstIdentifier.getValue(AstIdentifier.java:44)
at org.jboss.el.parser.AstValue.getValue(AstValue.java:63)
at org.jboss.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
at com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:71)
at javax.faces.component.UISelectItems.getValue(UISelectItems.java:141)
at com.sun.faces.renderkit.RenderKitUtils.getSelectItems(RenderKitUtils.java:289)
at com.sun.faces.renderkit.html_basic.SelectManyCheckboxListRenderer.encodeEnd(SelectManyCheckboxListRenderer.java:114)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:861)
at org.jboss.seam.ui.util.cdk.RendererBase.renderChild(RendererBase.java:190)
at org.jboss.seam.ui.util.cdk.RendererBase.renderChildren(RendererBase.java:166)
at org.jboss.seam.ui.renderkit.ValidateAllRendererBase.doEncodeChildren(ValidateAllRendererBase.java:33)
at org.jboss.seam.ui.util.cdk.RendererBase.encodeChildren(RendererBase.java:92)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
at org.jboss.seam.ui.util.cdk.RendererBase.renderChild(RendererBase.java:186)
at org.jboss.seam.ui.util.cdk.RendererBase.renderChildren(RendererBase.java:166)
at org.jboss.seam.ui.renderkit.DecorateRendererBase.doEncodeChildren(DecorateRendererBase.java:152)
at org.jboss.seam.ui.util.cdk.RendererBase.encodeChildren(RendererBase.java:92)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
at org.ajax4jsf.renderkit.RendererBase.renderChild(RendererBase.java:282)
at org.ajax4jsf.renderkit.RendererBase.renderChildren(RendererBase.java:262)
at org.richfaces.renderkit.html.PanelRenderer.doEncodeChildren(PanelRenderer.java:220)
at org.richfaces.renderkit.html.PanelRenderer.doEncodeChildren(PanelRenderer.java:215)
at org.ajax4jsf.renderkit.RendererBase.encodeChildren(RendererBase.java:121)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:930)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:148)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:930)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:933)
at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:592)
at org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:100)
at org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:176)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:110)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:266)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:390)
at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:517)
at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.HotDeployFilter.doFilter(HotDeployFilter.java:53)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:235)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:190)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:92)
at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.process(SecurityContextEstablishmentValve.java:126)
at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:330)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:829)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:601)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
at org.domain.testerelacionamento.beans.ConhecimentoBean.preencheItems(ConhecimentoBean.java:43)
at org.domain.testerelacionamento.beans.ConhecimentoBean.(ConhecimentoBean.java:32)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at java.lang.Class.newInstance0(Class.java:355)
at java.lang.Class.newInstance(Class.java:308)
at org.jboss.seam.Component.instantiateJavaBean(Component.java:1438)
at org.jboss.seam.Component.instantiate(Component.java:1359)
at org.jboss.seam.Component.newInstance(Component.java:2122)