Help....Erro em um cast em uma List de Object[]?

paribe · Abril 22, 2011, 1:25pm

olá,

estou com um erro de cast na linha

for (Object[] objects : listaAlunos) {

no retorno do metodo do DAO e não estou visualizando o erro .

alguém pode me ajudar

abs

DAO

public List&lt;Object []&gt; listaDistinctAluno( ) throws DAOException{
		List&lt;Object []&gt; aluno = null;
		String hql = "";
		try {   
				hql ="SELECT distinct(nm_aluno) nm_aluno FROM resposta_aluno" ;	
		
			Query query =   (Query) HibernateUtil.getInstance().getSession().createSQLQuery(hql);
			aluno =   (List&lt;Object[]&gt;) query.list();

		} catch(Exception e) {
			System.out.println( "Não foi possÃvel encontrar Pergunta Professor  "+ e);
			throw new DAOException("Erro ao selecionar Nome de Aluno Distincto",e);
		}
		
		return aluno;				
		
	}

MB

public List&lt;SelectItem&gt; getDistinctAlunos() throws DAOException{
	
		
		try{
			if(this.distinctAlunos == null){
				this.distinctAlunos= new ArrayList&lt;SelectItem&gt;();
				
				RespostaAlunoBC alunoBC = new RespostaAlunoBC();
				List&lt;Object[]&gt; listaAlunos = alunoBC.listaDistinctAluno();
				if (listaAlunos==null){
					return distinctAlunos;	
				}
				this.distinctAlunos.add(new SelectItem("0","Todos"));
				for (Object[] objects : listaAlunos) {
					String alunoDistinct =  (String) objects[0];
					this.distinctAlunos.add(new SelectItem(alunoDistinct,alunoDistinct));
				}
			}	
		}catch(DAOException e){
			System.out.println("Erro metodo getDistinctAlunos() ="+e);
		}catch (Exception e1){
			System.out.println("Erro metodo getDistinctAlunos() ="+e1);
		}
		
		return distinctAlunos;
	}

22/04/2011 02:17:15 org.hibernate.tool.hbm2ddl.TableMetadata &lt;init&gt;
INFO : indexes: [fk4d25cd354ef56ccd, primary, fk4d25cd35a0ce33d5, papeis_id_papel] 
22/04/2011 02:17:15 org.hibernate.tool.hbm2ddl.SchemaUpdate execute
INFO : schema update complete 
Hibernate: 
    SELECT
        distinct(nm_aluno) nm_aluno 
    FROM
        resposta_aluno
22/04/2011 14:18:29 com.sun.facelets.FaceletViewHandler handleRenderException
GRAVE: Error Rendering View[/private/pages/resposta_aluno_limpeza_aluno.xhtml]
javax.faces.FacesException: javax.el.ELException: /private/pages/resposta_aluno_limpeza_aluno.xhtml @37,69 value="#{respostaAlunoMB.distinctAlunos}": Error reading 'distinctAlunos' on type ao.edu.imag.avalia.view.managedbean.RespostaAlunoMB
	at javax.faces.component.UISelectItems.getValue(UISelectItems.java:144)
	at com.sun.faces.renderkit.RenderKitUtils.getSelectItems(RenderKitUtils.java:295)
	at com.sun.faces.renderkit.html_basic.MenuRenderer.renderSelect(MenuRenderer.java:801)
	at com.sun.faces.renderkit.html_basic.MenuRenderer.encodeEnd(MenuRenderer.java:280)
	at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:856)
	at org.ajax4jsf.renderkit.RendererBase.renderChild(RendererBase.java:286)
	at org.ajax4jsf.renderkit.RendererBase.renderChildren(RendererBase.java:262)
	at org.richfaces.renderkit.html.PanelRenderer.doEncodeChildren(PanelRenderer.java:199)
	at org.richfaces.renderkit.html.PanelRenderer.doEncodeChildren(PanelRenderer.java:194)
	at org.ajax4jsf.renderkit.RendererBase.encodeChildren(RendererBase.java:121)
	at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:832)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:936)
	at javax.faces.render.Renderer.encodeChildren(Renderer.java:148)
	at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:832)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:936)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:942)
	at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:592)
	at org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
	at org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:216)
	at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:109)
	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.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:141)
	at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:281)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:301)
	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:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:558)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
	at java.lang.Thread.run(Thread.java:662)
Caused by: javax.el.ELException: /private/pages/resposta_aluno_limpeza_aluno.xhtml @37,69 value="#{respostaAlunoMB.distinctAlunos}": Error reading 'distinctAlunos' on type ao.edu.imag.avalia.view.managedbean.RespostaAlunoMB
	at com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:76)
	at javax.faces.component.UISelectItems.getValue(UISelectItems.java:141)
	... 45 more
Caused by: java.lang.ClassCastException: java.lang.String cannot be cast to [Ljava.lang.Object;
	at ao.edu.imag.avalia.view.managedbean.RespostaAlunoMB.getDistinctAlunos(RespostaAlunoMB.java:226)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at javax.el.BeanELResolver.getValue(BeanELResolver.java:62)
	at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54)
	at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72)
	at org.apache.el.parser.AstValue.getValue(AstValue.java:123)
	at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
	at com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:71)
	... 46 more
22/04/2011 14:18:29 com.sun.faces.lifecycle.Phase doPhase
GRAVE: JSF1054: (Phase ID: RENDER_RESPONSE 6, View ID: /private/pages/resposta_aluno_limpeza_aluno.xhtml) Exception thrown during phase execution: javax.faces.event.PhaseEvent[source=com.sun.faces.lifecycle.LifecycleImpl@1f07759]
22/04/2011 14:18:29 org.apache.catalina.core.StandardWrapperValve invoke
GRAVE: Servlet.service() for servlet Faces Servlet threw exception
java.lang.ClassCastException: java.lang.String cannot be cast to [Ljava.lang.Object;
	at ao.edu.imag.avalia.view.managedbean.RespostaAlunoMB.getDistinctAlunos(RespostaAlunoMB.java:226)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at javax.el.BeanELResolver.getValue(BeanELResolver.java:62)
	at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54)
	at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72)
	at org.apache.el.parser.AstValue.getValue(AstValue.java:123)
	at org.apache.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:295)
	at com.sun.faces.renderkit.html_basic.MenuRenderer.renderSelect(MenuRenderer.java:801)
	at com.sun.faces.renderkit.html_basic.MenuRenderer.encodeEnd(MenuRenderer.java:280)
	at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:856)
	at org.ajax4jsf.renderkit.RendererBase.renderChild(RendererBase.java:286)
	at org.ajax4jsf.renderkit.RendererBase.renderChildren(RendererBase.java:262)
	at org.richfaces.renderkit.html.PanelRenderer.doEncodeChildren(PanelRenderer.java:199)
	at org.richfaces.renderkit.html.PanelRenderer.doEncodeChildren(PanelRenderer.java:194)
	at org.ajax4jsf.renderkit.RendererBase.encodeChildren(RendererBase.java:121)
	at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:832)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:936)
	at javax.faces.render.Renderer.encodeChildren(Renderer.java:148)
	at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:832)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:936)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:942)
	at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:592)
	at org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
	at org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:216)
	at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:109)
	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.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:141)
	at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:281)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:301)
	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:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:558)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
	at java.lang.Thread.run(Thread.java:662)

jamirdeajr · Abril 22, 2011, 3:29pm

Do jeito que está este hql irá retornar somente um Object por linha do banco (o nome do aluno), então não é necessário um List<Object[]> , somente List já é suficiente (ou até mesmo List já que nm_aluno deve ser uma String):

[code]public List listaDistinctAluno( ) throws DAOException{
List aluno = null;
String hql = “”;
try {
hql =“SELECT distinct(nm_aluno) nm_aluno FROM resposta_aluno” ;

		Query query =   (Query) HibernateUtil.getInstance().getSession().createSQLQuery(hql);
		aluno =   (List<Object>) query.list();

	} catch(Exception e) {
		System.out.println( "Não foi possÃvel encontrar Pergunta Professor  "+ e);
		throw new DAOException("Erro ao selecionar Nome de Aluno Distincto",e);
	}
	
	return aluno;				
	
}[/code]

E:

for (Object objects : listaAlunos) { ... }
Se você incluir mais campos no Select aí o List<Object[]> seria correto, eu acho…

paribe · Abril 22, 2011, 4:02pm

obrigado pelo retorno.

deu certo…

abs

system · Dezembro 29, 2015, 7:04am

Help....Erro em um cast em uma List de Object[]?

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