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Question

我有一个问题要在 dataTable 中显示一些值

这是dataTable的代码

<h:form>  
    <p:dataTable var="car" value="#{competence.getAllCompetence()}">  
    <p:column headerText="Model">  
            <h:outputText value="#{car.idCompetence}" />  
        </p:column> 
        </p:dataTable>

这是查询

public List<Object> findAllCompetence() {
        // TODO Auto-generated method stub
        return getHibernateTemplate().find("select c,pro from Competence as c  join c.technologies as pro ");
    }

并且消息错误是

Grave: Error Rendering View[/default.xhtml]
java.lang.NumberFormatException: For input string: "idCompetence"
    at java.lang.NumberFormatException.forInputString(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at javax.el.ArrayELResolver.coerce(ArrayELResolver.java:159)
    at javax.el.ArrayELResolver.getValue(ArrayELResolver.java:45)
    at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:173)
    at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:200)
    at org.apache.el.parser.AstValue.getValue(AstValue.java:183)
    at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:185)


Hibernate: select competence0_.idCompetence as idCompet1_3_0_, technologi1_.idTechnologie as idTechno1_7_1_, competence0_.llibelleCompetence as llibelle2_3_0_, competence0_.description as descript3_3_0_, competence0_.niveauExpert as niveauEx4_3_0_, technologi1_.idCompetence as idCompet2_7_1_, technologi1_.libelleTechnologie as libelleT3_7_1_ from gestioncollaborateur.competence competence0_ inner join gestioncollaborateur.technologie technologi1_ on competence0_.idCompetence=technologi1_.idCompetence

我不知道问题是什么，我认为它与返回对象有关

Answer 1

您将返回一个List<Object>，数据表会对其进行迭代。每个 Object 实际上是一个 Object[]，其中第一个数组条目是 Competence 对象，第二个条目是匹配的 Technologies 条目。

JSF 尝试使用"idCompetence" 作为数组的索引但失败了。这就是您的异常的来源。试试#{car[0].idCompetence} 看看是否有帮助。