Question

我正在尝试搜索我使用JSF开发的数据库作为前端技术。我收到一条错误说明如下：

无法找到带[0]参数的方法[searchContractors]

这是我使用过的代码。任何人都可以告诉我，如果有明显的事情我做错了，因为我无法理解为什么我会收到这个错误。谢谢你的帮助。

JSF代码

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">

<head>
<title>Search</title>
</head>
<body>
<h:form id="searchForm">
    <H2>Search</H2>
    <H4>Please select the county that you live in.
    </H4>
    <table>

        <tr>
            <td><h:outputLabel for="county">
                    <h:outputText id="countyLabel" value="County" />
                </h:outputLabel></td>

            <td><h:selectOneMenu id="countyName"
                    value="#{searchBean.countyId}">
                    <f:selectItems value="#{registerBean.counties}" var="county"
                        itemLabel="#{county.name}" itemValue="#{county.id}" />
                </h:selectOneMenu></td>
        </tr>
        <tr>
            <td><h:commandButton id="searchContractors"
                    action="#{searchBean.searchContractors(searchBean.countyId)}">
                    <h:outputText value="Search Contractors" />
    </table>

</h:form>
</body>
</html>

Java代码

@ManagedBean
@SessionScoped
public class SearchBean implements Serializable {

private static final long serialVersionUID = -2107387060867715013L;
private static final String PERSISTENCE_UNIT_NAME = "NeedABuilderUnit";
private static EntityManagerFactory factory;
private int countyId;

public List<BusinessAccount> searchContractors(int countyId) {
    factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
    EntityManager em = factory.createEntityManager();   
    List<BusinessAccount> contractorList = new ArrayList<BusinessAccount>();

        em.getTransaction().begin();
        Query myQuery = em.createQuery("SELECT u FROM BusinessAccount u WHERE u.county.id=:CountyId");
        myQuery.setParameter("CountyId", countyId);

        contractorList=myQuery.getResultList();
        em.getTransaction().commit();
        em.close();

        return contractorList;

    } 


public int getCountyId() {
    return countyId;
}

public void setCountyId(int countyId) {
    this.countyId = countyId;
}   
}

Answer 1

以下内容应该有效：

<ui:param name="countyId" value="#{searchBean.countyId}" />
...
<h:commandButton id="searchContractors" 
    action="#{searchBean.searchContractors(countyId)}">

为什么我在JSF页面中收到此错误？

1 个答案: