java - 删除JSF dataTable中数据库的行

当我运行并按下按钮“删除”时，页面向我显示此错误：

无法找到匹配的导航案例，其导航ID为'/ApagarCategoria.xhtml'，动作为'＃{registarVendedor.deleteCtg（c）}'，结果为[[entities.Categorias [categoria = Carro]]'

控制者

在RegistoVendedor.java中，该函数是公共List deleteCtg（Categorias ct）

package Controller;


public class RegistoVendedor {

@EJB
RegistoBean registarVendedor;

String contacto;
String password;

Categorias categoria = new Categorias();


List<Categorias> categoriasList = new ArrayList<>();

public List<Categorias> getCategoriasList() {
    return categoriasList;
}

public void setCategoriasList(List<Categorias> categoriasList) {
    this.categoriasList = categoriasList;
}

public List<Categorias> deleteCtg(Categorias ct) {
    categoriasList = registarVendedor.removeCtg(ct);
    return categoriasList;
}
}

在RegistoBean.java中，该函数是公共List removeCtg（Categorias ct）

@Stateless
public class RegistoBean {

@PersistenceContext
EntityManager em;

public List<Categorias> removeCtg(Categorias ct){
    em.createNamedQuery("Categorias.removeCategoria");
    return getCtg();
}

public List<Categorias> getCtg(){
    return (List<Categorias>) em.createNamedQuery("Categorias.findAll").getResultList();
}
}

Categorias.java数据库

@Entity
@Table(name = "CATEGORIAS")
@XmlRootElement
@NamedQueries({
@NamedQuery(name = "Categorias.findAll", query = "SELECT c FROM Categorias c")
, @NamedQuery(name = "Categorias.findByCategoria", query = "SELECT c FROM Categorias c WHERE c.categoria = :categoria")
, @NamedQuery(name = "Categorias.removeCategoria", query = "DELETE FROM Categorias c WHERE c.categoria = :categoria")})
public class Categorias implements Serializable {

private static final long serialVersionUID = 1L;
@Id
@Basic(optional = false)
@NotNull
@Size(min = 1, max = 200)
@Column(name = "CATEGORIA")
private String categoria;
@OneToMany(cascade = CascadeType.ALL, mappedBy = "categoriaCategorias")
private Collection<Produtos> produtosCollection;

public Categorias() {
}

public Categorias(String categoria) {
    this.categoria = categoria;
}

public String getCategoria() {
    return categoria;
}

public void setCategoria(String categoria) {
    this.categoria = categoria;
}

@XmlTransient
public Collection<Produtos> getProdutosCollection() {
    return produtosCollection;
}

public void setProdutosCollection(Collection<Produtos> produtosCollection) {
    this.produtosCollection = produtosCollection;
}

@Override
public int hashCode() {
    int hash = 0;
    hash += (categoria != null ? categoria.hashCode() : 0);
    return hash;
}

@Override
public boolean equals(Object object) {
    // TODO: Warning - this method won't work in the case the id fields are not set
    if (!(object instanceof Categorias)) {
        return false;
    }
    Categorias other = (Categorias) object;
    if ((this.categoria == null && other.categoria != null) || (this.categoria != null && !this.categoria.equals(other.categoria))) {
        return false;
    }
    return true;
}

@Override
public String toString() {
    return "entities.Categorias[ categoria=" + categoria + " ]";
}

}

ApagarCategoria.xhtml

<?xml version='1.0' encoding='UTF-8' ?>
<!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:h="http://xmlns.jcp.org/jsf/html"
  xmlns:f="http://xmlns.jcp.org/jsf/core">
<h:head>
    <title>Apagar Categoria</title>
</h:head>
<h:body>
    <br></br>
    <div align="center" >
        <h1 align="center">Lista de Categorias</h1>

        <div align ="center">
<h:form>
            <h:dataTable value = "#{registarVendedor.listarCategorias()}" var = "c"
                         styleClass = "authorTable"
                         headerClass = "authorTableHeader"
                         rowClasses = "authorTableOddRow,authorTableEvenRow"
                         width = "600">

                <h:column><f:facet name = "header"> Categoria </f:facet>
                        #{c.categoria}
                    <f:facet name = "header2"> </f:facet>
                </h:column>
                <h:column>

                    <p> <h:commandButton value="Delete" class="button1" action="#{registarVendedor.deleteCtg(c)}">
                                    <f:setPropertyActionListener target="#{registarVendedor.categoria}" value="#{c}"/>
                                </h:commandButton></p>

                </h:column>

            </h:dataTable>
</h:form>
        </div>
        <h:form >
            <p> <h:commandButton value="Voltar" class="button1" action="MenuVendedor"></h:commandButton></p>
        </h:form>
    </div>
</h:body>

我知道同样有疑问，但是我已经尝试了解决方案，但没有用

最佳答案

错误是

找不到匹配的导航

JSF使用返回值“＃{registarVendedor.deleteCtg（c）}”来确定下一步应查看哪个视图。但是您返回一个列表，所以jsf迷路了。您需要返回String或void。

如果这样做，它将起作用

public void deleteCtg(Categorias ct) {
     categoriasList = registarVendedor.removeCtg(ct);
}

您真的需要那个清单吗？您可以使用getCategoriasList()获得它。