Question

我从数据库创建了一个树，并将对象作为节点。但它正在显示对象引用。我想显示对象属性值（在这种情况下为类别名称）。但我无法做到。有人知道吗？

我的类别实体如下：

@Entity
@Table(name = "category")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "Category.findAll", query = "SELECT c FROM Category c"),
    @NamedQuery(name = "Category.findByParentNullID", query = "SELECT c from Category c WHERE c.categoryParentid IS NULL"),
    @NamedQuery(name = "Category.findByCategoryCategoryid", query = "SELECT c FROM Category c WHERE c.categoryCategoryid = :categoryCategoryid"),
    @NamedQuery(name = "Category.findByCategoryName", query = "SELECT c FROM Category c WHERE c.categoryName = :categoryName"),
    @NamedQuery(name = "Category.findByCategoryParentid", query = "SELECT c FROM Category c WHERE c.categoryParentid = :categoryParentid")})
public class Category implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "category_categoryid")
    private Integer categoryCategoryid;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 45)
    @Column(name = "category_name")
    private String categoryName;
    @Column(name = "category_parentid")
    private Integer categoryParentid;
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "itemCategoryCategoryid")
    private Collection<Item> itemCollection;

public Category() {
}

public Category(Integer categoryCategoryid) {
    this.categoryCategoryid = categoryCategoryid;
}

public Category(Integer categoryCategoryid, String categoryName) {
    this.categoryCategoryid = categoryCategoryid;
    this.categoryName = categoryName;
}

public Integer getCategoryCategoryid() {
    return categoryCategoryid;
}

public void setCategoryCategoryid(Integer categoryCategoryid) {
    this.categoryCategoryid = categoryCategoryid;
}

public String getCategoryName() {
    return categoryName;
}

public void setCategoryName(String categoryName) {
    this.categoryName = categoryName;
}

public Integer getCategoryParentid() {
    return categoryParentid;
}

public void setCategoryParentid(Integer categoryParentid) {
    this.categoryParentid = categoryParentid;
}

@XmlTransient
public Collection<Item> getItemCollection() {
    return itemCollection;
}

public void setItemCollection(Collection<Item> itemCollection) {
    this.itemCollection = itemCollection;
}

@Override
public int hashCode() {
    int hash = 0;
    hash += (categoryCategoryid != null ? categoryCategoryid.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 Category)) {
        return false;
    }
    Category other = (Category) object;
    if ((this.categoryCategoryid == null && other.categoryCategoryid != null) || (this.categoryCategoryid != null && !this.categoryCategoryid.equals(other.categoryCategoryid))) {
        return false;
    }
    return true;
}

@Override
public String toString() {
    return "com.synergytech.ims.entities.Category[ categoryCategoryid=" + categoryCategoryid + " ]";
}

}

和我的CategoryController是这样的：

@ManagedBean
@ViewScoped
public class CategoryController {

    @EJB
    CategoryFacade categoryFacade;
    Category current;
    List<Category> categorylist;
    private TreeNode root;
    private TreeNode actualRoot, tempRoot;
    private TreeNode selectedNode;

    public CategoryFacade getCategoryFacade() {
        return categoryFacade;
    }

    public Category getCurrent() {
        return current;
    }

    public void setCurrent(Category current) {
        this.current = current;
    }

    public CategoryController() {
    }

    public List<Category> getCategorylist() {
        categorylist = getCategoryFacade().findAll();
        return categorylist;
    }

    public void setCategorylist(List<Category> categorylist) {
        this.categorylist = categorylist;
    }

    public TreeNode getRoot() {
        return root;
    }

    public void setRoot(TreeNode root) {
        this.root = root;
    }

    public TreeNode getSelectedNode() {
        return selectedNode;
    }

    public void setSelectedNode(TreeNode selectedNode) {
        this.selectedNode = selectedNode;
    }

    public void prepareCreate() {
        if (current == null) {
            current = new Category();
        }
    }

    public List<Category> All() {
        return getCategoryFacade().findAll();
    }

    public TreeNode makeTree() {
        root = new DefaultTreeNode("Root", null);
        actualRoot = new DefaultTreeNode("Root", null);
        categorylist = getCategoryFacade().getByParentNullID();
        for (Iterator<Category> it = categorylist.iterator(); it.hasNext();) {
            Category category = it.next();
            actualRoot = new DefaultTreeNode(category.getCategoryName(), root);
            createTree(category.getCategoryCategoryid(), category.getCategoryName(), actualRoot);
            actualRoot.setParent(root);
        }
        return root;
    }

    public void createTree(Integer Pid, String categoryName, TreeNode subRoot) {
        List<Category> subRootList;
        subRootList = getCategoryFacade().getByParentID(Pid);
        if (!subRootList.isEmpty()) {
            for (Iterator<Category> it = subRootList.iterator(); it.hasNext();) {
                Category category = it.next();
                TreeNode node = new DefaultTreeNode(category.getCategoryName(), subRoot);
                createTree(category.getCategoryCategoryid(), category.getCategoryName(), node);
            }
        }
    }

    public void onNodeSelect(NodeSelectEvent event) {
        String categoryName = event.getTreeNode().toString();
        Integer pid = getCategoryFacade().getByCategoryName(categoryName);
        prepareCreate();
        getCurrent().setCategoryParentid(pid);
        FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_INFO, "Selected", categoryName);
        FacesContext.getCurrentInstance().addMessage(null, message);
        //RequestContext context = RequestContext.getCurrentInstance();
        //context.execute("createDialog.show();");
    }

    public void onNodeUnselect(NodeUnselectEvent event) {
        FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_INFO, "Unselected", event.getTreeNode().toString());

        FacesContext.getCurrentInstance().addMessage(null, message);
    }
}

和我显示树的xhtml代码是这样的：

<?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">
<ui:composition 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"
                xmlns:p="http://primefaces.org/ui">    
<h:form id="CategoryListForm">        
    <p:growl id="growl" showDetail="true" sticky="false"/>
        <p:panel header="Category List"> 
           <p:tree value="#{categoryController.makeTree()}" var="node" dynamic="true" cache="false" selectionMode="single"  selection="#{categoryController.selectedNode}" id="tree"> 
              <p:ajax event="select" update=":CategoryListForm:growl" listener="#{categoryController.onNodeSelect}"/>  
              <p:ajax event="unselect" update=":CategoryListForm:growl" listener="#{categoryController.onNodeUnselect}"/>  


          <p:treeNode> 
                    <h:outputText value="#{node}" /> 
             </p:treeNode>
          </p:tree>
          <f:facet name="footer"> 
               <div class="footer-section">

         <p:commandButton id="createButton" icon="ui-icon-plus"   value="Create" action="#{categoryController.prepareCreate()}" oncomplete="CategoryCreateDialog.show()"/>                  

               </div>
          </f:facet>
      </p:panel> 
</h:form>
</ui:composition>

我只想在树中的xhtml中显示属性值。但是，当我从树中选择节点时，我希望不仅要选择属性值。

Answer 1

<h:outputText value="#{node}" />

这隐式调用node.toString()，即TreeNode.toString()，显然会返回Object.toString()返回的内容。您需要选择要显示的节点的字段。

带有PrimeFaces的Java Server Faces树

1 个答案: