使用遞歸從數據庫構建primefaces樹

我正在使用primefaces樹組件。我遇到了使用遞歸從數據庫構建樹的問題。我看過這個問題Primefaces tree from database。但是，我無法構建樹。我在for循環中有一個getChildNodes列表，因爲它是遞歸函數，所以它被重複調用。我無法修復它。以下是我的代碼。使用遞歸從數據庫構建primefaces樹

實體

package com.model; 

import java.io.Serializable; 
import javax.persistence.*; 
import javax.persistence.Id; 


/** 
* The persistent class for the tree database table. 
* 
*/ 
@Entity 
@Table(name = "TREE") 
public class Tree implements Serializable { 
    private static final long serialVersionUID = 1L; 

    @Id 
    @Column(name="NODE_ID") 
    private int nodeId; 

    @Column(name="NODE_DATA") 
    private String nodeData; 

    @Column(name="PARENT_ID") 
    private int parentId; 

    @Column(name="NODE_TYPE") 
    private String nodeType; 

    public Tree() { 
    } 

    public int getNodeId() { 
     return this.nodeId; 
    } 

    public void setNodeId(int nodeId) { 
     this.nodeId = nodeId; 
    } 

    public String getNodeData() { 
     return this.nodeData; 
    } 

    public void setNodeData(String nodeData) { 
     this.nodeData = nodeData; 
    } 

    public int getParentId() { 
     return this.parentId; 
    } 

    public void setParentId(int parentId) { 
     this.parentId = parentId; 
    } 

    public String getNodeType() { 
     return nodeType; 
    } 

    public void setNodeType(String nodeType) { 
     this.nodeType = nodeType; 
    } 


}

ManagedBean

package com.managedBeans; 

import java.util.ArrayList; 
import java.util.List; 

import javax.annotation.PostConstruct; 

import org.primefaces.model.DefaultTreeNode; 
import org.primefaces.model.TreeNode; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.context.annotation.Scope; 
import org.springframework.stereotype.Component; 

import com.model.Tree; 
import com.service.TreeService; 

/** 
* @author ADMIN 
* 
*/ 

@Component("treeBeanRecursive") 
@Scope("request") 
public class TreeBeanRecursive { 

    private TreeNode rootNode; 

    @Autowired 
    TreeService treeService; 

    private List<Tree> childNodes; 

    public TreeService getTreeService() { 
     return treeService; 
    } 

    public void setTreeService(TreeService treeService) { 
     this.treeService = treeService; 
    } 

    public TreeBeanRecursive() { 

    } 

    @PostConstruct 
    public void init() { 

     Tree root = treeService.getRoot(); 

     childNodes = treeService.getChildNodes(); 

     rootNode = getNodeWithChildren(root, null); 

    } 

    public TreeNode getNodeWithChildren(Tree t1, TreeNode parent){ 
     TreeNode newNode= new DefaultTreeNode(t1, parent); 

     for (Tree tt : childNodes){ 
      TreeNode newNode2= getNodeWithChildren(tt, newNode); 
     } 

     return newNode; 
    } 



    public TreeNode getRootNode() { 
     return rootNode; 
    } 

    public void setRootNode(TreeNode node) { 
     rootNode = node; 
    } 

    public void showMessage() { 
     treeService.showMessage(); 
    } 

    public List<Tree> getChildNodes() { 
     return childNodes; 
    } 

    public void setChildNodes(List<Tree> childNodes) { 
     this.childNodes = childNodes; 
    } 

}

的childNodes是除了根節點的所有節點的列表。我從春季服務treeService.getChildNodes（）獲取列表;

tree.xhtml

<html xmlns="http://www.w3.org/1999/xhtml" 
    xmlns:h="http://java.sun.com/jsf/html" 
    xmlns:f="http://java.sun.com/jsf/core" 
    xmlns:p="http://primefaces.org/ui"> 
<h:head> 
    <link type="text/css" rel="stylesheet" href="themes/bluesky/skin.css" /> 
    <style type="text/css"> 
.ui-panel { 
    font-size: 85% !important; 
    font-family: calibri !important; 
    align: "center" !important; 
} 

.customProjectNode { 
    background-image: url(./../images/tree/root.png) !important; 
    width: 17px; 
    height: 16px; 
} 
</style> 
</h:head> 
<h:body> 


    <h:form id="form"> 

     <p:tree value="#{treeBeanRecursive.rootNode}" var="node" id="tree"> 
      <p:treeNode> 
       <h:outputText value="#{node.getNodeData()}" /> 
      </p:treeNode> 
      <p:treeNode type="#{node.getNodeType()}" icon="customProjectNode"> 
       <h:outputText value="#{node.getNodeData()}" /> 
      </p:treeNode> 
     </p:tree> 


    </h:form> 

</h:body> 
</html>

我的表中有以下數據。根節點的父是0

節點ID數據PARENTID節點類型

'1'， '項目名稱'， '0'， '項目名'

'2'， '節點1'，「1 」， '硬件'

'3'， '節點2'， '1'， '軟件'

'4'， '節點3'， '1'， '軟件'

'5'，'Node4'，'2'，'hardware'

來源

2012-09-13 neni

最後，我能夠解決我自己的問題。這是修復。更新ManagedBean

@Component("treeBeanRec") 
@Scope("view") 
public class TreeBeanRec { 

    private TreeNode rootNode; 

    private TreeNode selectedNode; 

    @Autowired 
    TreeService treeService; 

    public TreeService getTreeService() { 
     return treeService; 
    } 

    public void setTreeService(TreeService treeService) { 
     this.treeService = treeService; 
    } 

    public TreeBeanRec() { 

    } 

    @PostConstruct 
    public void init() { 

     Tree root = treeService.getRoot(); 

     rootNode = new DefaultTreeNode("Root", null); 


     TreeNode t1 = createTree(root, rootNode); 


    } 

    // Recursive function to create tree 

    public TreeNode createTree(Tree treeObj, TreeNode rootNode) { 
     TreeNode newNode = new DefaultTreeNode(treeObj, rootNode); 

     List<Tree> childNodes1 = treeService.getChildNodes(treeObj.getNodeId()); 

     for (Tree tt : childNodes1) { 
      TreeNode newNode2 = createTree(tt, newNode); 
     } 

     return newNode; 
    } 

    public TreeNode getRootNode() { 
     return rootNode; 
    } 

    public void setRootNode(TreeNode node) { 
     rootNode = node; 
    } 

}

來源

2012-09-13 11:32:30 neni

使用遞歸從數據庫構建primefaces樹

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