从JTree中的文本文件动态填充树模型 [英] Dynamically populating the tree model from a text file in JTree

问题描述

我正在面对的问题是JTree的树型模型。

我已经将根节点定义为：

  javax.swing.tree.DefaultMutableTreeNode rootNode = new javax.swing.tree.DefaultMutableTreeNode（projectName）; 
  

当应用程序首次启动时，我想要创建和加载treeModel。
为此，我使用的文件是meta.txt，它具有如下信息：

  1QuotesPrice.Job 
 2QuotesPrice.Df 
 1Quotes.Job 
 2Quotes.Wf 
 3Quotes.Df 
 2Falkeblang.Wf 
 3Falkeblang.Df 
  

第一列是级别，第二列是树的节点。
根据这些信息，我想创建树模型，但是在这里面临着一个路障。

我不确定要应用于添加的逻辑上述节点到根节点。
我尝试过的每件事似乎都有缺陷。
这里的问题是没有级别不是固定的，所以我不能简单地使用if-else结构。
我使用以下代码：

  String treeMeta = this.projectsDir +\\+ projectName + \\ + meta.txt; 
 DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode（projectName）; 
文件f1 =新建文件（treeMeta）; 
 inputStream = new Scanner（f1）; 
 while（inputStream.hasNext（））{
 
 String val = inputStream.next（）; 
 System.out.println（！@＃$％+ val +！@＃$％）; 
 treeNodePrev = treeNode; 
 prevLevel = level; 
 level = val.substring（0,1）; 
 nodeVal = val.substring（1）; 
 if（level.equals（1））{
 prevNode = projectName; 
 treeNode = new DefaultMutableTreeNode（nodeVal）; 
 System.out.println（添加到根节点）; 
 rootNode.add（treeNode）; 
 //System.out.println(\" addded to root node）; 
} else if（Integer.parseInt（level）> Integer.parseInt（prevLevel））{
 prevNode = nodeVal; 
 treeNode = new DefaultMutableTreeNode（nodeVal）; 
 treeNodePrev.add（treeNode）; 
} else if（Integer.parseInt（level）== Integer.parseInt（prevLevel））{
 prevNode = nodeVal; 
 treeNode = new DefaultMutableTreeNode（nodeVal）; 
 prevParentTreeNode =（DefaultMutableTreeNode）treeNodePrev.getParent（）; 
 //System.out.println(prevParentTreeNode.getParent（）。toString（））; 
 prevParentTreeNode.add（treeNode）; 
} 
} 
 jProjectTree.setModel（new javax.swing.tree.DefaultTreeModel（rootNode））; 
 jScrollPane2.setViewportView（jProjectTree）; 
  

这似乎工作正常，但任何人都可以告诉我，这是否是正确的方法？ / p>

解决方案

这可能有点清洁。只需调整计算级别的功能...

  public static final DefaultMutableTreeNode getTreeNode（File file）throws IOException {
 
 DefaultMutableTreeNode rootNode = null; 
 Map< Integer，DefaultMutableTreeNode> levelNodes = new HashMap< Integer，DefaultMutableTreeNode>（）; 
 BufferedReader reader = new BufferedReader（new FileReader（file））; 
字符串; 
 
 while（（line = reader.readLine（））！= null）{
 
 int level = getLevel（line）; 
 String nodeName = getNodeName（line，level）; 
 DefaultMutableTreeNode node = new DefaultMutableTreeNode（nodeName）; 
 levelNodes.put（level，node）; 
 DefaultMutableTreeNode parent = levelNodes.get（level  -  1）; 
 
 if（parent！= null）{
 parent.add（node）; 
} 
 else {
 rootNode = node; 
} 
} 
 reader.close（）; 
返回rootNode; 
} 
 
 private static final int getLevel（String line）{
 
 int level = 0; （int i = 0; i< line.length（）; i ++）{
 char c = line.charAt（i）; 
 
 if（c =='\t'）{
 level ++; 
} 
 else {
 break; 
} 
} 
返回级别; 
} 
 
 private static final String getNodeName（String line，int level）{
 return line.substring（level）; 
} 
  

The problem I am facing is with the tree model of the JTree.

I have defined the root node as:

    javax.swing.tree.DefaultMutableTreeNode rootNode = new javax.swing.tree.DefaultMutableTreeNode(projectName);

When the application first starts, I want the treeModel to be created and loaded. For this, I am using a file meta.txt, which has information like the following:

    1QuotesPrice.Job
    2QuotesPrice.Df
    1Quotes.Job
    2Quotes.Wf
    3Quotes.Df
    2Falkeblang.Wf
    3Falkeblang.Df

The first column is the level, and the second is the node of the tree. Now based on this information, I want to create the tree model, but am facing a roadblock here.

I am unsure of the logic to apply to add the above nodes to the root node. Every thing I have tried seems to have flaws. The problem here is the no of levels are not fixed, so I cant simply use a if-else construct. I am using the following code:

        String treeMeta=this.projectsDir+"\\"+projectName+"\\"+"meta.txt";
        DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode(projectName);
        File f1=new File(treeMeta);
        inputStream =  new Scanner(f1);
        while(inputStream.hasNext()){

         String val=inputStream.next();
         System.out.println("!@#$%"+val+"!@#$%");
         treeNodePrev=treeNode;
         prevLevel=level;
         level=val.substring(0,1);
         nodeVal=val.substring(1);
           if(level.equals("1")){
              prevNode=projectName;
              treeNode = new DefaultMutableTreeNode(nodeVal);
              System.out.println("added to root node");
              rootNode.add(treeNode);
              //System.out.println("added to root node");
           }else if(Integer.parseInt(level)>Integer.parseInt(prevLevel)){
               prevNode=nodeVal;
               treeNode = new DefaultMutableTreeNode(nodeVal);
               treeNodePrev.add(treeNode);
           }else if(Integer.parseInt(level)==Integer.parseInt(prevLevel)){
               prevNode=nodeVal;
               treeNode = new DefaultMutableTreeNode(nodeVal);
               prevParentTreeNode=(DefaultMutableTreeNode)treeNodePrev.getParent();
               //System.out.println(prevParentTreeNode.getParent().toString());
               prevParentTreeNode.add(treeNode);
           }
        }
         jProjectTree.setModel(new javax.swing.tree.DefaultTreeModel(rootNode));
         jScrollPane2.setViewportView(jProjectTree);

This seems to be working fine, but could anyone please tell me if this is the correct approach?

解决方案

This might be a bit cleaner. Just adapt the function for calculating the level ...

public static final DefaultMutableTreeNode getTreeNode(File file) throws IOException  {

    DefaultMutableTreeNode rootNode = null;
    Map<Integer, DefaultMutableTreeNode> levelNodes = new HashMap<Integer, DefaultMutableTreeNode>();
    BufferedReader reader = new BufferedReader(new FileReader(file));
    String line;

    while( (line = reader.readLine()) != null ) {

        int level = getLevel(line);
        String nodeName = getNodeName(line, level);
        DefaultMutableTreeNode node = new DefaultMutableTreeNode(nodeName);               
        levelNodes.put(level, node);
        DefaultMutableTreeNode parent = levelNodes.get(level - 1);

        if( parent != null ) {
            parent.add(node);
        }
        else {
            rootNode = node;
        }
    }    
    reader.close();
    return rootNode;
}

private static final int getLevel(String line) {

    int level = 0;
    for ( int i = 0; i < line.length(); i++ ) {
        char c = line.charAt(i);
        if( c == '\t') {
            level++;
        }
        else {
            break;
        }
    }
    return level;
}

private static final String getNodeName(String line, int level) {
    return line.substring(level);
}      

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