java swing 中tree中数据排序

排序是经常要用到的方法，目前发现了两种方法：
1在treemodal前加一个过滤器ModalFilter的抽象类
用图比较容易明白
这是没有添加Fileter的情况：以Jlist为例（JTree，JTable差不多的）

这是添加了以后的情况

就是不管做什么。先过filter这关再说。。。
再用些代码来说话吧。！

package com.ketherware.models;

import java.util.*;
import javax.swing.*;

public abstract class AlphaSortingListModelFilter extends
                    AbstractListModel
{
// 已排序的索引数组
protected ArrayList sortedIndex;

public AlphaSortingListModelFilter(ListModel delegate)
    {
    this.delegate = delegate;//这个是实现过滤的必要的
    resort();
    }

// 该算法称为“插入排序”，适合于处理元素个数少于几百个的数据。
// 它是一种“无堆栈”排序。
protected synchronized void resort()
    {
    sortedIndex = new ArrayList();
    nextElement:
    for (int x=0; x < delegate.getSize(); x++)
        {
            for (int y=0; y < x; y++)
            {
                String current =
                    delegate.getElementAt(x).toString();
                int compareIndex =
                    ((Integer) sortedIndex.get(y)).intValue();
                String compare =
                    sortedIndex.get(compareIndex).toString();
                if (current.compareTo(compare) < 0)
                {
                    sortedList.add(new Integer(x), y);
                    continue nextElement;
                }
            }
            sortedList.add(new Integer(x));
        }
    }

    public Object getElementAt(int index)
    {
        // 委托给过滤器目标，但使用已排序的索引
        return delegate.getElementAt(sortedIndex[index]);
    }
}

这个方法的具体参考
http://www-128.ibm.com/developerworks/cn/java/j-filters/

2继承一个DefaultTreeModel类，使用super.insertNodeInto( )这个方法，把节点放入他应该在的位置
具体实现如下

// SortTreeModel.java
// This class is similar to the DefaultTreeModel, but it keeps
// a node's children in alphabetical order.
import javax.swing.tree.*;
import java.util.Comparator;

public class SortTreeModel extends DefaultTreeModel {
  private Comparator comparator;

  public SortTreeModel(TreeNode node, Comparator c) {
    super(node);
    comparator = c;
  }

  public SortTreeModel(TreeNode node, boolean asksAllowsChildren, Comparator c) {
    super(node, asksAllowsChildren);
    comparator = c;
  }

  public void insertNodeInto(MutableTreeNode child, MutableTreeNode parent) {
    int index = findIndexFor(child, parent);
    super.insertNodeInto(child, parent, index);
  }

  public void insertNodeInto(MutableTreeNode child, MutableTreeNode par, int i) {
    // The index is useless in this model, so just ignore it.
    insertNodeInto(child, par);
  }

  // Perform a recursive binary search on the children to find the right
  // insertion point for the next node.
  private int findIndexFor(MutableTreeNode child, MutableTreeNode parent) {
    int cc = parent.getChildCount( );
    if (cc == 0) {
      return 0;
    }
    if (cc == 1) {
      return comparator.compare(child, parent.getChildAt(0)) <= 0 ? 0 : 1;
    }
    return findIndexFor(child, parent, 0, cc - 1);  // First and last index
  }

  private int findIndexFor(MutableTreeNode child, MutableTreeNode parent, 
                           int i1, int i2) {
    if (i1 == i2) {
      return comparator.compare(child, parent.getChildAt(i1)) <= 0 ? i1 : i1 + 1;
    }
    int half = (i1 + i2) / 2;
    if (comparator.compare(child, parent.getChildAt(half)) <= 0) {
      return findIndexFor(child, parent, i1, half);
    }
    return findIndexFor(child, parent, half + 1, i2);
  }
}



参考Oreilly java swing 2nd 的chap 17.2