SWT/JFace从数据库表生成treeviewer所需要的内容（list对象）

网上关于SWT/JFace的Treeviewer应用的文章有很多，值得推荐的是：http://www.cnblogs.com/huqingyu/archive/2008/04/10/1146209.html
，但是至于如何从数据库中获得TreeMenuContentProvider所需要的树状list，没有太多实例，下面是我写的一个例子，供大家参考：
共分为以下几步：
一、创建数据库表tree_menu_t(tree_menu_id,tree_menu_text,tree_menu_pid,tree_menu_action);
并填充数据
举例：

tree_menu_id	tree_menu_text	tree_menu_pid	tree_menu_action
1	系统设置	0	null
2	用户设置	1	user_action
3	角色设置	1	role_action
4	权限设置	1	privilege_action
5	业务模块	0	null
6	销售管理	5	sale_action

创建对应类：

package com.project.layout.treemenu;

import java.util.*;

import com.bsm.user.User;

public class TreeMenu {
	private String treeMenuId;
	private String treeMenuPid;
	private String treeMenuText;
	private String treeMenuAction;
	private List children = new ArrayList();

	public TreeMenu(String treeMenuId, String treeMenuPid,String treeMenuText,String treeMenuAction, ArrayList children) {
		this.treeMenuId = treeMenuId;
		this.treeMenuPid = treeMenuPid;
		this.treeMenuText = treeMenuText;
		this.treeMenuAction = treeMenuAction;
		this.children = children;
	}

	public String getTreeMenuAction() {
		return treeMenuAction;
	}

	public void setTreeMenuAction(String treeMenuAction) {
		this.treeMenuAction = treeMenuAction;
	}

	public TreeMenu() {

	}

	public String getTreeMenuId() {
		return treeMenuId;
	}

	public void setTreeMenuId(String treeMenuId) {
		this.treeMenuId = treeMenuId;
	}

	public String getTreeMenuPid() {
		return treeMenuPid;
	}

	public void setTreeMenuPid(String treeMenuPid) {
		this.treeMenuPid = treeMenuPid;
	}

	public String getTreeMenuText() {
		return treeMenuText;
	}

	public void setTreeMenuText(String treeMenuText) {
		this.treeMenuText = treeMenuText;
	}

	public List getChildren() {
		return children;
	}

	public void setChildren(List children) {
		this.children = children;
	}
}

第二步：创建DAO，获取对应数据list

package com.project.layout.treemenu;

import java.util.ArrayList;
import java.util.List;
public class TreeMenuDAO {
	public List getTreeMenuList() {
		String sql = "SELECT TREE_MENU_ID , TREE_MENU_TEXT , TREE_MENU_PID , TREE_MENU_ACTION FROM TREE_MENU_T ORDER BY TREE_MENU_PID,TREE_MENU_ID;";
		
 list = new ArrayList();
//具体取语句就不多说了，因为关于从表中取得数据的实例太多了，各个人又个人的不同实现方法
    treeMenu = new TreeMenu();
    treeMenu.setTreeMenuId(s[i][j++]);
    treeMenu.setTreeMenuText(s[i][j++]);
    treeMenu.setTreeMenuPid(s[i][j++]);
    treeMenu.setTreeMenuAction(s[i][j++]);
    list.add(treeMenu);
    return list;//返回list对象
	}
}

第三步：拼装成链状list

package com.project.layout.treemenu;

import com.bsm.user.User;
import java.util.List;
import java.util.ArrayList;

public class TreeMenuBO {
	private TreeMenu tm = new TreeMenu();
	private List tList = new ArrayList();
	public List getTreeViewList() {
		TreeMenu treeMenu = new TreeMenu();
		TreeMenuDAO dao = new TreeMenuDAO();
		List list = dao.getTreeMenuList();
		this.tm = new TreeMenu("0", "0", "root", "", new ArrayList());// 设置顶级元素，为了便于子list的挂载，在返回时候，去掉
		tList.add(tm);

		for (int i = 0; i < list.size(); i++) {
			this.tm = (TreeMenu) list.get(i);
			assembleTreeList(tList);
		}
		return ((TreeMenu) tList.get(0)).getChildren();//去掉顶级节点
	}

	public void assembleTreeList(List list) {//对已经存在的list链进行循环遍历
		for (int i = 0; i < list.size(); i++) {
			TreeMenu treeMenu = (TreeMenu) list.get(i);
			// System.out.println("--" + treeMenu.getTreeMenuText());
			if (treeMenu.getTreeMenuId().equals(this.tm.getTreeMenuPid())) {//取得父子对应关系
				treeMenu.getChildren().add(this.tm);//挂载子
			}
			if (treeMenu.getChildren() != null) {
				assembleTreeList(treeMenu.getChildren());
			}
		}
	}
}

第四部：应用

package com.project.layout.treemenu;

import org.eclipse.jface.viewers.*;
import java.util.List;

public class TreeMenuContentProvider implements ITreeContentProvider {
	public Object[] getElements(Object inputElement) {
		if (inputElement instanceof List) {
			List input = (List) inputElement;
			return input.toArray();
		}
		return new Object[0];
	}

	public Object[] getChildren(Object parentElement) {
		TreeMenu tm = (TreeMenu) parentElement;
		List list = tm.getChildren();
		if (list == null) {
			return new Object[0];
		}
		return list.toArray();

	}

	public boolean hasChildren(Object element) {
		TreeMenu tm = (TreeMenu) element;
		List list = tm.getChildren();
		return !(list == null || list.isEmpty());

	}

	public Object getParent(Object element) {
		return null;
	}

	public void dispose() {
	}

	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
	}

}

package com.project.layout.treemenu;

import org.eclipse.jface.viewers.*;
import org.eclipse.swt.graphics.Image;

public class TreeMenuLableProvider implements ILabelProvider {
	public Image getImage(Object element) {
		// ISharedImages sharedImages =
		// PlatformUI.getWorkbench().getSharedImages();
		// return sharedImages.getImage(ISharedImages.IMG_OBJS_WARN_TSK);
		return null;
	}

	public void dispose() {
	}

	public void addListener(ILabelProviderListener listener) {
	}

	/**
	 * 显示什么文字
	 * 
	 * @param 结点
	 * @return 不能为null值
	 */
	public String getText(Object element) {
		return (String) ((TreeMenu)element).getTreeMenuText();
	}

	public boolean isLabelProperty(Object element, String property) {
		return false;
	}
	public void removeListener(ILabelProviderListener listener) {}

}

最终只需要维护好数据库表，就能够成功展现treeviewer了，不知道大家有没有更好的办法互相交流一下。