java+SpringMvc——查询数据，以树形结构显示

三省农场服务平台有一个业务是从数据库中查询信息，在界面上显示，显示的样式为树形结构，做到动态的变化，以前也实现过这样的功能，可能方法上略有不同，我们看下这个是怎么样实现的吧！



效果图：



红色框中的数据是从数据库中查询出来，显示在界面上的.

一、前台jsp页面

这里用的是SpringMvc，调用Action

<span style="font-family:KaiTi_GB2312;font-size:18px;"><?xml version="1.0" encoding="UTF-8"?>
<left layout="农场管理">
	<tab id="1">
		<accordion>
			<node id="CAIPINTREE" name="菜品管理" type="tree" url="${path}/DishCategory/left_caipin.json" expand="first">
			</node>
			<node name="信息管理">
				<node id="CZZX" name="采摘资讯" type="ZXGL" icon="pinguo.png"></node>
				<node id="NZDT" name="农庄动态" type="ZXGL" icon="newspaper.png"></node>
				<node id="PSGL" name="配送计划" type="PSGL" icon="Home.png"></node>
			</node>
			<node id="ZZGLTREE" name="种植管理" type="tree" url="${path}/zhongzhi/lefttree.json" expand="first">
			</node>
			<node id="YZGLTREE" name="养殖管理" type="tree" url="${path}/zixun/left_yzgl.json" expand="first">
			</node>
			<node id="JGSCTREE" name="生产管理" type="tree" url="${path}/zixun/left_jgsc.json" expand="first">
			</node>
			<node id="ZCGLTREE" name="资产管理" type="tree" url="${path}/Property/left_zcgl.json" expand="first">
			</node>
		</accordion>
		
	</tab>
</left></span>

二、Action

<span style="font-family:KaiTi_GB2312;font-size:18px;">	/****
	 * 显示界面左侧树 韩欣桐 2015年12月23日
	 * 
	 * @param pdatatype
	 * @param pcustattr
	 * @param pid
	 * @param request
	 * @return
	 */
	@RequestMapping(value = "/left_zichan.json", method = { RequestMethod.GET,
			RequestMethod.POST })
	@ResponseBody
	public Object left_zichan(String pdatatype, String pcustattr, String pid,
			HttpServletRequest request) {

		// 判断树父id是否为空
		if (StringUtil.isEmpty(pid)) {
			List<TreeNode> list = new ArrayList<TreeNode>();
			return list;
		} else {
			List<TreeNode> list = new ArrayList<TreeNode>();
			return list;
		}
	}

	/**
	 * 通过资产分类，查询资产分类目录树 韩欣桐 2015年12月23日
	 * 
	 * @param pdatatype
	 * @param pcustattr
	 * @param pid
	 * @param request
	 * @return TODO
	 */
	@RequestMapping(value = "/left_zcgl.json", method = { RequestMethod.GET,
			RequestMethod.POST })
	@ResponseBody
	public Object left_zcgl(String pdatatype, String pcustattr, String pid,
			HttpServletRequest request) {
		// 判断树父id是否为空
		if (StringUtil.isEmpty(pid)) {
			List<TreeNode> list = new ArrayList<TreeNode>();
			TreeNode root = new TreeNode("0", "资产分类", "ZCGLFL", null, true);
			list.add(root);
			return list;
		} else {
			List<TreeNode> list = new ArrayList<TreeNode>();
			// 查询资产分类下面的资产分类名称
			List<SnAssetCategory> listAssetCategory = propertyService
					.QueryAllAssetName();
			// 遍历获取子节点，未加载大图缩略图
			for (int i = 0; i < listAssetCategory.size(); i++) {
				list.add(new TreeNode(((SnAssetCategory) listAssetCategory
						.get(i)).getCateuuid(),
						((SnAssetCategory) listAssetCategory.get(i))
								.getCatename(), "ZCGL", null, false));
			}

			return list;
		}
	}</span>

三、service

<span style="font-family:KaiTi_GB2312;font-size:18px;">	/****
	 * 查询所以资产分类信息-左侧树结构 
	 * 
	 * @return
	 */
	public List<SnAssetCategory> QueryAllAssetName() {
		// hql查询所有的资产分类对象
		String hql = " from SnAssetCategory";
		// 查询资产分类的对象
		List<SnAssetCategory> listAssetCategory = this.listByHql(hql);
		// 返回list集合
		return listAssetCategory;
	}</span>

四、公共的类：

<span style="font-family:KaiTi_GB2312;font-size:18px;">public class TreeNode extends BaseNode {
	private String pid; // 上级数据ID
	private boolean isParent; // 是否显示为父节点
	private boolean notclick; // 是否可点击
	private boolean dynamic; // 是否包含动态标签
	private String iconSkin; // 图标CSS
	private List<TreeNode> children;

	public TreeNode() {
	}

	public TreeNode(String id, String name, boolean isParent) {
		this.id = id;
		this.name = name;
		this.isParent = isParent;
	}

	public TreeNode(String id, String name, String type, String field,
			boolean isParent) {
		this.id = id;
		this.name = name;
		this.type = type;
		this.field = field;
		this.isParent = isParent;
	}

	public TreeNode(String id, String name, String type, String field,
			boolean isParent, String icon) {
		this.id = id;
		this.name = name;
		this.type = type;
		this.field = field;
		this.isParent = isParent;
		this.icon = icon;
	}

	public TreeNode(String id, String pid, String name, String type,
			String field, boolean isParent) {
		this.id = id;
		this.pid = pid;
		this.name = name;
		this.type = type;
		this.field = field;
		this.isParent = isParent;
	}

	public TreeNode copy() {
		TreeNode dest = new TreeNode();
		super.copyTo(dest);
		dest.setPid(pid);
		dest.setIsParent(isParent);
		dest.setNotclick(notclick);
		dest.setDynamic(dynamic);
		dest.setIconSkin(iconSkin);

		if (children != null) {
			List<TreeNode> clist = new ArrayList<TreeNode>();
			for (TreeNode node : children) {
				TreeNode cnode = node.copy();
				clist.add(cnode);
			}
			dest.setChildren(clist);
		}

		return dest;
	}

	public String getPid() {
		return pid;
	}

	public void setPid(String pid) {
		this.pid = pid;
	}

	public boolean isIsParent() {
		return isParent;
	}

	public void setIsParent(boolean isParent) {
		this.isParent = isParent;
	}

	public boolean isNotclick() {
		return notclick;
	}

	public void setNotclick(boolean notclick) {
		this.notclick = notclick;
	}

	public boolean isDynamic() {
		return dynamic;
	}

	public void setDynamic(boolean dynamic) {
		this.dynamic = dynamic;
	}

	public String getIconSkin() {
		return iconSkin;
	}

	public void setIconSkin(String iconSkin) {
		this.iconSkin = iconSkin;
	}

	public List<TreeNode> getChildren() {
		return children;
	}

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

	public void addChild(TreeNode node) {
		if (children == null) {
			children = new ArrayList<TreeNode>();
		}
		children.add(node);
		if (node.getPid() == null) {
			node.setPid(this.id);
		}
	}

}
</span>

<span style="font-family:KaiTi_GB2312;font-size:18px;">public abstract class BaseNode {
	protected String id;	//数据ID
	protected String name;	//名称
	protected String code;	//代码，用于权限过滤
	protected String type;	//tree：加载树；其他：数据类型
	protected String icon;	//图标
	protected String field;	//参数名
	protected String custattr = "";	//该参数不为空时会作为请求参数发送，由业务系统进行相关处理</span>

<span style="font-family:KaiTi_GB2312;font-size:18px;">	}</span>

总结：

部分代码已经实现，树型结构的实现其实挺简单的，就是用代码控制数据在界面上的展示的动作，后台代码具体的就是这些。