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 })@ResponseBodypublic 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 })@ResponseBodypublic 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IDprivate 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CSSprivate 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IDprotected 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。