Tree组件

1、主题：将MySQL中的数据转入Tree组件
2、准备工作：
在WebContent下新建一些文件夹（Folder）
导入所需的资料

$(function(){$('#tt').tree({url:'tree_data1.json'});
})

然后根据数据库表中的字段名来写实体类

entity：

package com.xieying.entity;/**** @author 莹酱**/
public class Permission {private long id;private String name;private String description;private String url;private long pid;private int ismenu;private long displayno;public long getId() {return id;}public void setId(long id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getDescription() {return description;}public void setDescription(String description) {this.description = description;}public String getUrl() {return url;}public void setUrl(String url) {this.url = url;}public long getPid() {return pid;}public void setPid(long pid) {this.pid = pid;}public int getIsmenu() {return ismenu;}public void setIsmenu(int ismenu) {this.ismenu = ismenu;}public long getDisplayno() {return displayno;}public void setDisplayno(long displayno) {this.displayno = displayno;}public Permission(long id, String name, String description, String url, long pid, int ismenu, long displayno) {super();this.id = id;this.name = name;this.description = description;this.url = url;this.pid = pid;this.ismenu = ismenu;this.displayno = displayno;}public Permission() {super();}@Overridepublic String toString() {return "Permission [id=" + id + ", name=" + name + ", description=" + description + ", url=" + url + ", pid="+ pid + ", ismenu=" + ismenu + ", displayno=" + displayno + "]";}}

VO包—Treevo

package com.xieying.vo;import java.util.ArrayList;
import java.util.List;
import java.util.Map;/*** * @author 莹酱** @param <T>*/
public class TreeVo<T> {/*** 节点ID*/private String id;/*** 显示节点文本*/private String text;/*** 节点状态，open closed*/private Map<String, Object> state;/*** 节点是否被选中 true false*/private boolean checked = false;/*** 节点属性*/private Map<String, Object> attributes;/*** 节点的子节点*/private List<TreeVo<T>> children = new ArrayList<TreeVo<T>>();/*** 父ID*/private String parentId;/*** 是否有父节点*/private boolean hasParent = false;/*** 是否有子节点*/private boolean hasChildren = false;public String getId() {return id;}public void setId(String id) {this.id = id;}public String getText() {return text;}public void setText(String text) {this.text = text;}public Map<String, Object> getState() {return state;}public void setState(Map<String, Object> state) {this.state = state;}public boolean isChecked() {return checked;}public void setChecked(boolean checked) {this.checked = checked;}public Map<String, Object> getAttributes() {return attributes;}public void setAttributes(Map<String, Object> attributes) {this.attributes = attributes;}public List<TreeVo<T>> getChildren() {return children;}public void setChildren(List<TreeVo<T>> children) {this.children = children;}public boolean isHasParent() {return hasParent;}public void setHasParent(boolean isParent) {this.hasParent = isParent;}public boolean isHasChildren() {return hasChildren;}public void setChildren(boolean isChildren) {this.hasChildren = isChildren;}public String getParentId() {return parentId;}public void setParentId(String parentId) {this.parentId = parentId;}public TreeVo(String id, String text, Map<String, Object> state, boolean checked, Map<String, Object> attributes,List<TreeVo<T>> children, boolean isParent, boolean isChildren, String parentID) {super();this.id = id;this.text = text;this.state = state;this.checked = checked;this.attributes = attributes;this.children = children;this.hasParent = isParent;this.hasChildren = isChildren;this.parentId = parentID;}public TreeVo() {super();}}

dao方法—PemissionDao

package com.xieying.dao;import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import com.fasterxml.jackson.databind.ObjectMapper;
import com.xieying.entity.Permission;
import com.xieying.util.BaseDao;
import com.xieying.util.BuildTree;
import com.xieying.util.PageBean;
import com.xieying.vo.TreeVo;/*** * @author 莹酱**/
public class PemissionDao extends BaseDao<Permission> {public List<Permission> list(Permission permission,PageBean pageBean) throws IllegalAccessException, SQLException, Exception{String sql="select * from t_easyui_permission";return super.executeQuery(sql, Permission.class, pageBean);}public static void main(String[] args) throws IllegalAccessException, SQLException, Exception {Permission ps=new Permission();PemissionDao pd=new PemissionDao();List<Permission> list = pd.list(null, null);//通过工具类完成指定格式输出List<TreeVo<Permission>> nodes=new ArrayList<TreeVo<Permission>>();//permission的格式是不满足easyui的tree组件的展示的数据格式//目的将list<permission>转换为LIst(Treevo<T>)//实现：将List<Permission>得到的单个Permission转换为TreeVo，将Treevo加入到nodesTreeVo treevo=null;for (Permission pp : list) {treevo=new TreeVo<>();treevo.setId(pp.getId()+"");treevo.setText(pp.getName());treevo.setParentId(pp.getPid()+"");/*Map<String, Object> attributes=new HashMap<String, Object>();attributes.put("self", pp);treevo.setAttributes(attributes);*/nodes.add(treevo);}TreeVo<Permission> parent=BuildTree.build(nodes);ObjectMapper om=new ObjectMapper();String jsonstr = om.writeValueAsString(parent);System.out.println(jsonstr);}}

BuildTree

package com.xieying.util;import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import com.xieying.vo.TreeVo;public class BuildTree {/*** 默认-1为顶级节点* @param nodes* @param <T>* @return*/public static <T> TreeVo<T> build(List<TreeVo<T>> nodes) {if (nodes == null) {return null;}//存放顶级节点的容器List<TreeVo<T>> topNodes = new ArrayList<TreeVo<T>>();for (TreeVo<T> children : nodes) {String pid = children.getParentId();if (pid == null || "0".equals(pid)) {topNodes.add(children);//如果是顶级节点接收点前循环，继续下一次循环continue;}for (TreeVo<T> parent : nodes) {String id = parent.getId();if (id != null && id.equals(pid)) {parent.getChildren().add(children);children.setHasParent(true);parent.setChildren(true);continue;}}}//考虑到到一个问题数据库表中没有顶级节点TreeVo<T> root = new TreeVo<T>();if (topNodes.size() == 1) {root = topNodes.get(0);} else {root.setId("000");root.setParentId("-1");root.setHasParent(false);root.setChildren(true);root.setChecked(true);root.setChildren(topNodes);root.setText("顶级节点");Map<String, Object> state = new HashMap<>(16);state.put("opened", true);root.setState(state);}return root;}/*** 指定idparam为顶级节点* @param nodes* @param idParam* @param <T>* @return*/public static <T> List<TreeVo<T>> buildList(List<TreeVo<T>> nodes, String idParam) {if (nodes == null) {return null;}List<TreeVo<T>> topNodes = new ArrayList<TreeVo<T>>();for (TreeVo<T> children : nodes) {String pid = children.getParentId();if (pid == null || idParam.equals(pid)) {topNodes.add(children);continue;}for (TreeVo<T> parent : nodes) {String id = parent.getId();if (id != null && id.equals(pid)) {parent.getChildren().add(children);children.setHasParent(true);parent.setChildren(true);continue;}}}return topNodes;}}

接收到的JSON格式：

然后我们去官网格式化，效果如下：

后台代码就这些啦，白拜