Layui之动态树

一，分析左侧树形菜单

二，获取表中的数据

三，将表中的数据构建父子关系

四，前端代码

一，分析左侧树形菜单

我们需要将如下数据展示在动态树当中

表名：t_oa_permission

从layui中得到的动态树模型代码

main.jsp页面代码展示：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%@ include file="common/head.jsp" %>




Insert title here



  
    layout demo
    
    
      
      
        
      
      
      nav 1
      nav 2
      nav 3
      
        nav groups
        
          menu 11
          menu 22
          menu 33
        
      
    
    
    
      
        
          
          tester
        
        
          Your Profile
          Settings
          Sign out
        
      
      
        
          
        
      
    
  
  
  
    
      
      
         
          menu group 1
          
            menu 1
            menu 2
            menu 3
            the links
          
        
        
          menu group 2
          
            list 1
            list 2
            超链接
          
        
        click menu item
        the links
      
    
  
  
  
    
    内容主体区域。记得修改 layui.css 和 js 的路径
  
  
  
    
            底部固定区域

动态树页面效果展示：

二，获取表中的数据

将t_oa_permission表中的列名编写在实体类当中，在数据库中使用指令desc * from 表名查看表结构以此判断列名的数据类型

注意：数据类型需要保持一致，否则无效

创建实体类Permission：

package com.zking.entity;

//数据库中t_oa_Permission表对应的实体类
public class Permission {
	private long id;//id
	private String name;//菜单名
	private String description;//菜单描述
	private String url;//点击菜单跳转页面
	private long pid;//父级菜单的id
	private int ismenu;//显示顺序
	private long displayno;//显示的顺序
	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() {
		// TODO Auto-generated constructor stub
	}
	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;
	}
	@Override
	public String toString() {
		return "Permission [id=" + id + ", name=" + name + ", description=" + description + ", url=" + url + ", pid="
				+ pid + ", ismenu=" + ismenu + ", displayno=" + displayno + "]";
	}
	
	
}

PermissionDao方法

package com.zking.dao;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import com.zking.entity.Permission;
import com.zking.util.BaseDao;
import com.zking.util.BuildTree;
import com.zking.util.PageBean;
import com.zking.util.TreeVo;

public class permissionDao extends BaseDao{
	
	//查询t_oa_permission表中的数据
	public List list(Permission permission, PageBean pageBean) throws Exception {
		String sql = "select * from t_ao_permission";
		return super.executeQuery(sql, Permission.class, pageBean);
	}
	
	public List> menus(Permission permission, PageBean pageBean) throws Exception {
		List> trees = new ArrayList>();
		//从数据库拿到的菜单数据，此时数据是平级的，不具备父子关系
		List list = this.list(permission, pageBean);
		for (Permission p : list) {
			TreeVo vo = new TreeVo<>();
			vo.setId(p.getId()+"");
			vo.setText(p.getName());
			vo.setParentId(p.getPid()+"");//节点的父id
			trees.add(vo);
		}
		return BuildTree.buildList(trees, "-1");
	}
	
	
	
}

permissionDaoTest 测试

package com.zking.dao;

import static org.junit.jupiter.api.Assertions.*;

import java.util.List;

import org.junit.jupiter.api.Test;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.zking.entity.Permission;
import com.zking.util.TreeVo;

class PermissionDaoTest {
	
	private PermissionDao menudao =new PermissionDao();

	@Test
	void testList() {
		try {
			List list = menudao.list(null, null);
			for (Permission permission : list) {
				System.out.println(permission);
			}
			ObjectMapper om = new ObjectMapper();
			System.out.println(om.writeValueAsString(list));
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	@Test
	void testMenus() {
		try {
			List> list = menudao.menus(null, null);
			for (TreeVo permission: list) {
				System.out.println(permission);
			}
			ObjectMapper om = new ObjectMapper();
			System.out.println(om.writeValueAsString(list));
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

测试testlist方法：

测试testMenus方法：

三，将表中的数据构建父子关系

BuildTree类：

package com.zking.util;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class BuildTree {

	
	public static  TreeVo build(List> nodes) {

		if (nodes == null) {
			return null;
		}
		List> topNodes = new ArrayList>();

		for (TreeVo children : nodes) {
			String pid = children.getParentId();
			if (pid == null || "-1".equals(pid)) {
				topNodes.add(children);

				continue;
			}

			for (TreeVo parent : nodes) {
				String id = parent.getId();
				if (id != null && id.equals(pid)) {
					parent.getChildren().add(children);
					children.setHasParent(true);
					parent.setChildren(true);
					continue;
				}
			}

		}

		TreeVo root = new TreeVo();
		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 state = new HashMap<>(16);
			state.put("opened", true);
			root.setState(state);
		}

		return root;
	}

	
	public static  List> buildList(List> nodes, String idParam) {
		if (nodes == null) {
			return null;
		}
		List> topNodes = new ArrayList>();

		for (TreeVo children : nodes) {

			String pid = children.getParentId();
			if (pid == null || idParam.equals(pid)) {
				topNodes.add(children);

				continue;
			}

			for (TreeVo 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;
	}

}

Treevo实体类：

package com.zking.util;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;


public class TreeVo {
	
	private String id;
	
	private String text;
	
	private Map state;
	
	private boolean checked = false;
	
	private Map attributes;

	
	private List> children = new ArrayList>();

	
	private String parentId;
	
	private boolean hasParent = false;
	
	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 getState() {
		return state;
	}

	public void setState(Map state) {
		this.state = state;
	}

	public boolean isChecked() {
		return checked;
	}

	public void setChecked(boolean checked) {
		this.checked = checked;
	}

	public Map getAttributes() {
		return attributes;
	}

	public void setAttributes(Map attributes) {
		this.attributes = attributes;
	}

	public List> getChildren() {
		return children;
	}

	public void setChildren(List> 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 state, boolean checked, Map attributes,
                  List> 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();
	}

}

permissionDao

package com.zking.dao;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import com.zking.entity.Permission;
import com.zking.util.BaseDao;
import com.zking.util.BuildTree;
import com.zking.util.PageBean;
import com.zking.util.TreeVo;

public class permissionDao extends BaseDao{
	public List> menus(Permission permission, PageBean pageBean) throws Exception {
		List> trees = new ArrayList>();
		//从数据库拿到的菜单数据，此时数据是平级的，不具备父子关系
		List list = this.list(permission, pageBean);
		for (Permission p : list) {
			TreeVo vo = new TreeVo<>();
			vo.setId(p.getId()+"");
			vo.setText(p.getName());
			vo.setParentId(p.getPid()+"");//节点的父id
			trees.add(vo);
		}
		return BuildTree.buildList(trees, "-1");
	}
}

四、前端代码

建立一个PermissionAction：

package com.zking.web;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.zking.dao.permissionDao;
import com.zking.entity.Permission;
import com.zking.framework.ActionSupport;
import com.zking.framework.ModelDriver;
import com.zking.util.ResponseUtil;
import com.zking.util.TreeVo;

public class PermissionAction extends ActionSupport implements ModelDriver{

	private Permission permission = new Permission();
	permissionDao permissiondao = new permissionDao();
	@Override
	public Permission getModel() {
		return permission;
	}
	
	
	public String menus(HttpServletRequest req, HttpServletResponse resp) {
		try {
			List> menus = permissiondao.menus(null, null);
			//向前端响应数据
			ResponseUtil.writeJson(resp, menus);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

}

修改main界面（主界面）：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%@ include file="common/head.jsp" %>




Insert title here



  
    layout demo
    
    
      
      
        
      
      
      nav 1
      nav 2
      nav 3
      
        nav groups
        
          menu 11
          menu 22
          menu 33
        
      
    
    
    
      
        
          
          tester
        
        
          Your Profile
          Settings
          Sign out
        
      
      
        
          
        
      
    
  
  
  
    
      
      
         
          menu group 1
          
            menu 1
            menu 2
            menu 3
            the links
          
        
        
          menu group 2
          
            list 1
            list 2
            超链接
          
        
        click menu item
        the links
      
    
  
  
  
    
    内容主体区域。记得修改 layui.css 和 js 的路径
  
  
  
    
            底部固定区域

最终结果：

下一期我们将对本期内容进行巩固，切换一张数据表来进行同样的展示若本期内容有误或者不足还望指出！

Layui之动态树

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