layui三级菜单（动态树）
目录
一，分析
二，后台数据处理
1.util包
2.entity实体类
3.dao方法
4.web层
5.xml配置
三，前台处理
一，分析
这里是一个三级菜单id为15而且pid所对应的-1是父级目录，父级目录下有两个子目录：
想要的效果图 三层关系
二，后台数据处理
1.util包
连接数据库文件：
#mysql8
driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/t280?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT&useSSL=true
user=root
pwd=123456DBAccess：
package com.zking.util;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
/**
* 提供了一组获得或关闭数据库对象的方法
*
*/
public class DBAccess {
private static String driver;
private static String url;
private static String user;
private static String password;
static {// 静态块执行一次，加载 驱动一次
try {
InputStream is = DBAccess.class
.getResourceAsStream("config.properties");
Properties properties = new Properties();
properties.load(is);
driver = properties.getProperty("driver");
url = properties.getProperty("url");
user = properties.getProperty("user");
password = properties.getProperty("pwd");
Class.forName(driver);
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
/**
* 获得数据连接对象
*
* @return
*/
public static Connection getConnection() {
try {
Connection conn = DriverManager.getConnection(url, user, password);
return conn;
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
public static void close(ResultSet rs) {
if (null != rs) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
}
public static void close(Statement stmt) {
if (null != stmt) {
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
}
public static void close(Connection conn) {
if (null != conn) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
}
public static void close(Connection conn, Statement stmt, ResultSet rs) {
close(rs);
close(stmt);
close(conn);
}
public static boolean isOracle() {
return "oracle.jdbc.driver.OracleDriver".equals(driver);
}
public static boolean isSQLServer() {
return "com.microsoft.sqlserver.jdbc.SQLServerDriver".equals(driver);
}
public static boolean isMysql() {
return "com.mysql.cj.jdbc.Driver".equals(driver);
}
public static void main(String[] args) {
Connection conn = DBAccess.getConnection();
System.out.println(conn);
DBAccess.close(conn);
System.out.println("isOracle：" + isOracle());
System.out.println("isSQLServer：" + isSQLServer());
System.out.println("isMysql：" + isMysql());
System.out.println("数据库连接(关闭)成功");
}
}
BuildTree:
package com.zking.util;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class BuildTree {
/**
* 默认-1为顶级节点
* @param nodes
* @param
* @return
*/
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;
}
/**
* 指定idparam为顶级节点
* @param nodes
* @param idParam
* @param
* @return
*/
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:
package com.zking.util;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
public class TreeVo {
/**
* 节点ID
*/
private String id;
/**
* 显示节点文本
*/
private String text;
/**
* 节点状态，open closed
*/
private Map state;
/**
* 节点是否被选中 true false
*/
private boolean checked = false;
/**
* 节点属性
*/
private Map attributes;
/**
* 节点的子节点
*/
private List> children = new ArrayList>();
/**
* 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 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();
}
} 2.entity实体类
构建的实体类要与表中的字段名保持一致
package com.zking.entity;
//数据库中t_oa_permission对应的实体类
public class Permission {
private long id;
private String name;//菜单名
private String description;//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;//菜单/按钮
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() {
}
public Permission(long id, String name, String description, String url, long pid, int ismenu, long displayno) {
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 "PermissionDao [id=" + id + ", name=" + name + ", description=" + description + ", url=" + url + ", pid="
+ pid + ", ismenu=" + ismenu + ", displayno=" + displayno + "]";
}
}
3.dao方法
package com.zking.dao;
import java.util.ArrayList;
import java.util.List;
import com.zking.entity.Shop;
import com.zking.util.BaseDao;
import com.zking.util.BuildTree;
import com.zking.util.PageBean;
import com.zking.util.TreeVo;
public class ShopDao extends BaseDao{
//查询t_oa_permission表中的数据
public List list(Shop shop,PageBean pageBean) throws Exception{
String sql = "select * from t_easyui_permission";
return super.executeQuery(sql, Shop.class, pageBean);
}
public List> menus(Shop shop,PageBean pageBean) throws Exception{
List> trees = new ArrayList>();
//从数据库中拿到的菜单数据，此时数据是平级的，不具备父子关系
List list = this.list(shop, pageBean);
for (Shop s : list) {
TreeVo vo = new TreeVo<>();
vo.setId(s.getId()+"");
vo.setText(s.getName());//节点名称
vo.setParentId(s.getPid()+"");
trees.add(vo);
}
return BuildTree.buildList(trees, "0");
}
//三级目录
public TreeVo menu(Shop shop,PageBean pageBean) throws Exception{
List> trees = new ArrayList>();
//从数据库中拿到的菜单数据，此时数据是平级的，不具备父子关系
List list = this.list(shop, pageBean);
for (Shop s : list) {
TreeVo vo = new TreeVo<>();
vo.setId(s.getId()+"");
vo.setText(s.getName());//节点名称
vo.setParentId(s.getPid()+"");
trees.add(vo);
}
return BuildTree.build(trees);
}
}
可以测试一下：
test测试：
package com.zking.dao;
import static org.junit.Assert.*;
import java.util.List;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.zking.entity.Shop;
import com.zking.util.TreeVo;
public class ShopDaoTest {
private ShopDao shopDao = new ShopDao();
@Before
public void setUp() throws Exception{
}
@After
public void tearDown() throws Exception{
}
@Test
public void testList() {
try {
List list = shopDao.list(null, null);
for (Shop 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();
}
// fail("Not yet implemented");
}
@Test
public void testMenus() {
try {
List> list = shopDao.menus(null, null);
for (TreeVo Permission : list) {
System.out.println(Permission);
}
ObjectMapper om = new ObjectMapper();
System.out.println(om.writeValueAsString(list));
} catch (Exception e) {
e.printStackTrace();
}
}
}
4.web层
package com.zking.web;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.zking.dao.ShopDao;
import com.zking.entity.Shop;
import com.zking.framework.ActionSupport;
import com.zking.framework.ModelDriver;
import com.zking.util.ResponseUtil;
import com.zking.util.TreeVo;
public class ShopAction extends ActionSupport implements ModelDriver{
private Shop shop = new Shop();
private ShopDao shopDao = new ShopDao();
@Override
public Shop getModel() {
// TODO Auto-generated method stub
return shop;
}
public String menus(HttpServletRequest req,HttpServletResponse resp) {
try {
List> menus = shopDao.menus(null,null);
//向前端响应树形结构的数据
ResponseUtil.writeJson(resp, menus);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public String menu(HttpServletRequest req,HttpServletResponse resp) {
try {
TreeVo menu = shopDao.menu(null,null);
System.out.println(menu);
//向前端响应树形结构的数据
ResponseUtil.writeJson(resp, menu);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}
5.xml配置
配置一个路径：
三，前台处理
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@include file="commom/header.jsp" %>
Insert title here
效果图：
