一个树型通用接口

时间：2022-04-18 22:32:41

　　项目中难免遇到使用树型结构，如部门、菜单等。

　　它们有共同的属性：id，name，parentId，因此抽象出一个接口，然后使用一个工具类实现列表转树的功能。

　　（其它这个是在另一个项目找到的，非原创，在此共享一下）

　　看源码：

　　1、树型结构接口TreeObject.java

import java.util.List;

/**
 * 这个是列表树形式显示的接口
*/
public interface TreeObject {

    Object getId();

void setId(Object id);

    Object getParentId();

void setParentId(Object parentId);

    String getName();

void setName(String name);

    List getChildren();

void setChildren(List children);

}

　　2、树型处理工具类TreeUtil.java

import org.apache.commons.lang3.StringUtils;

import java.util.*;

/**
 * 把一个list集合,里面的bean含有 parentId 转为树形式
 *
*/
public class TreeUtil {

/**
     * 判断两个父ID是否相同
     * @param p1
     * @param p2
     * @return
*/
private boolean isEqualsParentId(Object p1,Object p2){
if(p1!=null && p1!=null){
return p1.equals(p2);
        }else if(p1==null && p2 == null) {
return true;
        }else if(p1==null && p2 != null) {
if("".equals(p2.toString())){
return true;
            }else{
return false;
            }
        }else if(p1!=null && p2 == null) {
if("".equals(p1.toString())){
return true;
            }else{
return false;
            }
        }else{
return false;
        }
    }

/**
     * 根据父节点的ID获取所有子节点，该方法*节点必须为空
     * @param list 分类表
     * @param parentId 传入的父节点ID
     * @return String
*/
public List getChildTreeObjects(List<TreeObject> list,Object parentId) {
        List returnList = new ArrayList();
if(list!=null&&list.size()>0) {
for (Iterator<TreeObject> iterator = list.iterator(); iterator.hasNext(); ) {
                TreeObject t = (TreeObject) iterator.next();
// 一、根据传入的某个父节点ID,遍历该父节点的所有子节点
if (isEqualsParentId(t.getParentId(), parentId)) {
                    recursionFn(list, t);
                    returnList.add(t);
                }
            }
        }
return returnList;
    }

/**
     * 根据父节点的ID获取所有子节点，该方法*节点可以不为空,非树直接返回
     * @param list 分类表
     * @return String
*/
public List<TreeObject> getChildTreeObjects(List<TreeObject> list) {
if(list!=null&&list.size()>0) {
            List<TreeObject> topList=new ArrayList<>();
            List<TreeObject> subList=new ArrayList<>();

            Map<String,String> idMap=new HashMap<>();

for (Iterator<TreeObject> iterator = list.iterator(); iterator.hasNext(); ) {
//归并所有list的id集合
                TreeObject t = (TreeObject) iterator.next();
                idMap.put(t.getId().toString(), t.getId().toString());
            }

for (Iterator<TreeObject> iterator = list.iterator(); iterator.hasNext(); ) {
//获取最*的list
                TreeObject t = (TreeObject) iterator.next();
if(t.getParentId()==null|| StringUtils.isEmpty(t.getParentId().toString())){
                    topList.add(t);
                }else{
                    String id=idMap.get(t.getParentId().toString());
if(StringUtils.isEmpty(id)){
                        topList.add(t);
                    }else{
                        subList.add(t);
                    }
                }
            }
if(topList!=null&&topList.size()>0&&subList!=null&&subList.size()>0){
                List<TreeObject> resultList=new ArrayList<>();
for (TreeObject t:topList) {
//将儿子级别的list归并到*中
                    List<TreeObject> subOneList=new ArrayList<>();

for (TreeObject sub:subList) {
// 一、根据传入的某个父节点ID,遍历该父节点的所有子节点
if (isEqualsParentId(sub.getParentId(), t.getId())) {
                            recursionFn(subList, sub);
                            subOneList.add(sub);
                        }
                    }
                    t.setChildren(subOneList);


                    resultList.add(t);
                }
return resultList;
            }else{
return list;
            }
        }
return list;
    }


/**
     * 递归列表
     * @param list
     * @param t
*/
private void  recursionFn(List<TreeObject> list, TreeObject t) {
        List<TreeObject> childList = getChildList(list, t);// 得到子节点列表
        t.setChildren(childList);
for (TreeObject tChild : childList) {
if (hasChild(list, tChild)) {// 判断是否有子节点
//returnList.add(TreeObject);
                Iterator<TreeObject> it = childList.iterator();
while (it.hasNext()) {
                    TreeObject n = (TreeObject) it.next();
                    recursionFn(list, n);
                }
            }
        }
    }

// 得到子节点列表
private List<TreeObject> getChildList(List<TreeObject> list, TreeObject t) {

        List<TreeObject> tlist = new ArrayList<TreeObject>();
        Iterator<TreeObject> it = list.iterator();
while (it.hasNext()) {
            TreeObject n = (TreeObject) it.next();
if (isEqualsParentId(n.getParentId(),t.getId())) {
                tlist.add(n);
            }
        }
return tlist;
    } 
    List<TreeObject> returnList = new ArrayList<TreeObject>();
/**
     * 根据父节点的ID获取所有子节点
     * @param list 分类表
     * @param parentId 传入的父节点ID
     * @param prefix 子节点前缀
*/
public List<TreeObject> getChildTreeObjects(List<TreeObject> list, Object parentId,String prefix){
if(list == null) return null;
for (Iterator<TreeObject> iterator = list.iterator(); iterator.hasNext();) {
            TreeObject node = (TreeObject) iterator.next();
// 一、根据传入的某个父节点ID,遍历该父节点的所有子节点
if (isEqualsParentId(node.getParentId(),parentId)) {
                recursionFn(list, node,prefix);
            }
// 二、遍历所有的父节点下的所有子节点
/*if (node.getParentId()==0) {
                recursionFn(list, node);
            }*/
        }
return returnList;
    }

private void recursionFn(List<TreeObject> list, TreeObject node,String p) {
        List<TreeObject> childList = getChildList(list, node);// 得到子节点列表
if (hasChild(list, node)) {// 判断是否有子节点
            returnList.add(node);
            Iterator<TreeObject> it = childList.iterator();
while (it.hasNext()) {
                TreeObject n = (TreeObject) it.next();
                n.setName(p+n.getName());
                recursionFn(list, n,p+p);
            }
        } else {
            returnList.add(node);
        }
    }

// 判断是否有子节点
private boolean hasChild(List<TreeObject> list, TreeObject t) {
return getChildList(list, t).size() > 0 ? true : false;
    }

}

　　3、使用示例

　　以菜单为例，菜单对象实现TreeObject接口

　　（@ApiModel、@ApiModelProperty不需要的，是用于生成API文档的）

import com.mjwon.core.tree.TreeObject;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;

import java.io.Serializable;
import java.util.List;

@ApiModel(value = "菜单树对象")
public class MenuTreeDto implements Serializable, TreeObject {
private static final long serialVersionUID = 1L;
    @ApiModelProperty(value = "菜单ID", example = "1", required = true)
private String id;
    @ApiModelProperty(value = "菜单名称", example = "菜单", required = true)
private String menuName;
    @ApiModelProperty(value = "菜单类型", example = "1", required = true)
private Short menuType;
    @ApiModelProperty(value = "菜单代码", example = "1", required = true)
private String menuCode;
    @ApiModelProperty(value = "父节点ID", example = "2", required = true)
private String parentId;
    @ApiModelProperty(value = "排序", example = "2", required = false)
private Long sortNo;
    @ApiModelProperty(value = "展开状态", example = "1/0", required = true)
private Short expand;
    @ApiModelProperty(value = "是否为叶子", example = "0/1", required = true)
private Short isShow;
    @ApiModelProperty(value = "权限标识", example = "task.scheduled", required = true)
private String permission;
    @ApiModelProperty(value = "备注", example = "备注", required = false)
private String comt;
    @ApiModelProperty(value = "是否启用", example = "1/0", required = false)
private Short enable;
    @ApiModelProperty(value = "节点图标CSS类名", example = "fa fas", required = false)
private String iconcls;
    @ApiModelProperty(value = "请求地址", example = "app.syslog", required = false)
private String request;
    @ApiModelProperty(value = "子部门", example = "父节点", required = false)
private List children;

    @Override
public Object getId() {
return this.id;
    }

    @Override
public void setId(Object id) {
this.id = (String) id;
    }

    @Override
public Object getParentId() {
return this.parentId;
    }

    @Override
public void setParentId(Object parentId) {
this.parentId = (String) parentId;
    }

    @Override
public String getName() {
return this.menuName;
    }

    @Override
public void setName(String name) {
this.menuName = name;
    }

    @Override
public List getChildren() {
return this.children;
    }

    @Override
public void setChildren(List children) {
this.children = children;
    }

public void setId(String id) {
this.id = id;
    }

public String getMenuName() {
return menuName;
    }

public void setMenuName(String menuName) {
this.menuName = menuName;
    }

public Short getMenuType() {
return menuType;
    }

public void setMenuType(Short menuType) {
this.menuType = menuType;
    }

public void setParentId(String parentId) {
this.parentId = parentId;
    }

public Long getSortNo() {
return sortNo;
    }

public void setSortNo(Long sortNo) {
this.sortNo = sortNo;
    }

public Short getExpand() {
return expand;
    }

public void setExpand(Short expand) {
this.expand = expand;
    }

public Short getIsShow() {
return isShow;
    }

public void setIsShow(Short isShow) {
this.isShow = isShow;
    }

public String getPermission() {
return permission;
    }

public void setPermission(String permission) {
this.permission = permission;
    }

public String getComt() {
return comt;
    }

public void setComt(String comt) {
this.comt = comt;
    }

public Short getEnable() {
return enable;
    }

public void setEnable(Short enable) {
this.enable = enable;
    }

public String getIconcls() {
return iconcls;
    }

public void setIconcls(String iconcls) {
this.iconcls = iconcls;
    }

public String getRequest() {
return request;
    }

public void setRequest(String request) {
this.request = request;
    }

public String getMenuCode() {
return menuCode;
    }

public void setMenuCode(String menuCode) {
this.menuCode = menuCode;
    }
}

　　查询出菜单对的所有数据，然后转为树结构即可 

　　　　　List dtoList = BeanMapper.mapList(menuList,MenuTreeDto.class);
if(dtoList!=null && dtoList.size()>0) {
            TreeUtil treeUtil = new TreeUtil();
            List<MenuTreeDto> treeList = treeUtil.getChildTreeObjects(dtoList, parentId);
return treeList;
        }

 

  　　生成树的结构示例：菜单树JSON

一个树型通用接口一个树型通用接口
{
"success": true,
"message": "请求成功",
"data": [
        {
"id": "1",
"menuName": "系统管理",
"menuType": 1,
"menuCode": "sys",
"parentId": "0",
"sortNo": 50,
"expand": 0,
"isShow": 1,
"permission": "sys",
"comt": "test",
"enable": 1,
"iconcls": "fa fa-angle-right",
"request": "#",
"children": [
                {
"id": "16",
"menuName": "用户角色",
"menuType": 1,
"menuCode": "user.role",
"parentId": "1",
"sortNo": 11,
"expand": 0,
"isShow": 0,
"permission": "user.role",
"comt": null,
"enable": 1,
"iconcls": "fa fa-users",
"request": "app.sys.userroles",
"children": null,
"name": "用户角色"
                },
                {
"id": "17",
"menuName": "权限管理",
"menuType": 1,
"menuCode": "sys.access",
"parentId": "1",
"sortNo": 12,
"expand": 0,
"isShow": 1,
"permission": "sys.access",
"comt": null,
"enable": 1,
"iconcls": "fa fa-list",
"request": "app.sys.auth",
"children": null,
"name": "权限管理"
                },
                {
"id": "18",
"menuName": "系统日志",
"menuType": 1,
"menuCode": "sys.syslog",
"parentId": "1",
"sortNo": 22,
"expand": 1,
"isShow": 1,
"permission": "sys.syslog",
"comt": null,
"enable": 1,
"iconcls": "fa fa-list",
"request": "app.syslog",
"children": null,
"name": "系统日志"
                },
                {
"id": "19",
"menuName": "业务日志",
"menuType": 1,
"menuCode": "sys.log.business",
"parentId": "1",
"sortNo": 999,
"expand": 1,
"isShow": 1,
"permission": "sys.log.business",
"comt": null,
"enable": 1,
"iconcls": "fa fa-list",
"request": "app.businesslog",
"children": null,
"name": "业务日志"
                },
                {
"id": "2",
"menuName": "用户管理",
"menuType": 1,
"menuCode": "sys.user",
"parentId": "1",
"sortNo": 1,
"expand": 0,
"isShow": 1,
"permission": "sys.user",
"comt": null,
"enable": 1,
"iconcls": "fa fa-user",
"request": "app.user",
"children": null,
"name": "用户管理"
                },
                {
"id": "3",
"menuName": "部门管理",
"menuType": 1,
"menuCode": "sys.dept",
"parentId": "1",
"sortNo": 2,
"expand": 0,
"isShow": 1,
"permission": "sys.dept",
"comt": null,
"enable": 1,
"iconcls": "fa fa-users",
"request": "app.dept",
"children": null,
"name": "部门管理"
                },
                {
"id": "4",
"menuName": "菜单管理",
"menuType": 1,
"menuCode": "sys.menu",
"parentId": "1",
"sortNo": 3,
"expand": 0,
"isShow": 1,
"permission": "sys.menu",
"comt": null,
"enable": 1,
"iconcls": "fa fa-bars",
"request": "app.menu",
"children": null,
"name": "菜单管理"
                },
                {
"id": "5",
"menuName": "角色管理",
"menuType": 1,
"menuCode": "sys.role",
"parentId": "1",
"sortNo": 4,
"expand": 0,
"isShow": 1,
"permission": "sys.role",
"comt": null,
"enable": 1,
"iconcls": "fa fa-cog",
"request": "app.role",
"children": null,
"name": "角色管理"
                },
                {
"id": "6",
"menuName": "会话管理",
"menuType": 1,
"menuCode": "sys.session",
"parentId": "1",
"sortNo": 6,
"expand": 0,
"isShow": 0,
"permission": "sys.session",
"comt": null,
"enable": 1,
"iconcls": "fa fa-list",
"request": "main.sys.session.list",
"children": null,
"name": "会话管理"
                },
                {
"id": "7",
"menuName": "字典管理",
"menuType": 1,
"menuCode": "sys.dic",
"parentId": "1",
"sortNo": 7,
"expand": 0,
"isShow": 1,
"permission": "sys.dic",
"comt": null,
"enable": 1,
"iconcls": "fa fa-book",
"request": "app.dictindex",
"children": null,
"name": "字典管理"
                },
                {
"id": "8",
"menuName": "业务参数",
"menuType": 1,
"menuCode": "sys.param",
"parentId": "1",
"sortNo": 8,
"expand": 0,
"isShow": 0,
"permission": "sys.param",
"comt": null,
"enable": 1,
"iconcls": "fa fa-wrench",
"request": "main.sys.param.list",
"children": null,
"name": "业务参数"
                },
                {
"id": "20",
"menuName": "数据权限",
"menuType": 1,
"menuCode": "sys.dataauth",
"parentId": "1",
"sortNo": 20,
"expand": 1,
"isShow": 1,
"permission": "sys.dataauth",
"comt": null,
"enable": 1,
"iconcls": "fa fa-users",
"request": "app.dataauth",
"children": null,
"name": "数据权限"
                }
            ],
"name": "系统管理"
        },
        {
"id": "9",
"menuName": "调度中心",
"menuType": 1,
"menuCode": "task",
"parentId": "0",
"sortNo": 2,
"expand": 0,
"isShow": 0,
"permission": "task",
"comt": null,
"enable": 1,
"iconcls": "fa fa-angle-right",
"request": "#",
"children": [
                {
"id": "10",
"menuName": "任务组管理",
"menuType": 1,
"menuCode": "task.group",
"parentId": "9",
"sortNo": 1,
"expand": 0,
"isShow": 0,
"permission": "task.group",
"comt": null,
"enable": 1,
"iconcls": "fa fa-tasks",
"request": "main.task.group.list",
"children": null,
"name": "任务组管理"
                },
                {
"id": "11",
"menuName": "任务管理",
"menuType": 1,
"menuCode": "task.scheduler",
"parentId": "9",
"sortNo": 2,
"expand": 0,
"isShow": 0,
"permission": "task.scheduler",
"comt": null,
"enable": 1,
"iconcls": "fa fa-table",
"request": "main.task.scheduler.list",
"children": null,
"name": "任务管理"
                },
                {
"id": "12",
"menuName": "调度管理",
"menuType": 1,
"menuCode": "task.scheduled",
"parentId": "9",
"sortNo": 3,
"expand": 0,
"isShow": 0,
"permission": "task.scheduled",
"comt": null,
"enable": 1,
"iconcls": "fa fa-user",
"request": "main.task.scheduled.list",
"children": null,
"name": "调度管理"
                },
                {
"id": "13",
"menuName": "调度日志",
"menuType": 1,
"menuCode": "task.log",
"parentId": "9",
"sortNo": 4,
"expand": 0,
"isShow": 0,
"permission": "task.log",
"comt": null,
"enable": 1,
"iconcls": "fa fa-list",
"request": "main.task.log.list",
"children": null,
"name": "调度日志"
                },
                {
"id": "15",
"menuName": "角色权限",
"menuType": 1,
"menuCode": "role.access",
"parentId": "9",
"sortNo": 11,
"expand": 1,
"isShow": 1,
"permission": "role.access",
"comt": null,
"enable": 1,
"iconcls": "fa fa-list",
"request": "app.sys.roleaccess",
"children": null,
"name": "角色权限"
                }
            ],
"name": "调度中心"
        }
    ]
}
View Code

 　　至此，可以方便实现树结构JSON的返回。over.

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