递归遍历部门树

遍历方法：

public class SysTest {
    /**
     * 构建前端所需要树结构
     *
     * @param depts 部门列表
     * @return 树结构列表
     */
    public List<SysDept> buildDeptTree(List<SysDept> depts)
    {
        List<SysDept> returnList = new ArrayList<SysDept>();
        List<Long> tempList = new ArrayList<Long>();
        for (SysDept dept : depts)
        {
            tempList.add(dept.getDeptId());
        }
        for (Iterator<SysDept> iterator = depts.iterator(); iterator.hasNext();)
        {
            SysDept dept = (SysDept) iterator.next();
            // 如果是顶级节点, 遍历该父节点的所有子节点
            if (!tempList.contains(dept.getParentId()))
            {
                recursionFn(depts, dept);
                returnList.add(dept);
            }
        }
        if (returnList.isEmpty())
        {
            returnList = depts;
        }
        return returnList;
    }

    /**
     * 递归列表
     */
    private void recursionFn(List<SysDept> list, SysDept t)
    {
        // 得到子节点列表
        List<SysDept> childList = getChildList(list, t);
        t.setChildren(childList);
        for (SysDept tChild : childList)
        {
            if (hasChild(list, tChild))
            {
                recursionFn(list, tChild);
            }
        }
    }

    /**
     * 得到子节点列表
     */
    private List<SysDept> getChildList(List<SysDept> list, SysDept t)
    {
        List<SysDept> tlist = new ArrayList<SysDept>();
        Iterator<SysDept> it = list.iterator();
        while (it.hasNext())
        {
            SysDept n = (SysDept) it.next();
            if (StringUtils.isNotNull(n.getParentId()) && n.getParentId().longValue() == t.getDeptId().longValue())
            {
                tlist.add(n);
            }
        }
        return tlist;
    }

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

调用及lambda表达式处理：

    public List<TreeSelect> buildDeptTreeSelect(List<SysDept> depts)
    {
        List<SysDept> deptTrees = buildDeptTree(depts);
        return deptTrees.stream().map(TreeSelect::new).collect(Collectors.toList());
    }

树的实体类：

package com.ruoyi.common.core.domain;

import java.io.Serializable;
import java.util.List;
import java.util.stream.Collectors;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.ruoyi.common.core.domain.entity.SysDept;
import com.ruoyi.common.core.domain.entity.SysMenu;

/**
 * Treeselect树结构实体类
 * 
 * @author ruoyi
 */
public class TreeSelect implements Serializable
{
    private static final long serialVersionUID = 1L;

    /** 节点ID */
    private Long id;

    /** 节点名称 */
    private String label;

    /** 子节点 */
    @JsonInclude(JsonInclude.Include.NON_EMPTY)
    private List<TreeSelect> children;

    public TreeSelect()
    {

    }

    public TreeSelect(SysDept dept)
    {
        this.id = dept.getDeptId();
        this.label = dept.getDeptName();
        this.children = dept.getChildren().stream().map(TreeSelect::new).collect(Collectors.toList());
    }

    public TreeSelect(SysMenu menu)
    {
        this.id = menu.getMenuId();
        this.label = menu.getMenuName();
        this.children = menu.getChildren().stream().map(TreeSelect::new).collect(Collectors.toList());
    }

    public Long getId()
    {
        return id;
    }

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

    public String getLabel()
    {
        return label;
    }

    public void setLabel(String label)
    {
        this.label = label;
    }

    public List<TreeSelect> getChildren()
    {
        return children;
    }

    public void setChildren(List<TreeSelect> children)
    {
        this.children = children;
    }
}