树的生成（Lambda表达式写法）

1.Controller：

//查询树
@PostMapping("/list")
public List<TbBasetree> list(@RequestBody Map<String,String> param) {
    String mark = param.get("mark");
    List<TbBasetree> personList = tbBasetreeService.getPersonList(mark);
    return personList;
}

2.Service:

List<TbBasetree> getPersonList(String mark);

3.ServiceImpl:

在查询树的基础上添加需求：
1、根据mark查询树，该字段对应数据库的info_mark字段，0表示设备类型，1表示车站类型，且默认查询设备类型。
2、只有基础类被选中。

    @Override
    public List<TbBasetree> getPersonList(String mark) {
        List<TbBasetree> allList = null;
        if("0".equals(mark) || mark == null) {
            allList = tbBasetreeMapper.getPersonList(mark);
        }else if("1".equals(mark)) {
            allList = tbBasetreeMapper.getPersonList2(mark);
        }

        //查询所有的数据
//        List<TbBasetree> allList = tbBasetreeMapper.getPersonList(mark);
        List<TbBasetree> finalAllList = allList;
        return allList.stream().filter(item -> "0".equals(item.getParentId())).map(item -> {
            item.setChildren(getChild(item.getId(), finalAllList, ""));
            //虚拟字段spread为true时表示默认展开
            item.setSpread("true");
            //虚拟字段checked为true时表示默认选中
            item.setChecked("true");
            return item;
        }).collect(Collectors.toList());
    }

    String baseId = "";
    private List<TbBasetree> getChild(String id,List<TbBasetree> allList,String checkedPid) {
        return allList.stream().filter(item -> id.equals(item.getParentId()
        )).map(item -> {
            if ("基础类".equals(item.getTitle())){
                baseId = item.getId();
                item.setChecked("true");
                item.setChildren(getChild(item.getId(), allList,checkedPid));
            }else if (baseId.equals(item.getParentId()) || (!"".equals(checkedPid) && checkedPid.equals(item.getParentId()))) {
                item.setChecked("true");
                item.setChildren(getChild(item.getId(), allList,item.getId()));
            }else{
                item.setChildren(getChild(item.getId(), allList,checkedPid));
            }
            return item;
        }).collect(Collectors.toList());
    }


旧版+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

@Override
public List<TbBasetree> getTreeState() {
    //查询所有的数据
    List<TbBasetree> allList = tbBasetreeMapper.getTreeState();
    //创建一个list集合，用于存放根节点
    List<TbBasetree> parent = new ArrayList<>();
    for (TbBasetree person : allList) {
        //如果parentId为0，则代表是根节点，存入到集合中         person.setSpread(true);  自动展开
        if (person.getParentId().equals("0")) {
            //虚拟字段spread为true时表示默认展开
            person.setSpread("true");
            //虚拟字段checked为true时表示默认选中
            person.setChecked("true");
            parent.add(person);
        }
    }
    //查找根节点下的子类，因为根节点的id就是子节点的parentId;
    for (TbBasetree person : parent) {
        List<TbBasetree> children = getChild2(person.getId(), allList);
        person.setChildren(children);
    }
    return parent;
}

//查找子节点的方法
private List<TbBasetree> getChild2(String id, List<TbBasetree> allList) {
    //存放子节点的集合
    List<TbBasetree> children = new ArrayList<>();
    for (TbBasetree person : allList) {
        //如果根节点的id等于集合内parentId,说明是根节点的子节点
        if (person.getParentId().equals(id)) {
            //存入子节点集合
            //虚拟字段checked为true时表示默认选中
            person.setChecked("true");
            children.add(person);
        }
    }
    for (TbBasetree person : children) {
        //递归调用，如果子节点存在根节点，则再次调用，往后依次推
        List<TbBasetree> personChildren = getChild2(person.getId(), allList);
        person.setChildren(personChildren);
    }
    return children;
}

旧版+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

4.Mapper:

 

5.Mapper.xml: