Java生成Tree数据格式工具

• • 一、定义ITree接口
  • 二、继承ITree接口并实现方法
  • 三、工具类编写
  • 四、工具类调用

public interface ITree {

    
    Integer getId();

    
    Integer getParentId();

    
    List getChildren();

    
    void setChildren(List children);
}

@Data
public class MenusVo implements ITree {
    
    private Integer id;

    
    private String authName;

    
    private String path;

    
    private Integer parentId;

    
    private List children;
}

public class ConvertUtil {

    private ConvertUtil() {
    }

	
    public static  List convertTree(List resource, Predicate predicate) {
        List result = resource.stream().filter(predicate).collect(Collectors.toList());
        // 移出父级元素
        resource.removeIf(result::contains);
        ConvertUtil.setChilder(result, resource);
        return result;
    }

    
    private static  void setChilder(List parentList, List elements) {
        if (CollUtil.isEmpty(elements)) {
            return;
        }
        // 遍历父级
        parentList.forEach(parent -> {
            List childer = elements.stream().filter(element -> parent.getId().equals(element.getParentId())).collect(Collectors.toList());
            parent.setChildren(childer);
            elements.removeIf(childer::contains);
            setChilder(childer, elements);
        });
    }
}

public ResponseEntity tree() {
	List menusList = ConvertUtil.convertList(menusService.list(null), MenusVo.class);
    List result = ConvertUtil.convertTree(menusList, menusVo -> 0 == menusVo.getParentId());
}