JAVA8遍历tree

1.数据库表

1. 代码

2.1
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.List;

/** 字典树
*/
@Data
@Builder
@NoArgsConstructor
//@AllArgsConstructor
public class DictDataVo {
private int id;
private int idP;
private String dictLabel;
private String dictValue;
private String dictType;
private List childList;

public DictDataVo(int id, int idP, String dictLabel, String dictValue, String dictType){
    this.id = id;
    this.idP = idP;
    this.dictLabel = dictLabel;
    this.dictValue = dictValue;
}

public DictDataVo(int id, int idP, String dictLabel, String dictValue, String dictType, List<DictDataVo> childList){
    this.id = id;
    this.idP = idP;
    this.dictLabel = dictLabel;
    this.dictValue = dictValue;
    this.childList = childList;
}

}
2.2 实现

/****
 * 字典树
 * @param dictType
 * @return
 */
@Override
public List<DictDataVo> selectDictDataByTypeTree(String dictType) {

    //DictDataVo dictDataVo = DictDataVo.builder().dictType("fz_yj_jcbz").build();
    DictDataVo dictDataVo = new DictDataVo();
    dictDataVo.setDictType("fz_yj_jcbz");
    List<DictDataVo> dictDataVoList = dictDataMapper.selectDictTypeTreeList(dictDataVo);
    //父节点
    List<DictDataVo> collect = dictDataVoList.stream().filter(e -> e.getIdP()==0).map(
            (e) -> {
                e.setChildList(getChildrens(e, dictDataVoList));
                return e;
            }
    ).collect(Collectors.toList());

    return collect;
}


/***
 * 子节点
 * @param root
 * @param all
 * @return
 */
public List<DictDataVo> getChildrens(DictDataVo root, List<DictDataVo> all) {
    List<DictDataVo> childen = all.stream().filter(e -> {
        return Objects.equals(e.getIdP(), root.getId());
    }).map(
            (e) -> {
                e.setChildList(getChildrens(e, all));
                return e;
            }
    ).collect(Collectors.toList());
    return childen;
}