com.github.dennisit.vplus.data.criteria.action.TreeAction Maven / Gradle / Ivy
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package com.github.dennisit.vplus.data.criteria.action;
import com.github.dennisit.vplus.data.criteria.TreeCriteria;
import com.google.common.collect.Lists;
import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.lang3.StringUtils;
import java.util.List;
/**
* 树形折叠行为
* @author Elon.su
*/
public final class TreeAction {
/**
* 属性折叠行为
*/
private TreeAction(){
}
/**
* 递归实现List折叠成Tree
* @param list 集合
* @param 泛型约束
* @return 折叠后的集合对象
*/
public static List tree(List list){
if (CollectionUtils.isEmpty(list)) {
return Lists.newArrayList();
}
List items = Lists.newArrayList();
// 抽取根节点
list.stream().filter((x) -> x.isTreeRoot())
.forEach((x) -> {
items.add(x);
});
// 递归组装成tree
for (T item : items) {
tree(list, item);
}
return items;
}
/**
* Tree形折叠
* @param list 集合
* @param t 集合元素
* @param 泛型约束
*/
private static void tree(List list, T t) {
final String pid = t.getTreeId();
final List data = Lists.newArrayList();
list.stream()
.filter((x) -> StringUtils.isNotBlank(x.getTreeParentId()) && pid.equals(x.getTreeParentId()))
.forEach((x) -> {
data.add(x);
// 递归添加
tree(list, x);
});
if (!data.isEmpty()) {
t.setSubList(data);
}
}
}