Java通用樹構建方法

今天寫了一個通用樹構建方法，非常通用和簡單，分享出來

基礎類
@Data
public class Tree<T> {
    String id;
    String pId;
    List<T> children;
}
測試類
@Data
public class TreeDemo extends Tree<TreeDemo> {
    String name;
}
工具類
public class TreeUtils {
    public static List buildTree(List<Tree> trees, String pId) {
        for (Tree tree : trees) {
            for (Tree tree1 : trees) {
                if (tree1.getPId().equals(tree.getId())) {
                    if (tree.getChildren() == null) {
                        tree.setChildren(new ArrayList());
                    }
                    tree.getChildren().add(tree1);
                }
            }
        }
        return trees.stream().filter(tree -> tree.getPId().equals(pId)).collect(Collectors.toList());
    }
}
測試方法

public static void main(String[] args) {

    List<TreeDemo> treeDemo = TreeUtils.buildTree(Arrays.asList(new TreeDemo(){{
        setId("1");
        setName("name");
        setPId("-1");
    }},new TreeDemo(){{
        setId("2");
        setName("name-1");
        setPId("1");
    }},new TreeDemo(){{
        setId("3");
        setName("name-2");
        setPId("1");
    }}),"-1");
    System.out.println(treeDemo);
}