List转树json

node.java:

import java.util.List;




public class Node {
private static final long serialVersionUID = -2721191232926604726L;


    private int id;


    private int parentId;


    private Node parent;


    private List<Node> children;


    private String name;


    private int level;


    private int sort;


    private int rootId;


    private String type;


    private boolean isLeaf;


    private String description;


    public Node() {
        super();
    }


    public Node(int id, int parentId, String name) {
        super();
        this.id = id;
        this.parentId = parentId;
        this.name = name;
    }


    public String getDescription() {
        return description;
    }


    public void setDescription(String description) {
        this.description = description;
    }


    public int getId() {
        return id;
    }


    public void setId(int id) {
        this.id = id;
    }


    public Node getParent() {
        return parent;
    }


    public void setParent(Node parent) {
        this.parent = parent;
    }


    public int getParentId() {
        return parentId;
    }


    public void setParentId(int parentId) {
        this.parentId = parentId;
    }


    public String getName() {
        return name;
    }


    public void setName(String name) {
        this.name = name;
    }


    public int getLevel() {
        return level;
    }


    public void setLevel(int level) {
        this.level = level;
    }


    public String getType() {
        return type;
    }


    public List<Node> getChildren() {
        return children;
    }


    public void setChildren(List<Node> children) {
        this.children = children;
    }


    public void setType(String type) {
        this.type = type;
    }


    public boolean isLeaf() {
        return isLeaf;
    }


    public void setLeaf(boolean isLeaf) {
        this.isLeaf = isLeaf;
    }


    public int getSort() {
        return sort;
    }


    public void setSort(int sort) {
        this.sort = sort;
    }


    public int getRootId() {
        return rootId;
    }


    public void setRootId(int rootId) {
        this.rootId = rootId;
    }


    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + id;
        result = prime * result + parentId;
        return result;
    }


    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Node other = (Node) obj;
        if (id != other.id)
            return false;
        if (parentId != other.parentId)
            return false;
        return true;
    }


    @Override
    public String toString() {
        return "Node {id=" + id + ", parentId=" + parentId + ", children="
                + children + ", name=" + name + ", level =" + level + "}";
    }
}

Test.java:

public class Test {    private List<Node> buildListToTree(List<Node> dirs) {        List<Node> roots = findRoots(dirs);        List<Node> notRoots = (List<Node>) CollectionUtils                .subtract(dirs, roots);        for (Node root : roots) {            root.setChildren(findChildren(root, notRoots));        }        return roots;    }    public List<Node> findRoots(List<Node> allNodes) {        List<Node> results = new ArrayList<Node>();        for (Node node : allNodes) {            boolean isRoot = true;            for (Node comparedOne : allNodes) {                if (node.getParentId() == comparedOne.getId()) {                    isRoot = false;                    break;                }            }            if (isRoot) {                node.setLevel(0);                results.add(node);                node.setRootId(node.getId());            }        }        return results;    }    private List<Node> findChildren(Node root, List<Node> allNodes) {        List<Node> children = new ArrayList<Node>();        for (Node comparedOne : allNodes) {            if (comparedOne.getParentId() == root.getId()) {                comparedOne.setParent(root);                comparedOne.setLevel(root.getLevel() + 1);                children.add(comparedOne);            }        }        List<Node> notChildren = (List<Node>) CollectionUtils.subtract(allNodes, children);        for (Node child : children) {            List<Node> tmpChildren = findChildren(child, notChildren);            if (tmpChildren == null || tmpChildren.size() < 1) {                child.setLeaf(true);            } else {                child.setLeaf(false);            }            child.setChildren(tmpChildren);        }        return children;    }    public static void main(String[] args) {        Test tb = new Test();        List<Node> allNodes = new ArrayList<Node>();        allNodes.add(new Node(1, 0, "节点1"));        allNodes.add(new Node(2, 0, "节点2"));        allNodes.add(new Node(3, 0, "节点3"));        allNodes.add(new Node(11, 7, "节点11"));        allNodes.add(new Node(4, 1, "节点4"));        allNodes.add(new Node(5, 1, "节点5"));        allNodes.add(new Node(6, 1, "节点6"));        allNodes.add(new Node(7, 4, "节点7"));        allNodes.add(new Node(8, 4, "节点8"));        allNodes.add(new Node(9, 5, "节点9"));        allNodes.add(new Node(10, 100, "节点10"));        List<Node> roots = tb.buildListToTree(allNodes);        JSONArray array = new JSONArray();        for (Node node : roots) {           //System.out.println(node.getName());            JSONObject o = new JSONObject();            o.put("id", node.getId());            o.put("name", node.getName());            List<Node> child = node.getChildren();            if(child!=null && child.size() > 0){                tb.fillChildren(o, child);            }            array.add(o);        }        System.out.println(array);    }    private void fillChildren(JSONObject o, List<Node> childs) {        JSONArray array2 = new JSONArray();        for (Node node : childs) {            JSONObject oo = new JSONObject();            List<Node> child = node.getChildren();            oo.put("id", node.getId());            oo.put("name", node.getName());           // System.out.println(node.getName());            if(child!=null && child.size() > 0){                fillChildren(oo, child);            }            array2.add(oo);            o.put("child", array2);        }       // System.out.println(o);    }}