Java List 生成 树Java List 生成 树

package com.victop.ibs;import java.util.ArrayList;import java.util.List;import org.apache.commons.collections.CollectionUtils;public class TreeBuilder {    @SuppressWarnings("unchecked")    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;    }    @SuppressWarnings("unchecked")    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) {        TreeBuilder tb = new TreeBuilder();        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(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);        for (Node n : roots) {            System.out.println(n);        }    }}

package com.victop.ibs;import java.util.List;public class Node implements java.io.Serializable {    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 + "}";    }}

package com.victop.ibs;import java.util.ArrayList;import java.util.List;import org.apache.commons.collections.CollectionUtils;public class TreeBuilder {    @SuppressWarnings("unchecked")    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;    }    @SuppressWarnings("unchecked")    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) {        TreeBuilder tb = new TreeBuilder();        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(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);        for (Node n : roots) {            System.out.println(n);        }    }}

package com.victop.ibs;import java.util.List;public class Node implements java.io.Serializable {    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 + "}";    }}