添加一些工具类

spring-boot-demo-util/src/main/java/com/xkcoding/util/TreeUtil.java

@@ -0,0 +1,129 @@
+package com.xkcoding.util;
+
+import com.google.common.collect.Lists;
+import com.xiaoleilu.hutool.json.JSONUtil;
+import com.xkcoding.util.domain.TreeNode;
+
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * <p>
+ * 把一个list集合,里面的bean含有 parentId 转为树形式
+ * </p>
+ *
+ * @package: com.xkcoding.util
+ * @description： 把一个list集合, 里面的bean含有 parentId 转为树形式
+ * @author: yangkai.shen
+ * @date: Created in 2017/12/7 上午10:26
+ * @copyright: Copyright (c) 2017
+ * @version: 0.0.1
+ * @modified: yangkai.shen
+ */
+public class TreeUtil {
+
+	/**
+	 * 测试层级
+	 *
+	 * @param args
+	 */
+	public static void main(String[] args) {
+		long start = System.currentTimeMillis();
+
+		List<TreeNode> treeObjectList = Lists.newArrayList();
+
+		treeObjectList.add(new TreeNode(1, "总部", 0, "0", 1, "总部", Lists.<TreeNode>newArrayList()));
+		treeObjectList.add(new TreeNode(2, "技术部", 1, "0,1", 1, "技术部", Lists.<TreeNode>newArrayList()));
+		treeObjectList.add(new TreeNode(3, "软件部", 2, "0,1,2", 1, "软件部", Lists.<TreeNode>newArrayList()));
+		treeObjectList.add(new TreeNode(4, "硬件部", 2, "0,1,2", 2, "硬件部", Lists.<TreeNode>newArrayList()));
+		treeObjectList.add(new TreeNode(5, "维修部", 4, "0,1,2,4", 1, "维修部", Lists.<TreeNode>newArrayList()));
+		treeObjectList.add(new TreeNode(6, "采购部", 4, "0,1,2,4", 2, "采购部", Lists.<TreeNode>newArrayList()));
+
+		TreeUtil mt = new TreeUtil();
+
+		List<TreeNode> ns = mt.getChildTreeNodes(treeObjectList, 0);
+
+		for (TreeNode m : ns) {
+			System.out.println(m);
+			System.out.println(JSONUtil.parseObj(m, false).toStringPretty());
+		}
+
+		long end = System.currentTimeMillis();
+
+		System.out.println("用时:" + (end - start) + "ms");
+	}
+
+	/**
+	 * 根据父节点 id 获取所有子节点
+	 *
+	 * @param list     列表
+	 * @param parentId 父节点 id
+	 * @return 所有子节点
+	 */
+	public List<TreeNode> getChildTreeNodes(List<TreeNode> list, Integer parentId) {
+		List<TreeNode> returnList = Lists.newArrayList();
+		for (Iterator<TreeNode> iterator = list.iterator(); iterator.hasNext(); ) {
+			TreeNode t = iterator.next();
+			// 一、根据传入的某个父节点ID,遍历该父节点的所有子节点
+			if (t.getParentId().equals(parentId)) {
+				recursionFn(list, t);
+				returnList.add(t);
+			}
+		}
+		return returnList;
+	}
+
+	/**
+	 * 递归列表
+	 *
+	 * @param list 列表
+	 * @param t    树节点
+	 */
+	private void recursionFn(List<TreeNode> list, TreeNode t) {
+		// 得到子节点列表
+		List<TreeNode> childList = getChildList(list, t);
+
+		t.setChildren(childList);
+		for (TreeNode tChild : childList) {
+			// 判断是否有子节点
+			if (hasChild(list, tChild)) {
+				Iterator<TreeNode> it = childList.iterator();
+				while (it.hasNext()) {
+					TreeNode n = it.next();
+					recursionFn(list, n);
+				}
+			}
+		}
+	}
+
+	/**
+	 * 判断是否存在子节点
+	 *
+	 * @param list
+	 * @param tChild
+	 * @return
+	 */
+	private boolean hasChild(List<TreeNode> list, TreeNode tChild) {
+		return getChildList(list, tChild).size() > 0;
+	}
+
+	/**
+	 * 获得子节点列表
+	 *
+	 * @param list
+	 * @param t
+	 * @return
+	 */
+	private List<TreeNode> getChildList(List<TreeNode> list, TreeNode t) {
+		List<TreeNode> tlist = Lists.newArrayList();
+		Iterator<TreeNode> it = list.iterator();
+		while (it.hasNext()) {
+			TreeNode n = it.next();
+			if (n.getParentId().equals(t.getId())) {
+				tlist.add(n);
+			}
+		}
+		return tlist;
+	}
+
+}

spring-boot-demo-util/src/main/java/com/xkcoding/util/domain/TreeNode.java

@@ -0,0 +1,55 @@
+package com.xkcoding.util.domain;
+
+import com.google.common.collect.Lists;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.List;
+
+/**
+ * <p>
+ * 树节点
+ * </p>
+ *
+ * @package: com.xkcoding.util.domain
+ * @description： 树节点
+ * @author: yangkai.shen
+ * @date: Created in 2017/12/7 上午10:27
+ * @copyright: Copyright (c) 2017
+ * @version: 0.0.1
+ * @modified: yangkai.shen
+ */
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class TreeNode {
+	/**
+	 * id 编号
+	 */
+	private Integer id;
+	/**
+	 * 节点名称
+	 */
+	private String name;
+	/**
+	 * 父节点 id
+	 */
+	private Integer parentId;
+	/**
+	 * 层级
+	 */
+	private String level;
+	/**
+	 * 当前层级顺序
+	 */
+	private Integer seq;
+	/**
+	 * 备注
+	 */
+	private String remark;
+	/**
+	 * 子节点列表
+	 */
+	private List<TreeNode> children = Lists.newArrayList();
+}