1、表结构数据
2、实体类定义
1 public class ParentHMClassify { 2 3 private Integer id; 4 5 private String classifyName; 6 7 private Integer parentId; 8 9 private Integer sort; 10 /** 11 * 子集合 12 */ 13 List<ParentHMClassify> childList; 14 }
3、查询方法
1 @Autowired 2 private HMClassifyMapperCustom classifyMapperCustom; 3 4 @Test 5 public void query() { 6 // 查询 db 7 List<ParentHMClassify> classifyList1 = classifyMapperCustom.getClassifyList1(); 8 // 存放根节点信息 9 List<ParentHMClassify> rootList = new ArrayList<>(); 10 for (ParentHMClassify parent : classifyList1) { 11 if (parent.getParentId() == 0) { 12 // 添加根节点 13 rootList.add(parent); 14 // 找到根节点下面的子节点菜单 15 findChilds(parent, classifyList1); 16 } 17 } 18 System.out.println("result:" + JSONObject.toJSONString(rootList)); 19 } 20 21 /** 22 * 递归查询子节点 23 * 24 * @param root 25 * @param list 26 */ 27 public void findChilds(ParentHMClassify root, List<ParentHMClassify> list) { 28 System.out.println("查找子节点..."); 29 List<ParentHMClassify> childList = new ArrayList<>(); 30 for (ParentHMClassify menu : list) { 31 if (root.getId() == menu.getParentId()) { 32 childList.add(menu); 33 } 34 } 35 // 子节点不存在，就不需要在遍历子节点中的节点了 直接返回 36 if (childList.size() == 0) return; 37 // 设置父节点的子节点列表 38 root.setChildList(childList); 39 // 若子节点存在，接着递归调用该方法，查询子节点的子节点 40 for (ParentHMClassify childs : childList) { 41 findChilds(childs, list); 42 } 43 }
4、子父级菜单数据结构为：
1 [ 2 { 3 "classifyName":"VIP相关模板", 4 "id":4, 5 "parentId":0, 6 "sort":1 7 }, 8 { 9 "childList":[ 10 { 11 "childList":[ 12 { 13 "classifyName":"材料遗失声明模板", 14 "id":9, 15 "parentId":6, 16 "sort":1 17 }, 18 { 19 "classifyName":"345345", 20 "id":36, 21 "parentId":6, 22 "sort":2 23 } 24 ], 25 "classifyName":"档案科", 26 "id":6, 27 "parentId":5, 28 "sort":1 29 }, 30 { 31 "childList":[ 32 { 33 "childList":[ 34 { 35 "classifyName":"公正委托书模板", 36 "id":13, 37 "parentId":10, 38 "sort":1 39 }, 40 { 41 "classifyName":"交房委托书", 42 "id":14, 43 "parentId":10, 44 "sort":2 45 }, 46 { 47 "classifyName":"未到场补充协议", 48 "id":15, 49 "parentId":10, 50 "sort":3 51 }, 52 { 53 "classifyName":"未到场授权委托书", 54 "id":16, 55 "parentId":10, 56 "sort":4 57 } 58 ], 59 "classifyName":"买卖材料模板", 60 "id":10, 61 "parentId":7, 62 "sort":1 63 }, 64 { 65 "classifyName":"租赁材料模板", 66 "id":11, 67 "parentId":7, 68 "sort":2 69 } 70 ], 71 "classifyName":"签约部", 72 "id":7, 73 "parentId":5, 74 "sort":2 75 }, 76 { 77 "childList":[ 78 { 79 "classifyName":"收入证明模板", 80 "id":12, 81 "parentId":8, 82 "sort":1 83 } 84 ], 85 "classifyName":"贷款部", 86 "id":8, 87 "parentId":5, 88 "sort":3 89 } 90 ], 91 "classifyName":"交易服务中心", 92 "id":5, 93 "parentId":0, 94 "sort":2 95 }, 96 { 97 "childList":[ 98 { 99 "childList":[ 100 { 101 "childList":[ 102 { 103 "classifyName":"四级菜单", 104 "id":41, 105 "parentId":40, 106 "sort":1 107 } 108 ], 109 "classifyName":"三级菜单", 110 "id":40, 111 "parentId":39, 112 "sort":2 113 } 114 ], 115 "classifyName":"二级菜单", 116 "id":39, 117 "parentId":38, 118 "sort":1 119 }, 120 { 121 "childList":[ 122 { 123 "childList":[ 124 { 125 "classifyName":"四级菜单-1", 126 "id":44, 127 "parentId":43, 128 "sort":1 129 } 130 ], 131 "classifyName":"三级菜单-1", 132 "id":43, 133 "parentId":42, 134 "sort":1 135 } 136 ], 137 "classifyName":"二级菜单-1", 138 "id":42, 139 "parentId":38, 140 "sort":2 141 } 142 ], 143 "classifyName":"一级菜单", 144 "id":38, 145 "parentId":0, 146 "sort":3 147 } 148 ]
5、总结
先查询所有菜单集合数据，然后遍历菜单集合获取根节点集合，然后调用查询子节点方法并在子节点方法中进行递归查询。如果当前节点没有子节点，直接return 不需要在进行递归查询。相反如果当前节点有子节点则一直进行递归查询。