ElementUI组件Cascader级联选择器数据后台处理
Cascader级联选择器数据数据格式不知道的可以去官网看下；这里我就不表示什么了。
部门实体类：
1 import lombok.Data; 2 3 @Data 4 public class Department { 5 private Integer id; 6 7 private Integer parentId; 8 9 private String name; 10 11 public Department(Integer id, Integer parentId, String name) { 12 this.id = id; 13 this.parentId = parentId; 14 this.name = name; 15 } 16 17 public static TreeItem deptNode(Department dept) { 18 TreeItem treeItem = new TreeItem(); 19 treeItem.setId(dept.getId()); 20 treeItem.setName(dept.getName()); 21 treeItem.setParentId(dept.getParentId()); 22 return treeItem; 23 } 24 }
用户实体类：
1 import lombok.Data; 2 3 @Data 4 public class Employee { 5 6 private Integer id; 7 8 private String name; 9 10 private Integer deptId; 11 12 13 public Employee(Integer id, String name, Integer deptId) { 14 this.id = id; 15 this.name = name; 16 this.deptId = deptId; 17 } 18 19 public static TreeItem empNode(Employee emp) { 20 TreeItem treeItem = new TreeItem(); 21 treeItem.setId(emp.getId()); 22 treeItem.setName(emp.getName()); 23 treeItem.setParentId(emp.getDeptId()); 24 return treeItem; 25 } 26 }
返回数据实体类：
1 import lombok.Data; 2 3 import java.util.List; 4 5 @Data 6 public class TreeItem { 7 private Integer id; 8 9 private Integer parentId; 10 11 private String name; 12 13 private List<TreeItem> children; 14 }
数据处理操作，这里是用java8新的特性写的。不懂的可以学习下，挺好用的
1 import java.util.ArrayList; 2 import java.util.Arrays; 3 import java.util.List; 4 import java.util.Map; 5 import java.util.stream.Collectors; 6 7 public class App { 8 public static void main(String[] args) { 9 //创建部门 10 List<Department> deptList = Arrays.asList( 11 new Department(1, 0, "星宇"), 12 new Department(2, 1, "金3"), 13 new Department(3, 2, "金3/1"), 14 new Department(4, 2, "金3/2"), 15 new Department(5, 1, "总1"), 16 new Department(6, 5, "总1/2") 17 18 ); 19 //创建员工 20 List<Employee> empList = Arrays.asList( 21 new Employee(1, "张三", 5), 22 new Employee(2, "李四", 6), 23 new Employee(3, "王五", 2), 24 new Employee(4, "赵六", 2), 25 new Employee(5, "田七", 3), 26 new Employee(6, "牛八", 4) 27 ); 28 //转换成结点 29 List<TreeItem> allDept = deptList.stream() 30 .map(Department::deptNode) 31 .collect(Collectors.toList()); 32 //按照上级部门分组 33 Map<Integer, List<TreeItem>> deptMap = allDept.stream() 34 .collect(Collectors.groupingBy(TreeItem::getParentId)); 35 //给每个部门绑定子部门 36 allDept.forEach(node -> 37 node.setChildren(deptMap.get(node.getId())) 38 ); 39 40 List<TreeItem> treeItem = deptMap.get(0); 41 42 Map<Integer, List<TreeItem>> empMap = empList.stream() 43 .filter(emp -> emp.getDeptId() != null) 44 .map(Employee::empNode) 45 .collect(Collectors.groupingBy(TreeItem::getParentId)); 46 //BFS辅助队列 47 List<TreeItem> queue = new ArrayList<>(); 48 queue.addAll(treeItem); 49 for (int i = 0; i < queue.size(); i++) { 50 TreeItem node = queue.get(i); 51 //遍历时先将子部门放入队列中 52 if (node.getChildren() != null) { 53 queue.addAll(node.getChildren()); 54 } else { 55 node.setChildren(new ArrayList<>()); 56 } 57 //再将部门成员放入子结点中 58 List<TreeItem> children = empMap.get(node.getId()); 59 if (children != null) { 60 node.getChildren().addAll(children); 61 } 62 } 63 64 treeItem.forEach(x -> System.out.println(x)); 65 66 } 67 }
TreeItem(id=1, parentId=0, name=星宇, children=[TreeItem(id=2, parentId=1, name=金3, children=[TreeItem(id=3, parentId=2, name=金3/1, children=[TreeItem(id=5, parentId=3, name=田七, children=null)]), TreeItem(id=4, parentId=2, name=金3/2, children=[TreeItem(id=6, parentId=4, name=牛八, children=null)]), TreeItem(id=3, parentId=2, name=王五, children=null), TreeItem(id=4, parentId=2, name=赵六, children=null)]), TreeItem(id=5, parentId=1, name=总1, children=[TreeItem(id=6, parentId=5, name=总1/2, children=[TreeItem(id=2, parentId=6, name=李四, children=null)]), TreeItem(id=1, parentId=5, name=张三, children=null)])])
上面是我打印出来的数据，其实你们只要返回treeItem这个集合就可以了，这个数据结构符合Cascader级联选择器。
