我在List中得到了一些数据,如下所示:
groupCode | groupMember
-------------------------------
001 | name1
-------------------------------
001 | name2
-------------------------------
002 | name3
-------------------------------
003 | name4
在一些I组可以有更多的组成员。所以我需要遍历列表并以这种方式对数据进行排序:
001 (List)
- name1 (List inside List)
- name2
002 (List)
- name3
- name4
我使用类Group和GroupMember。我该怎么办?
public class Group {
private String groupCode;
private GroupMember groupMember;
...我不能使用private List<GroupMember> groupMember;
这里
public class GroupMember {
private String name;
public String getName() {
return name;
}
答案 0 :(得分:1)
如果nvidia-settings
是原始的待处理列表,其内容为:
members
可通过以下代码实现:
Group [001, GroupMember [name1]]
Group [001, GroupMember [name2]]
Group [002, GroupMember [name3]]
Group [003, GroupMember [name4]]
然后,可以通过Java stream API的帮助完成所需的分组:
class GroupMember {
private String name;
public GroupMember(String name) {
super();
this.name = name;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return String.format("GroupMember [%s]", getName());
}
}
class Group {
private String groupCode;
private GroupMember groupMember;
public Group(String groupCode, GroupMember groupMember) {
super();
this.groupCode = groupCode;
this.groupMember = groupMember;
}
public String getGroupCode() {
return groupCode;
}
public void setGroupCode(String groupCode) {
this.groupCode = groupCode;
}
public GroupMember getGroupMember() {
return groupMember;
}
public void setGroupMember(GroupMember groupMember) {
this.groupMember = groupMember;
}
@Override
public String toString() {
return String.format("Group [%s, %s]", getGroupCode(), getGroupMember());
}
}
...
List<Group> members = new ArrayList<>();
members.add(new Group("001", new GroupMember("name1")));
members.add(new Group("001", new GroupMember("name2")));
members.add(new Group("002", new GroupMember("name3")));
members.add(new Group("003", new GroupMember("name4")));
在这种情况下,分组的内容将是:
import static java.util.stream.Collectors.*;
...
Map<String, List<GroupMember>> grouped = members
.stream()
.collect(groupingBy(Group::getGroupCode,
mapping(Group::getGroupMember, toList())));
根据需要。