大神帮忙出出主意json嵌套

[li_harry]

例如
表a
id username ip
1 admin 178
2 lj 123


表b
nectid command
1 rmdir
1 cp

现在List<map<string,object>> list = jdbctemplate.queryforlist('select * from a');
接下来要怎么遍历list，并通过a.id作为查询条件从b表中查询对应的command(select * from b where b.nectid = a.id)，
关键还要以嵌套json格式返回。就是这种格式：
[{"id":"1","username ":admin","ip":"178","command":[{"nectid":"1","command":"rmdir"},{"nectid":"1","command":"cp"}]},
{"id":"2","username ":"lj","ip":"123"}]

[Buguanjia-Ssj]

public class UserDO {
    private Long id;
    private String userName;
    private String ip;
    //TODO get and set
}

public class UserDTO extends UserDO {
    private List<String> command;
    //TODO get and set
}

public class UserCommandDO {
    private Long nectId;
    private String command;
    //TODO get and set
}

你这里的id和nectid肯定是一致的，command里的可以去掉，最后用list<UserDTO>封装数据 你从a表查询返回的数据用list<UserDO>封装

List<Long> idList = new ArrayList<>();
//可存储重复主键的map
Multimap<Long,String> map = ArrayListMultimap.create();
//判断list非空
for (UserDO user : userList) {
    idList.add(user.getId());
}
//根据idLIst从b表查询出数据list<UserCommandDO>
//判断list非空
for (UserCommandDO command : commandList) {
    map.put(commnd.getNectId(),command.getCommand());
}
List<UserDTO> dtoList = new ArrayList<>();
for (UserDO user : userList) {
    UserDTO dto = new UserDTO();
    dto.setId(user.getId());
    dto.setUserName(user.getUserName());
    dto.setIp(user.getIp());
    List<String> list = (List<String>)map.get(user.getId());
    dto.setCommand(list);
    dtoList.add(dto);
}
return dtoList;

[li_harry]

引用 1 楼 shansongjia 的回复:

public class UserDO {
    private Long id;
    private String userName;
    private String ip;
    //TODO get and set
}

public class UserDTO extends UserDO {
    private List<String> command;
    //TODO get and set
}

public class UserCommandDO {
    private Long nectId;
    private String command;
    //TODO get and set
}

你这里的id和nectid肯定是一致的，command里的可以去掉，最后用list<UserDTO>封装数据 你从a表查询返回的数据用list<UserDO>封装

List<Long> idList = new ArrayList<>();
//可存储重复主键的map
Multimap<Long,String> map = ArrayListMultimap.create();
//判断list非空
for (UserDO user : userList) {
    idList.add(user.getId());
}
//根据idLIst从b表查询出数据list<UserCommandDO>
//判断list非空
for (UserCommandDO command : commandList) {
    map.put(commnd.getNectId(),command.getCommand());
}
List<UserDTO> dtoList = new ArrayList<>();
for (UserDO user : userList) {
    UserDTO dto = new UserDTO();
    dto.setId(user.getId());
    dto.setUserName(user.getUserName());
    dto.setIp(user.getIp());
    List<String> list = (List<String>)map.get(user.getId());
    dto.setCommand(list);
    dtoList.add(dto);
}
return dtoList;

多谢回帖，不过现在项目用的是jdbc，没有用到hibernate，如果把一个类实例化作为另一类的属性定义，需不需要到xml文件做字段的定义？另外项目中表a和表b其实是两个有多表查询组成的视图，是否也可以用来映射两个类？

[Buguanjia-Ssj]

你用jdbc的话可以不用定义a,b对应的两个类

resultset set1 =  查询b表;
resultset set2 = 查询a表;
while(set1.next()) {
    map.put(set1.getLong("nectId"),set1.getString("command"));
}
while(set2.next()) {
   UserDTO dto = new UserDTO;
    Long id = set2.getLong("id");
    dto.setId(id);
    dto.setUserName(set2.getString("username"));
    dto.setIp(set2.getString("ip"));
    dto.setCommand((List<String>)map.get(id));
    dtoList.add(dto);
}