基于FeignClient提供简单的用户查询服务

前言：

　　由于系统升级，之前的员工数据库（mongo库）被弃用，改为用python维护的mysql库，其他系统访问通过http请求，表结构对外不可见，其他系统之前对员工mongo库的依赖要解除。每套系统都去写请求的接口太麻烦，所以打算写一个员工查询服务，http请求用原生的FeignClient实现。

实现思路：

　　场景：python端只提供了查询所有员工，其他系统请求多种多样。

　　解决：请求接口 -->  查询所有员工  -->  FeignClient包装的http请求  -->  过滤条件

实现步骤演示：

• Feign包装的http请求：

 /**
  * 对外暴露接口.
  */
 @FeignClient(name = XXXXClientConfig.APPLICATION_NAME, url = "https://xx.xxxx.com")
 public interface IEmployService {

     @RequestMapping(value = "/xx/employee/search",
             headers = {"Content-Type=application/json",
             "App-Id=xxx",
             "App-Secret=xxxx"})
     @ResponseBody
     ReturnUser getAllUser(@RequestBody GetAllUserForm getAllUserForm);

 }

• 员工服务接口：

 @FeignClient(XXXXConfig.APPLICATION_NAME)
 public interface IUserService {

     @RequestMapping(value = "/xxxx/getAll", method = RequestMethod.GET)
     List<User> getAll();

     @RequestMapping(value = "/xxxx/getUserByIds", method = RequestMethod.POST)
     List<User> getUserByIds(@RequestBody List<String> userIds);

     @RequestMapping(value = "/xxxx/getById", method = RequestMethod.GET)
     User getById(@RequestParam(value = "userId") String userId);

     @RequestMapping(value = "/xxxx/getByQuery", method = RequestMethod.POST)
     List<User> getByQuery(@RequestBody UserQuery userQuery);
 }

• 员工服务实现：

 @RestController
 public class UserSearchService implements IUserService {
     private final static Logger log = LoggerFactory.getLogger("xxx");
     private List<User> users = null;
     private Long lastTime = null;
     @Resource
     private IEmployService employService;

     @Override
     public List<User> getAll() {
         if(users != null && users.size() > 0 && lastTime != null && (System.currentTimeMillis() - lastTime) <= 1000*60*10){
             return users;
         }
         try {
             GetAllUserForm form = new GetAllUserForm();
             form.setPageNo(1);
             form.setPageSize(99999);
             ReturnUser allUser = employService.getAllUser(form);
             users = new ArrayList<>();
             allUser.getData().getRecords().forEach(returnUser -> {
                 User user = getUserFromReturnUser(returnUser);
                 users.add(user);
             });
             lastTime = System.currentTimeMillis();
             return users;
         }catch (Exception e){
             if(users.size() > 0){
                 return users;
             }else {
                 throw new RuntimeException("getAll(): user is null");
             }
         }
     }

     @Override
     public List<User> getUserByIds(@RequestBody List<String> userIds) {
         List<User> all = getAll();
         List<User> users = all.stream().filter(user -> userIds.contains(user.getId())).collect(Collectors.toList());
         return users;
     }

     @Override
     public User getById(@RequestParam(value = "userId") String userId) {
         List<User> all = getAll();
         List<User> users = all.stream().filter(user -> user.getId().equals(userId))
                 .collect(Collectors.toList());
         return users.size() == 1? users.get(0):null;
     }

     @Override
     public List<User> getByQuery(@RequestBody UserQuery userQuery) {
         List<User> list = new ArrayList<>();
         getAll().stream().filter(user -> {
             if (CommonUtil.isNotBlank(userQuery.getName())) {
                 if (!userQuery.getName().equals(user.getName()) &&
                         !userQuery.getName().equals(user.getRealName())) {
                     return false;
                 }
             }
             if (CommonUtil.isNotBlank(userQuery.getKeyword())) {
                 if (!user.getName().contains(userQuery.getKeyword()) &&
                         !user.getRealName().contains(userQuery.getKeyword())) {
                     return false;
                 }
             }
             if (userQuery.getIds() != null) {
                 if (!userQuery.getIds().contains(String.valueOf(user.getNumber()))) {
                     return false;
                 }
             }
             return true;
         }).forEach(user -> {
             list.add(user);
         });
         return list;
     }

     private User getUserFromReturnUser(Employee returnUser) {
         User user = new User();
         user.setName(returnUser.getName());
         return user;
     }

 }

• springboot启动添加

    @EnableFeignClients(basePackages = {XXXXClientConfig.PACKAGE_PATH})