public interface UserService {/*** 判斷用戶名是否存在*/public boolean queryUsernameIsExist(String username);} @Service public class UserServiceImpl implements UserService {@Autowiredpublic UsersMapper usersMapper;@Transactional(propagation = Propagation.SUPPORTS)@Overridepublic boolean queryUsernameIsExist(String username) {Example userExample = new Example(Users.class);Example.Criteria userCriteria = userExample.createCriteria();userCriteria.andEqualTo("username", username);Users result = usersMapper.selectOneByExample(userExample);return result == null ? false : true;}} <!-- apache 工具類 --> <dependency><groupId>commons-codec</groupId><artifactId>commons-codec</artifactId><version>1.11</version> </dependency> <dependency><groupId>org.apache.commons</groupId><artifactId>commons-lang3</artifactId><version>3.4</version> </dependency> <dependency><groupId>org.apache.commons</groupId><artifactId>commons-io</artifactId><version>1.3.2</version> </dependency> @Api(value = "注冊登錄", tags = {"用于注冊登錄的相關接口"}) @RestController @RequestMapping("passport") public class PassportController {@Autowiredprivate UserService userService;@ApiOperation(value = "用戶名是否存在", notes = "用戶名是否存在", httpMethod = "GET")@GetMapping("/usernameIsExist")public JSONResult usernameIsExist(@RequestParam String username) {// 1. 判斷用戶名不能為空if (StringUtils.isBlank(username)) {return JSONResult.errorMsg("用戶名不能為空");}// 2. 查找注冊的用戶名是否存在boolean isExist = userService.queryUsernameIsExist(username);if (isExist) {return JSONResult.errorMsg("用戶名已經存在");}// 3. 請求成功，用戶名沒有重復return JSONResult.ok();}}

?

超強干貨來襲 云風專訪：近40年碼齡，通宵達旦的技術人生

總結

以上是生活随笔為你收集整理的用户注册 - 判断用户名存在的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。