Spring Boot中@Autowired无法注解

淩亂°似流年 2022-05-15 23:59 247阅读 0赞

今天在使用Spring Boot main方法启动项目时遇到`@Autowdired`注解无法注入错误。  
错误信息：

Parameter 0 of method setUserService in com.th.controller.SearchController required a bean of type 'com.th.service.UserService' that could not be found. Action:
    
    Consider defining a bean of type 'com.th.service.UserService' in your configuration.

**SearchController代码类：**

package com.th.controller;
    
    import java.util.List;
    import java.util.stream.Collectors;
    import javax.validation.Valid;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.http.ResponseEntity;
    import org.springframework.validation.Errors;
    import org.springframework.web.bind.annotation.RequestBody;
    import org.springframework.web.bind.annotation.RestController;
    import com.th.model.AjaxResponseBody;
    import com.th.model.SearchCriteria;
    import com.th.model.User;
    import com.th.service.UserService;
    
    @RestController
    public class SearchController {
    
        UserService userService;
    
        @Autowired
        public void setUserService(UserService userService) {
            this.userService = userService;
        }
    
        @PostMapping("/api/search")
        public ResponseEntity<?> getSearchResultViaAjax(@Valid @RequestBody SearchCriteria search, Errors errors) {
    
            AjaxResponseBody result = new AjaxResponseBody();
    
            if (errors.hasErrors()) {
    
                result.setMsg(
                        errors.getAllErrors().stream().map(x -> x.getDefaultMessage()).collect(Collectors.joining(",")));
                return ResponseEntity.badRequest().body(result);
            }
    
            List<User> users = userService.findByUserNameOrEmail(search.getUsername());
            if (users.isEmpty()) {
                result.setMsg("no user found!");
            } else {
                result.setMsg("success");
            }
    
            result.setResult(users);
    
            return ResponseEntity.ok(result);
        }
    }

**解决：**  
1、检查对应的service类，controller类有没有在类上注解`@Service`，`@RestController`  
2、检查main启动类是否在service层，dao层的上一级，否则程序扫描不到