在controller层中的参数验证、通过全局异常处理进行处理。

1.全局异常处理

//全局异常
@ControllerAdvice
public class GlobalExceptionHandler {

    private static final Logger log = LoggerFactory.getLogger(GlobalExceptionHandler.class);

    @ExceptionHandler(MethodArgumentNotValidException.class)
    @ResponseBody
    public String handleMethodArgumentNotValid(HttpServletResponse response, Exception e) {
        response.setContentType("application/json;charset=UTF-8");
        response.setCharacterEncoding("UTF-8");

        ObjectMapper objectMapper = new ObjectMapper();

        //从异常中获得错误字段和信息
        MethodArgumentNotValidException ex = (MethodArgumentNotValidException) e;
        BindingResult bindingResult = ex.getBindingResult();
        Map map = new HashMap<>();
        for (FieldError error : bindingResult.getFieldErrors()) {
            String field = error.getField();
            String msg = error.getDefaultMessage();
            map.put(field, msg);
        }

        try {
             //参数出错返回code
            response.getWriter().print(objectMapper.writeValueAsString(
                    ResultUtil.of(GlobalErrorCodeConstants.BAD_REQUEST.getCode()

                            , GlobalErrorCodeConstants.BAD_REQUEST.getMessage(), map)));
        } catch (IOException exc) {
            log.error("统一参数异常处理响应失败", exc);
        }
        return null;
    }
}

2.Controller层中

import com.github.pagehelper.PageInfo;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;

import javax.validation.constraints.NotNull;

/**
 * @author cyb
 * @date 2020/10/14
 * @since 0.0.1
 */
@RestController
@RequestMapping("/demo")
public class DemoController {

    @Autowired
    private DemoService demoService;

    @GetMapping("")
    public Foo getFoo(Long fooId){
        return demoService.getFoo(fooId);
    }

    //这里的Select.class只是个标记看第三段代码
    @GetMapping("/listDemo")
    public Result> getFooPage(@Validated(Select.class) FooPO fooPO,
                                                @RequestParam("pageNum") Integer pageNum,
                                                @RequestParam("pageSize") Integer pageSize){
        return demoService.getFooPage(fooPO,pageNum,pageSize);
    }


}

3.FooPO参数对象类

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import org.hibernate.validator.constraints.Length;
import org.hibernate.validator.constraints.Range;

import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;

/**
 * @author cyb
 * @date 2020/10/12
 * @since 0.0.1
 */
//这个@Data注解是为了表示这是个完整的数据对象
@Data
public class FooPO {

    //这里的groups就是进行了分组，比如，比如第二段代码中只有select那么@NotNull并不会生效
    @Range(groups = { Select.class, Update.class,Delete.class},min = 0,message = "id参数错误")
    @NotNull(groups = {Update.class, Delete.class}, message = "id不能为null")
    private Long id;
}

4.存在的问题

无法在controller层对单个参数进行验证。比如

public class DemoController {

    @Autowired
    private DemoService demoService;

    //这里的NotNull就不回生效。还在查询为什么。有没有好心人跟我说下相关文档在哪。
    @GetMapping("")
    public Foo getFoo(@Validated @NotNull Long fooId){
        return demoService.getFoo(fooId);
    }