一、表单验证
改造 Girl 对象，给 age 字段加校验最小值为18，并给出错误提示。
@Entity
public class Girl {
@Id
@GeneratedValue
private Integer id;
private String cupSize;
@M<span class="hljs-keyword">in</span>(value = 18, message = <span class="hljs-string">"未成年少女禁止入内"</span>)
private Integer age;
public <span class="hljs-function"><span class="hljs-title">Girl</span></span>() {
}
//getter、setter 方法省略
}相应的 Controller 方法，用 Girl 对象接收传递过来的参数，并加上 @Validated 注解。BindingResult 用来接收错误信息
@PostMapping(value = "/girl/add")
public Girl add(@Validated Girl girl, BindingResult bindingResult) {
if(bindingResult.hasErrors()){
System.out.println(bindingResult.getFieldError().getDefaultMessage());
return null;
}
return repository.save(girl);
}如果传递的 age 小于 18，则会报错。
注意：@NotNull 和 @NotEmpty 和@NotBlank 区别 @NotEmpty 用在集合类上面 @NotBlank 用在String上面 @NotNull 用在基本类型上
二、使用 AOP 处理请求
先在 pom.xml 文件中添加 AOP 依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>新建 HttpAspect.java
package com.solo.test01.aspect;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import javax.servlet.http.HttpServletRequest;
@Aspect
@Component
public class HttpAspect {
private static final Logger logger = LoggerFactory.getLogger(HttpAspect.class);
//指定切点
@Pointcut(<span class="hljs-string">"execution(public * com.solo.test01.controller.GirlController.*(..))"</span>)
public void <span class="hljs-function"><span class="hljs-title">log</span></span>() {
}
@Before(<span class="hljs-string">"log()"</span>)
public void <span class="hljs-keyword">do</span>Before(JoinPoint joinPoint) {
logger.info(<span class="hljs-string">"doBefore-----"</span>);
//获取 http 请求的内容
ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
HttpServletRequest request = attributes.getRequest();
//url
logger.info(<span class="hljs-string">"url: {}"</span>, request.getRequestURL());
//method
logger.info(<span class="hljs-string">"method: {}"</span>, request.getMethod());
// ip
logger.info(<span class="hljs-string">"ip: {}"</span>, request.getRemoteAddr());
//方法
logger.info(<span class="hljs-string">"class_method: {}"</span>, joinPoint.getSignature().getDeclaringTypeName() <span class="hljs-string">","</span> joinPoint.getSignature().getName());
//参数
logger.info(<span class="hljs-string">"params: {}"</span>, joinPoint.getArgs());
}
@After(<span class="hljs-string">"log()"</span>)
public void <span class="hljs-function"><span class="hljs-title">doAfter</span></span>() {
logger.info(<span class="hljs-string">"doAfter-----"</span>);
}
@AfterReturning(returning = <span class="hljs-string">"object"</span>, pointcut = <span class="hljs-string">"log()"</span>)
public void <span class="hljs-keyword">do</span>AfterReturning(Object object){
logger.info(<span class="hljs-string">"response: {}"</span>, object.toString());
}
}@Pointcut 指定切点，在 @Before 中获取 http 请求的内容，@AfterReturning 获取返回的内容。
三、指定统一返回格式
创建 Result 对象为统一返回数据格式
public class Result<T> {
private Integer code;
private String msg;
private T data;
// get, <span class="hljs-built_in">set</span>方法省略
}封装工具类 ResultUtils
/**
* 返回结果的工具类封装
*/
public class ResultUtils {
public static Result success(Object obj) {
Result result = new Result();
result.setCode(0);
result.setMsg("成功");
result.setData(obj);
return result;
}
public static Result success() {
return success(null);
}
public static Result error(Integer code, String msg) {
Result result = new Result();
result.setCode(code);
result.setMsg(msg);
return result;
}
}不同状态返回相同格式的结果
代码语言：javascript复制@PostMapping(value = "/girl/add")
public Result<Girl> add(@Validated Girl girl, BindingResult bindingResult) {
if (bindingResult.hasErrors()) {
return ResultUtils.error(1, bindingResult.getFieldError().getDefaultMessage());
}
return ResultUtils.success(repository.save(girl));
}四、全局捕获异常处理
假如在 Service 中抛出了异常
@Component
public class GirlService {
@Autowired
GirlRepository repository;
public void getAge(Integer id){
Girl girl = repository.findById(id).get();
Integer age = girl.getAge();
<span class="hljs-keyword">if</span>(age <= 10){
// 还在上小学吧
throw new GirlException(ResultEnum.PRIMARY_SCHOOL);
}<span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span>(age > 10 && age < 16){
// 还在上中学吧
throw new GirlException(ResultEnum.MIDDLE_SCHOOL);
}
}
}定义一个 ExceptionHandle 来全局捕获 GirlException 异常
@ControllerAdvice
public class ExceptionHandle {
@ExceptionHandler(value = GirlException.class)
@ResponseBody
public Result handle(Exception e){
if(e instanceof GirlException){
GirlException girlException = (GirlException) e;
return ResultUtils.error(girlException.getCode(), e.getMessage());
}
return ResultUtils.error(-1, "未知错误");
}
}这样当出现指定异常时就会被全局捕获到。
GirlException 是自定义异常，代码如下：
public class GirlException extends RuntimeException {
private Integer code;
public <span class="hljs-function"><span class="hljs-title">GirlException</span></span>() {
}
public GirlException(ResultEnum resultEnum) {
super(resultEnum.getMsg());
this.code = resultEnum.getCode();
}
public Integer <span class="hljs-function"><span class="hljs-title">getCode</span></span>() {
<span class="hljs-built_in">return</span> code;
}
public void <span class="hljs-built_in">set</span>Code(Integer code) {
this.code = code;
}
}要继承 RuntimeException ，不要继承 Exception ，否则事务不会回滚。
将所有错误码和错误信息都封装到枚举类里，便于统一管理。
代码语言：javascript复制public enum ResultEnum {
UNKNOWN(-1, "未知错误"),
SUCCESS(0, "成功"),
PRIMARY_SCHOOL(100, "还是小学生吧"),
MIDDLE_SCHOOL(101, "是中学生吧")
;
private Integer code;
private String msg;
ResultEnum(Integer code, String msg) {
this.code = code;
this.msg = msg;
}
public Integer <span class="hljs-function"><span class="hljs-title">getCode</span></span>() {
<span class="hljs-built_in">return</span> code;
}
public String <span class="hljs-function"><span class="hljs-title">getMsg</span></span>() {
<span class="hljs-built_in">return</span> msg;
}
}
