SpringBoot @RestControllerAdvice
目录
一. 需求场景
如下图所示，后台向前台响应数据的时候，所有的数据都需要放入自定义的封装Entity才返回给前台。现在想要每个Controller中的方法将原数据直接返回，然后通过某种方法 统一封装 处理。
image.png
二. 前期准备
⏹获取状态码的接口
<pre class="prettyprint hljs java" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; word-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">public interface IStatusCode {
int getCode();
String getMsg();
}</pre>
⏹响应状态码的枚举类
<pre class="prettyprint hljs groovy" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; word-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">import lombok.AllArgsConstructor;
import lombok.Getter;
@Getter
@AllArgsConstructor
public enum ResultCodeEnum implements IStatusCode {
SUCCESS(1000, "请求成功"),
FAILED(1001, "请求失败"),
VALIDATE_ERROR(1002, "参数校验失败"),
RESPONSE_PACK_ERROR(1003, "response返回包装失败");
private int code;
private String msg;
}</pre>
⏹业务状态码的枚举类
<pre class="prettyprint hljs groovy" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; word-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">import lombok.AllArgsConstructor;
import lombok.Getter;
@Getter
@AllArgsConstructor
public enum BusinessCodeEnum implements IStatusCode {
APP_ERROR(2000, "业务异常"),
PRICE_ERROR(2001, "价格异常");
private int code;
private String msg;
}</pre>
⏹自定义业务异常类
<pre class="prettyprint hljs scala" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; word-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">import lombok.Getter;
@Getter
public class BusinessException extends RuntimeException {
private int code;
private String msg;
// 手动设置异常
public BusinessException(IStatusCode codeEnum, String message) {
// message用于用户设置抛出错误详情
super(message);
// 状态码
this.code = codeEnum.getCode();
// 状态码配套的msg
this.msg = codeEnum.getMsg();
}
// 默认异常使用APP_ERROR状态码
public BusinessException(String message) {
super(message);
this.code = BusinessCodeEnum.APP_ERROR.getCode();
this.msg = BusinessCodeEnum.APP_ERROR.getMsg();
}
}</pre>
⏹自定义注解,标记该注解的方法不进行响应增强
让我们的方法更加 灵活 ，可以选择增强封装或者不增强。
<pre class="prettyprint hljs css" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; word-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target({ ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface NotControllerResponseAdvice {
}</pre>
三. 使用@RestControllerAdvice对响应进行增强
<pre class="prettyprint hljs swift" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; word-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
import java.util.Arrays;
import java.util.List;
// 对指定包下面的Controller进行增强
@RestControllerAdvice(basePackages = { "com.example.jmw.controller"})
public class ControllerResponseAdvice implements ResponseBodyAdvice<Object> {
@Override
public boolean supports(MethodParameter methodParameter, Class<? extends HttpMessageConverter<?>> converterType) {
List<Boolean> judgeResultList = Arrays.asList(
// :o:判断相应的类型是否为ResultVo类型
methodParameter.getParameterType().isAssignableFrom(ResultVo.class),
// :o:判断响应的方法上是否包含 NotControllerResponseAdvice 注解
methodParameter.hasMethodAnnotation(NotControllerResponseAdvice.class)
);
// 若包含其中一项,则不进行封装
return !judgeResultList.contains(true);
}
@Override
public Object beforeBodyWrite(Object body
, MethodParameter returnType
, MediaType selectedContentType
, Class<? extends HttpMessageConverter<?>> selectedConverterType
, ServerHttpRequest request
, ServerHttpResponse response
) {
// String类型不能直接包装
if (returnType.getGenericParameterType().equals(String.class)) {
ObjectMapper objectMapper = new ObjectMapper();
try {
// 将数据包装在ResultVo里后转换为json串进行返回
return objectMapper.writeValueAsString(ResultVo.build(body));
} catch (JsonProcessingException e) {
// 抛出自定义的业务异常
throw new BusinessException(ResultCodeEnum.RESPONSE_PACK_ERROR, e.getMessage());
}
}
// 否则直接包装成ResultVo返回
return ResultVo.build(body);
}
}</pre>
四. 效果
4.1 直接返回List
<pre class="prettyprint hljs less" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; word-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">@Controller
@RequestMapping("/test12")
public class Test12Controller {
@PostMapping("/test")
@ResponseBody
public List<String> test() {
return Arrays.asList("1", "2", "3");
}
}</pre>
⏹List被包装之后返回给前台
image.png
4.2 标记NotControllerResponseAdvice注解后返回List
⏹ List 未被包装，直接返回数据给前台
image.png
4.3 直接返回字符串
image.png
4.4 直接返回ResultVo类型数据
⏹返回的就是ResultVo类型，无需包装，直接返回数据给前台
image.png
