背景
页面查询的时候，我们一般是从库里直接拿数据，但是库里的数据有些字段是字典的，我们库里保存的也是一下代码值，这时候就需要我们对返回的代码值联合字典表进行翻译
涉及知识点：
- 注解类
- ResponseBodyAdvice类
- 反射
思路
做一个拦截器，拦截返回前端的数据，然后统一对返回数据里的代码值进行分类。但是我们只需要拦截那些需要进行翻译的请求，并不需要拦截全部的响应，这就需要我们声明一个标志，当拦截器捕捉到这个标志的时候，就拦截这个响应，对里面的数据进行翻译。我们使用注解类来作为标志。
代码
声明DictTypeSensible注解类
import java.lang.annotation.*;
/**
*
* 针对单个字典
* @Author: huangjun
* @Date: 2021/8/18 13:10
* @Version 1.0
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface DictTypeSensible {
/**
* 实体类字段
*/
String value();
/**
* 字典code,默认使用 value 转下划线形式
*/
String code() default "dm";
/**
* dmb表的类型（dmbyw）
*/
String type() default "";
}
声明DictTypeSensibles
import java.lang.annotation.*;
/**
* @Author: huangjun
* @Date: 2021/8/18 13:12
* @Version 1.0
*
* 多个字典值
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface DictTypeSensibles {
DictTypeSensible[] value();
}
定义拦截器DictTypeSensibleAspect
import cn.hutool.core.util.ReflectUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.mybatisplus.extension.api.R;
import com.ufgov.gdyb.expansion.config.constant.RedisKeyConstant;
import com.ufgov.test.abc.entity.main.Dmb;
import com.ufgov.test.entity.service.main.IDmbService;
import com.ufgov.test.entity.util.RedisService;
import lombok.AllArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
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.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
import java.lang.reflect.Field;
/**
* @Author: huangjun
* @Date: 2021/8/18 13:13
* @Version 1.0
*/
@Slf4j
@ControllerAdvice
@AllArgsConstructor
public class DictTypeSensibleAspect implements ResponseBodyAdvice<Object> {
@Autowired
private RedisService redisService;
@Autowired
private IDmbService dmbMainService;
@Override
public boolean supports(MethodParameter methodParameter, Class<? extends HttpMessageConverter<?>> aClass) {
return methodParameter.hasMethodAnnotation(DictTypeSensible.class)
|| methodParameter.hasMethodAnnotation(DictTypeSensibles.class);
}
@Override
public Object beforeBodyWrite(Object o, MethodParameter methodParameter, MediaType mediaType, Class<? extends HttpMessageConverter<?>> aClass, ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse) {
if (o == null) {
return null;
}
// 获取方法 注解参数
DictTypeSensible[] sensibles;
if (methodParameter.hasMethodAnnotation(DictTypeSensible.class)) {
DictTypeSensible sensible = methodParameter.getMethodAnnotation(DictTypeSensible.class);
sensibles = new DictTypeSensible[]{sensible};
} else {
DictTypeSensibles typeSensibles = methodParameter.getMethodAnnotation(DictTypeSensibles.class);
sensibles = typeSensibles == null ? new DictTypeSensible[]{} : typeSensibles.value();
}
// 处理返回值
this.dis(o, sensibles);
return o;
}
private void dis(Object obj, DictTypeSensible[] sensibles) {
// 处理返回类型
if (obj instanceof R) {
this.dis(((R) obj).getData(), sensibles);
return;
}
if (obj instanceof IPage) {
((IPage) obj).getRecords().forEach(e -> this.dis(e, sensibles));
return;
}
//TODO 可以自定义其他的返回值，其本质目的是为了获取返回的具体数据
Class<?> clazz = obj.getClass();
for (DictTypeSensible sensible : sensibles) {
try {
Field field = ReflectUtil.getField(clazz, sensible.value());
if (field == null || !field.getType().getSimpleName().contains("String")) {
log.warn("字典 {} 进行忽略,不存在或者是非String类型 ------", sensible.value());
continue;
}
Object val = ReflectUtil.getFieldValue(obj, field);
if (val == null) {
continue;
}
String type = StrUtil.isEmpty(sensible.type())
? StrUtil.toUnderlineCase(sensible.value()) : sensible.type();
String label = redisService.get(RedisKeyConstant.REDIS_DICT_NAME_SPACE + type + "_" + val);
if (StringUtils.isBlank(label)){
Dmb dmbMain = dmbMainService.getBaseMapper().selectOne(Wrappers.<Dmb>lambdaQuery().eq(Dmb::getDmbyw, type).eq(Dmb::getDm, val).eq(Dmb::getAgencyCode,"440199").groupBy(Dmb::getDmbyw));
label = dmbMain == null ? null : dmbMain.getDmfy();
if (StringUtils.isBlank(label)){
continue;
}
redisService.set(RedisKeyConstant.REDIS_DICT_NAME_SPACE + type + "_" + val,label);
}
ReflectUtil.setFieldValue(obj, field, label);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
使用方式，直接在Controller类上面使用，使用方式类似于@ApiImplicitParams注解
@Api(tags = "服务")
@RestController
@RequestMapping("/my")
public class TestController {
@Autowired
TestService testService;
@ApiResponses({})
@ApiImplicitParams({
// @ApiImplicitParam(value = "", name = "params", required = true, paramType = "body", dataType = "Map", dataTypeClass = Map.class)
})
@ApiOperation(value = "根据条件查询明细表内容", notes = "", httpMethod = "POST")
@PostMapping("/getPage")
@ResponseBody
@DictTypeSensibles({
@DictTypeSensible(value = "payType",type ="PAYTYPE"),
@DictTypeSensible(value = "personType",type = "PERSONTYPE"),
@DictTypeSensible(value = "chechType",type = "CHECKTYPE"),
})
public R getPage(@RequestBody Map params) {
R r= R.ok( testService.getListPageByMap(params));
r.setCode(200);
return r;
}
}
补充说明ResponseBodyAdvice
ResponseBodyAdvice类也是个拦截器，是针对响应体进行拦截，里面有两个方法supports和beforeBodyWrite，当supports方法返回true时，执行beforeBodyWrite方法，否则不执行beforeBodyWrite。ResponseBodyAdvice还有个@ControllerAdvice注解可以声明需要拦截的包或类，具体自行学习吧
