xxx|yyy|zzz|...

{
    "xxx": xxx,
    "yyy": yyy,
    "zzz": zzz,
    ...
}

public class PackHttpMessageConverter implements HttpMessageConverter<Object> {
    
  // 設(shè)置自定義的Content-Type類型，這樣就限定了只有請(qǐng)求的內(nèi)容類型是該類型才會(huì)使用該轉(zhuǎn)換器進(jìn)行處理
  private static final MediaType PACK = new MediaType("application", "pack", StandardCharsets.UTF_8) ;


  // 判斷當(dāng)前轉(zhuǎn)換器是否能夠讀取數(shù)據(jù)
  @Override
  public boolean canRead(Class<?> clazz, MediaType mediaType) {
    return PACK.equals(mediaType) ;
  }
  // 判斷當(dāng)前轉(zhuǎn)換器是否可以將結(jié)果數(shù)據(jù)進(jìn)行輸出到客戶端
  @Override
  public boolean canWrite(Class<?> clazz, MediaType mediaType) {
    return true ;
  }
  // 返回當(dāng)前轉(zhuǎn)換器只支持application/pack類型的數(shù)據(jù)格式
  @Override
  public List<MediaType> getSupportedMediaTypes() {
    return Arrays.asList(PACK) ;
  }


  // 從請(qǐng)求中讀取數(shù)據(jù)
  @Override
  public Object read(Class<? extends Object> clazz, HttpInputMessage inputMessage)
      throws IOException, HttpMessageNotReadableException {
    InputStream is = inputMessage.getBody() ;
    String res = IOUtils.toString(is, StandardCharsets.UTF_8) ;
    // 這里簡(jiǎn)單處理只針對(duì)Users類型的對(duì)象處理
    if (clazz == Users.class) {
      try {
        // 創(chuàng)建實(shí)例
        Users target = (Users) clazz.newInstance() ;
        String[] s = res.split("\\|");
        target.setId(Long.valueOf(s[0])) ;
        target.setName(s[1]) ;
        target.setAge(Integer.valueOf(s[2])) ;
        target.setIdNo(s[3]) ;
        return target ;
      } catch (InstantiationException | IllegalAccessException e) {
        e.printStackTrace() ;
      }
    }
    return null ;
  }


  // 將Controller方法返回值寫到客戶端
  @Override
  public void write(Object t, MediaType contentType, HttpOutputMessage outputMessage)
      throws IOException, HttpMessageNotWritableException {
    // 設(shè)置響應(yīng)頭為json格式
    outputMessage.getHeaders().add("Content-Type", "application/json;charset=UTF-8") ;
    ObjectMapper mapper = new ObjectMapper() ;
    OutputStream os = outputMessage.getBody();
    // 輸出結(jié)果內(nèi)容
    os.write(mapper.writeValueAsString(t).getBytes(StandardCharsets.UTF_8)) ;
    os.flush(); 
  }
  
}

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
  
  @Override
  public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
    converters.add(new PackHttpMessageConverter()) ;
  }
}

// 方法非常簡(jiǎn)單還是用的那些常用的類，@RequestBody接收請(qǐng)求body中的內(nèi)容
@PostMapping("/i")
public Object i(@RequestBody Users user) {
  System.out.println(handlerAdapter) ;
  return user ;
}

public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
  converters.add(0, new PackHttpMessageConverter()) ;
}

public class RequestResponseBodyMethodProcessor extends AbstractMessageConverterMethodProcessor {
  protected <T> Object readWithMessageConverters(NativeWebRequest webRequest, MethodParameter parameter,
      Type paramType) throws IOException, HttpMediaTypeNotSupportedException, HttpMessageNotReadableException {
    // ...
    // 讀取請(qǐng)求數(shù)據(jù)；調(diào)用父類方法
    Object arg = readWithMessageConverters(inputMessage, parameter, paramType);
    // ...
  }
}

public abstract class AbstractMessageConverterMethodArgumentResolver {
  protected <T> Object readWithMessageConverters(...) {
    // ...
    // 遍歷所有的消息轉(zhuǎn)換器
    for (HttpMessageConverter<?> converter : this.messageConverters) {
        Class<HttpMessageConverter<?>> converterType = (Class<HttpMessageConverter<?>>) converter.getClass();
        GenericHttpMessageConverter<?> genericConverter = (converter instanceof GenericHttpMessageConverter ? (GenericHttpMessageConverter<?>) converter : null);
        // 判斷當(dāng)前轉(zhuǎn)換器是否讀，也就上面我們自定義中實(shí)現(xiàn)的canRead方法
        if (genericConverter != null ? genericConverter.canRead(targetType, contextClass, contentType) :
            (targetClass != null && converter.canRead(targetClass, contentType))) {
          if (message.hasBody()) {
            HttpInputMessage msgToUse = getAdvice().beforeBodyRead(message, parameter, targetType, converterType);
            // 讀取具體的數(shù)據(jù)內(nèi)容
            body = (genericConverter != null ? genericConverter.read(targetType, contextClass, msgToUse) : ((HttpMessageConverter<T>) converter).read(targetClass, msgToUse));
            body = getAdvice().afterBodyRead(body, msgToUse, parameter, targetType, converterType);
          }
          else {
            body = getAdvice().handleEmptyBody(null, message, parameter, targetType, converterType);
          }
          break;
        }
      }
  }
}