springboot入参出参下划线转驼峰
前言
因为历史原因前端入参和出参都为下划线，下划线对有亿点强迫症的我来说是不可接受的。因此就有了下面这篇。
本篇基于之前的一篇springboot封装统一返回 - Scott_pb - 博客园 (cnblogs.com)
引入xml
因为是基于jackson而spring-boot-starter-web已经包含
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
工具类
public class JsonUtils {
private static final ObjectMapper objectMapper = new ObjectMapper();
/**
* json字符串转驼峰
*
* @param json String
* @return String
*/
public static String convertToCamelCaseJson(String json) throws JsonProcessingException {
JsonNode jsonNode = objectMapper.readTree(json);
jsonNode = convertKeysToCamelCase(jsonNode);
return objectMapper.writeValueAsString(jsonNode);
}
/**
* JsonNode的key转驼峰
*
* @param jsonNode JsonNode
* @return JsonNode
*/
public static JsonNode convertKeysToCamelCase(JsonNode jsonNode) {
if (jsonNode.isObject()) {
ObjectNode objectNode = objectMapper.createObjectNode();
jsonNode.fields().forEachRemaining(entry -> {
objectNode.set(snakeToCamel(entry.getKey()), convertKeysToCamelCase(entry.getValue()));
});
return objectNode;
}
if (jsonNode.isArray()) {
ArrayNode arrayNode = objectMapper.createArrayNode();
jsonNode.elements().forEachRemaining(entry -> {
arrayNode.add(convertKeysToCamelCase(entry));
});
return arrayNode;
}
return jsonNode;
}
public static JsonNode convertKeysToSnake(JsonNode jsonNode) {
if (jsonNode.isObject()) {
ObjectNode objectNode = objectMapper.createObjectNode();
jsonNode.fields().forEachRemaining(entry -> {
objectNode.set(camelToSnake(entry.getKey()), convertKeysToCamelCase(entry.getValue()));
});
return objectNode;
}
if (jsonNode.isArray()) {
ArrayNode arrayNode = objectMapper.createArrayNode();
jsonNode.elements().forEachRemaining(entry -> {
arrayNode.add(convertKeysToSnake(entry));
});
return arrayNode;
}
return jsonNode;
}
/**
* 下划线转驼峰
*
* @param key String
* @return String
*/
public static String snakeToCamel(String key) {
if (key.indexOf("_") != 0) {
String[] s = key.split("_");
StringBuilder stringBuilder = new StringBuilder(s[0]);
for (int i = 1; i < s.length; i++) {
stringBuilder.append(s[i].substring(0, 1).toUpperCase()).
append(s[i].substring(1));
}
return stringBuilder.toString();
}
return key;
}
/**
* 驼峰转下划线
* @param key String
* @return String
*/
public static String camelToSnake(String key) {
int length = key.length();
StringBuilder sb = new StringBuilder(length);
for (int i = 0; i < length; i++) {
char current = key.charAt(i);
if (Character.isUpperCase(current)) {
if (i > 0) {
sb.append('_');
}
sb.append(Character.toLowerCase(current));
continue;
}
sb.append(current);
}
return sb.toString();
}
}
ServletRequest定义
因为requestBody是流形式，所以转驼峰后，需要将转后的数据封装为流到requestBody中,我采用继承HttpServletRequestWrapper的方法重写HttpServletRequest
public class CamelKeyRequestWrapper extends HttpServletRequestWrapper {
//修改后的字节数组
private final byte[] modifiedContent;
//json的key转为驼峰
public CamelKeyRequestWrapper(HttpServletRequest request) throws IOException {
super(request);
this.modifiedContent = camelCaseJson(request);
}
//调用getInputStream时，返回转化后的驼峰json数据
public ServletInputStream getInputStream() {
return new ModifiedServletInputStream(new ByteArrayInputStream(modifiedContent));
}
@Override
public BufferedReader getReader() {
return new BufferedReader(new InputStreamReader(getInputStream()));
}
/**
* 下划线转驼峰
* @param request HttpServletRequest
* @return byte[]
* @throws IOException e
*/
private byte[] camelCaseJson(HttpServletRequest request) throws IOException {
//没有requestBody
if (request.getContentType() != null && !request.getContentType().contains("application/json")) {
return null;
}
ServletInputStream inputStream = null;
BufferedReader reader = null;
String originalJsonBody, camelCaseJson = null;
ContentCachingRequestWrapper requestWrapper;
try {
requestWrapper = new ContentCachingRequestWrapper(request);
//原来的InputStream流，因为是流，所以只能使用一次
inputStream = requestWrapper.getInputStream();
//从流中按照UTF-8格式读取
reader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8));
//定义StringBuilder
StringBuilder stringBuilder = new StringBuilder();
String line;
//按行读取
while ((line = reader.readLine()) != null) {
stringBuilder.append(line);
}
//得到下划线的json字符串
originalJsonBody = stringBuilder.toString();
//将下划线的json字符串转为驼峰的json字符串
camelCaseJson = JsonUtils.convertToCamelCaseJson(originalJsonBody);
} catch (Exception e) {
e.printStackTrace();
} finally {
//不要忘了关闭链接
assert inputStream != null;
inputStream.close();
assert reader != null;
reader.close();
}
assert camelCaseJson != null;
return camelCaseJson.getBytes();
}
}
filter拦截器
@Component
@Order(1)
public class RequestBodyFilter implements Filter {
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
//判断有requestbody传入
if (servletRequest.getContentType() == null || !servletRequest.getContentType().contains("application/json")) {
filterChain.doFilter(servletRequest,servletResponse);
return;
}
//下划线转驼峰requestBody
filterChain.doFilter(new CamelKeyRequestWrapper((HttpServletRequest) servletRequest),servletResponse);
}
}
修改ResponseResultHandler
修改上一篇中ResponseResultHandler
@ControllerAdvice
public class ResponseResultHandler<T> implements ResponseBodyAdvice<Object> {
public static final String RESPONSE_RESULT_ANN = "RESPONSE-RESULT-ANN";
@Override
public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
ServletRequestAttributes sra = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
if (sra == null) {
return false;
}
HttpServletRequest sraRequest = sra.getRequest();
ResponseResult responseResult = (ResponseResult) sraRequest.getAttribute(RESPONSE_RESULT_ANN);
return responseResult != null;
}
@SneakyThrows
@Override
public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType,
Class<? extends HttpMessageConverter<?>> selectedConverterType,
ServerHttpRequest request, ServerHttpResponse response) {
if (body instanceof Response) {
return body;
}
//List数组
if (body instanceof List) {
body = converSnakeList((List<T>) body);
}
//PageInfoVo
if (body instanceof PageInfoVo) {
List<? extends T> snakeList = converSnakeList((List<T>) ((PageInfoVo<?>) body).getData());
((PageInfoVo<T>) body).setData(snakeList);
}
//...其他类型...
if (body instanceof String) {
return Response.success(body);
}
return Response.success(body);
}
/**
* 数组的key转为下划线
* @param data List
* @return List<? extends T>
* @throws JsonProcessingException JsonProcessingException
*/
private List<? extends T> converSnakeList(List<T> data) throws JsonProcessingException {
int size = data.size();
//list中有数据
if (size > 0) {
ObjectMapper objectMapper = new ObjectMapper();
List<JsonNode> snakeList = new ArrayList<>(size);
for (T datum : data) {
//object转JsonNode
JsonNode jsonNode = objectMapper.readTree(objectMapper.writeValueAsString(datum));
//JsonNode的key转为蛇形
JsonNode snakeJsonNode = JsonUtils.convertKeysToSnake(jsonNode);
snakeList.add(snakeJsonNode);
}
return (List<? extends T>) snakeList;
}
return null;
}
}