Thanks the answer of @jkee .
Here is my solution.
First, a custom annotation:
@Inherited
@Documented
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface ParamName {
/**
* The name of the request parameter to bind to.
*/
String value();
}
A customer DataBinder:
public class ParamNameDataBinder extends ExtendedServletRequestDataBinder {
private final Map<String, String> paramMappings;
public ParamNameDataBinder(Object target, String objectName, Map<String, String> paramMappings) {
super(target, objectName);
this.paramMappings = paramMappings;
}
@Override
protected void addBindValues(MutablePropertyValues mutablePropertyValues, ServletRequest request) {
super.addBindValues(mutablePropertyValues, request);
for (Map.Entry<String, String> entry : paramMappings.entrySet()) {
String paramName = entry.getKey();
String fieldName = entry.getValue();
if (mutablePropertyValues.contains(paramName)) {
mutablePropertyValues.add(fieldName, mutablePropertyValues.getPropertyValue(paramName).getValue());
}
}
}
}
A parameter resolver:
public class ParamNameProcessor extends ServletModelAttributeMethodProcessor {
@Autowired
private RequestMappingHandlerAdapter requestMappingHandlerAdapter;
private static final Map<Class<?>, Map<String, String>> PARAM_MAPPINGS_CACHE = new ConcurrentHashMap<>(256);
public ParamNameProcessor() {
super(false);
}
@Override
public boolean supportsParameter(MethodParameter parameter) {
return parameter.hasParameterAnnotation(RequestParam.class)
&& !BeanUtils.isSimpleProperty(parameter.getParameterType())
&& Arrays.stream(parameter.getParameterType().getDeclaredFields())
.anyMatch(field -> field.getAnnotation(ParamName.class) != null);
}
@Override
protected void bindRequestParameters(WebDataBinder binder, NativeWebRequest nativeWebRequest) {
Object target = binder.getTarget();
Map<String, String> paramMappings = this.getParamMappings(target.getClass());
ParamNameDataBinder paramNameDataBinder = new ParamNameDataBinder(target, binder.getObjectName(), paramMappings);
requestMappingHandlerAdapter.getWebBindingInitializer().initBinder(paramNameDataBinder, nativeWebRequest);
super.bindRequestParameters(paramNameDataBinder, nativeWebRequest);
}
/**
* Get param mappings.
* Cache param mappings in memory.
*
* @param targetClass
* @return {@link Map<String, String>}
*/
private Map<String, String> getParamMappings(Class<?> targetClass) {
if (PARAM_MAPPINGS_CACHE.containsKey(targetClass)) {
return PARAM_MAPPINGS_CACHE.get(targetClass);
}
Field[] fields = targetClass.getDeclaredFields();
Map<String, String> paramMappings = new HashMap<>(32);
for (Field field : fields) {
ParamName paramName = field.getAnnotation(ParamName.class);
if (paramName != null && !paramName.value().isEmpty()) {
paramMappings.put(paramName.value(), field.getName());
}
}
PARAM_MAPPINGS_CACHE.put(targetClass, paramMappings);
return paramMappings;
}
}
Finally, a bean configuration for adding ParamNameProcessor into the first of argument resolvers:
@Configuration
public class WebConfig {
/**
* Processor for annotation {@link ParamName}.
*
* @return ParamNameProcessor
*/
@Bean
protected ParamNameProcessor paramNameProcessor() {
return new ParamNameProcessor();
}
/**
* Custom {@link BeanPostProcessor} for adding {@link ParamNameProcessor} into the first of
* {@link RequestMappingHandlerAdapter#argumentResolvers}.
*
* @return BeanPostProcessor
*/
@Bean
public BeanPostProcessor beanPostProcessor() {
return new BeanPostProcessor() {
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
return bean;
}
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
if (bean instanceof RequestMappingHandlerAdapter) {
RequestMappingHandlerAdapter adapter = (RequestMappingHandlerAdapter) bean;
List<HandlerMethodArgumentResolver> argumentResolvers = new ArrayList<>(adapter.getArgumentResolvers());
argumentResolvers.add(0, paramNameProcessor());
adapter.setArgumentResolvers(argumentResolvers);
}
return bean;
}
};
}
}
Param pojo:
@Data
public class Foo {
private Integer id;
@ParamName("first_name")
private String firstName;
@ParamName("last_name")
private String lastName;
@ParamName("created_at")
@DateTimeFormat(pattern = "yyyy-MM-dd")
private Date createdAt;
}
Controller method:
@GetMapping("/foos")
public ResponseEntity<List<Foo>> listFoos(@RequestParam Foo foo, @PageableDefault(sort = "id") Pageable pageable) {
List<Foo> foos = fooService.listFoos(foo, pageable);
return ResponseEntity.ok(foos);
}
That's all.
