贴一个我自己用的方案吧，这个的缺点是 Response 如果是非成功状态抛出异常是会被 feign 捕获包装重新抛出，里面包含了 decode 的信息。
public class AutoBoxingDecoder implements Decoder {
private final SpringDecoder delegate;
public AutoBoxingDecoder(SpringDecoder decoder) {
this.delegate = decoder;
}
@
Override public Object decode(Response response, Type type) throws IOException, FeignException {
if (type instanceof NormalResponse) {
return delegate.decode(response,type);
} else if (type instanceof ParameterizedType) {
ParameterizedType t = (ParameterizedType) type;
if (t.getRawType() instanceof NormalResponse) {
return delegate.decode(response,type);
}
}
ParameterizedType pt = new MyParameterizedType(type);
Object object = delegate.decode(response,pt);
if (object instanceof NormalResponse) {
return unpackOrThrow((NormalResponse<?>) object);
}
return object;
}
private Object unpackOrThrow(NormalResponse<?> res) {
if (res == null) {
throw new AppException("client response body is empty.");
}
if (!res.isSuccess()) {
throw new AppException(res.getMessage());
}
return res.getData();
}
static class MyParameterizedType implements ParameterizedType {
private final Type argument;
MyParameterizedType(Type argument) {
this.argument = argument;
}
@
Override public Type[] getActualTypeArguments() {
return new Type[]{argument};
}
@
Override public Type getRawType() {
return NormalResponse.class;
}
@
Override public Type getOwnerType() {
return null;
}
}
}