private Object decodeValue(String jsonString, Class<?> type)
			throws IOException, LinkageError {
		Object value = objectMapper.readValue(jsonString, type);
		if (type.equals(NonTrustedHeaderType.class)) {
			// Upstream NTHT propagated; may be trusted here...
			NonTrustedHeaderType nth = (NonTrustedHeaderType) value;
			if (trusted(nth.getUntrustedType())) {
				try {
					value = objectMapper.readValue(nth.getHeaderValue(),
							ClassUtils.forName(nth.getUntrustedType(), null));
				}
				catch (Exception e) {
					log.error("Could not decode header: " + nth, e);
				}
			}
		}
		return value;
	}
Add packages to the trusted packages list (default {@code java.util, java.lang})
used when constructing objects from JSON. If any of the supplied packages is
{@code "*"}, all packages are trusted. If a class for a non-trusted package is
encountered, the header is returned to the application with value of type
{@link NonTrustedHeaderType}.
@param packagesToTrust the packages to trust.
spring-cloud-alibaba-starters/spring-cloud-starter-stream-rocketmq/src/main/java/com/alibaba/cloud/stream/binder/rocketmq/support/JacksonRocketMQHeaderMapper.java