JsonDeserializer raises NPE if targetType is an array #869
Description
Spring-Kafka version: 2.2.0
The following code snippet produces an NPE (the error occurs with any array type, String[] is just used as an example here):
JsonDeserializer<String[]> deserializer = new JsonDeserializer<>(String[].class);
The stacktrace is as follows:
Exception in thread "main" java.lang.NullPointerException
at org.springframework.kafka.support.serializer.JsonDeserializer.addTargetPackageToTrusted(JsonDeserializer.java:299)
at org.springframework.kafka.support.serializer.JsonDeserializer.<init>(JsonDeserializer.java:180)
at org.springframework.kafka.support.serializer.JsonDeserializer.<init>(JsonDeserializer.java:142)
at org.springframework.kafka.support.serializer.JsonDeserializer.<init>(JsonDeserializer.java:130)
The error is caused in method addTargetPackageToTrusted because this.targetType.getPackage() returns null for array types:
private void addTargetPackageToTrusted() {
if (this.targetType != null) {
addTrustedPackages(this.targetType.getPackage().getName());
}
}
A possible fix could be as follows (this one would also work for arrays of primitive types, like int[]):
private void addTargetPackageToTrusted() {
if (this.targetType != null) {
Package targetPackage = resolvePackage(this.targetType);
if (targetPackage != null) {
addTrustedPackages(targetPackage.getName());
}
}
}
// this method might still return null if the provided type represents a primitive array type, as int[]
private Package resolvePackage(Class<?> type) {
return (type.isArray() ? type.getComponentType() : type).getPackage();
}