note: field in metedata is CamelCase , but dbfile is Underscore

[allenzs]

@JSONField(name = "ip_version")
public int IPVersion;
@JSONField(name = "node_count")
public int nodeCount;
public Map<String, Integer> Languages;
public String[] Fields;
@JSONField(name = "total_size")
public int totalSize;

[allenzs]

net.ipip.ipdb.InvalidDatabaseException: database file size error