static
fields that are of a non-thread-safe type.
When a static
field is accessed from an instance method or a non-synchronized block,
multiple threads can access that field.
This can lead to unspecified side effects, like exceptions and incorrect results.
Example:
class Sample {
private static final SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
String method() {
return df.format("");
}
}
You can specify which types should be considered not thread-safe. Only fields with these exact types or initialized with these exact types are reported, because there may exist thread-safe subclasses of these types.