示例

public class ClassA {{
public void test () {
SimpleDateFormat sdf = new SimpleDateFormat();
}
}

解决方案
始终将 Locale 自变量添加到 SimpleDateFormat 变量声明中

public class ClassA {{
public void test () {
Locale loc = Locale.US ;
SimpleDateFormat sdf = new SimpleDateFormat("", loc);
}
}