问题描述
如何在JAVA中检查variables of Objects
是empty or NULL
?
Employee employee = repository.getEmployee(id).orElseGet(null);
if (employee == null) {
employee = new Employee();
employee.id(1);
employee.name("Thirumal");
employee.mobile("+91-8973-697-871");
repository.save(employee);
}
我正在尝试创建对象NULL
而不是new Employee()
Employee employee = repository.getEmployee(id).orElseGet(new Employee());
if (employee.isEmpty()) { //--------- How to do ????????
employee = new Employee();
employee.id(1);
employee.name("Thirumal");
employee.mobile("+91-8973-697-871");
repository.save(employee);
}
如何检查member of objects
是否是empty/NULL
?
解决方法
只需将isEmpty
方法添加到Employee
类中并在其中实现,或者使用null object pattern而不是进行new Employee()
。
关于您实际上在代码中尝试执行的操作,我建议改为这样做:
Employee employee = repository.getEmployee(id).orElseGet(() -> {
Employee emp = new Employee();
emp.id(1);
emp.name("Thirumal");
emp.mobile("+91-8973-697-871");
return repository.save(emp);
});