我试图做一个if和else语句，如果datetimepicker为空，它将不接受进程，所以我尝试了这个语句，但它只是忽略了它，所以任何可能的方法我如何从这个datetimepicker获取值或文本？

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    if(dateTimePicker1.equals("") || dateTimePicker2.equals("") || jTextField1.getText().equals("PACKAGES OFFERED: ") 
            || jTextField5.getText().equals("FOOD SERVICES: ") || jTextField6.getText().equals("HOTEL ACTIVITIES: ")
            || jTextField7.getText().equals("HOTEL SERVICES: "))
    {
        jLabel8.setText("Invalid data please add valid data");
        jLabel8.setOpaque(true);
    }
    else{
        Hotel_Dashboard2 hd1 = new Hotel_Dashboard2();
        Hotel_Dashboard2.jLabel8.setText(Hotel_Dashboard1.jLabel9.getText());
        hd1.setVisible(true);
    }
}

以下是我尝试的代码：

if(dateTimePicker1=='' || dateTimePicker2.=='' 
if(dateTimePicker1.length===(0) || dateTimePicker2.length===(0)
if(dateTimePicker1==null || dateTimePicker2.equals==null