小编use*_*293的帖子

对于我的JavaFx应用程序,我想检查TextField是否为空,如果是,则提醒用户.这些是TextFields:

VBox fields = new VBox();  
Text usernametext = new Text("User name");
TextField user_name = new TextField();
Text firstnametext = new Text("First name");
TextField first_name = new TextField();
Text lastnametext = new Text("Last name");
TextField last_name = new TextField();
Text ibantext = new Text("IBAN");
TextField iban = new TextField();
Text passwordtext = new Text("Password");
TextField password = new TextField();
Text confirmpasstext = new Text("Confirm password");
TextField confirmpass = new TextField();
Button createBtn = new Button("Create account");

现在我只想在一个文本字段上测试验证.这是我的验证函数,它链接到createBtn:

public void validation(){ …

奇怪的是,有时BeautifulSoup对象确实提供了所需的数据,但有时我得到的错误就像or listindex error或out of rangeor nonetype object does not have attribute findNext(),这是嵌套在其他元素中的数据.

这是代码:

url = 'http://www.computerstore.nl/product/470130/category-208983/asrock-z97-extreme6.html'
source_code = requests.get(url)
plain_text = source_code.text
soup = BeautifulSoup(plain_text)

a = soup.find(text=('Socket')).find_next('dd').string

print(a)

尝试运行此代码时:

List<Users> list = em.createQuery("select balance b from Users where b.userName = '" + user_name.getText() +"'", Users.class).getResultList();

我遇到此错误消息:

语法错误解析[从用户中选择余额b,其中b.userName ='a'].[28,28]必须为范围变量声明提供标识变量.

我想从user_name TextField中键入其名称的User检索Integer余额.我是这个主题的初学者,互联网提供了复杂的信息.有人可以请解释一下有什么问题吗？

Users类的一部分

@Entity
@Table(name = "users")
@XmlRootElement
@NamedQueries({
@NamedQuery(name = "Users.findAll", query = "SELECT u FROM Users u"),
@NamedQuery(name = "Users.findByUserName", query = "SELECT u FROM Users u WHERE u.userName = :userName"),
@NamedQuery(name = "Users.findByBalance", query = "SELECT u FROM Users u WHERE u.balance = :balance"),
@NamedQuery(name = "Users.findByFirstName", query = "SELECT u FROM Users u WHERE u.firstName = …

因此，我建立了一个github项目并将其链接到Jenkins，但是每当我执行构建尝试时，它都会在控制台中显示：

C:\Program Files (x86)\Jenkins\workspace\SYS-ictlab>mocha
'mocha' is not recognized as an internal or external command,
operable program or batch file.

我错过了什么？

提前致谢