在Java中解析xml文档时出错

Question

我有以下代码：

public static void main(String[] args) 
    throws ParserConfigurationException, SAXException, IOException {

    DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
    dbFactory.setNamespaceAware(true);
    DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
    Document document = dBuilder.parse("NewFile.xml");
    String usr = document.getElementsByTagName("username").item(0).getTextContent();
    System.out.println(document);

}

这导致NullPointerException String usr行 <?xml version="1.0"?> <tudorTestUser> <propertySet> <property name="username">TudorTest123</property> <property name="firstName">Ion</property> <property name="lastName">Vasile</property> <property name="password">Tester123</property> <property name="passwordAgain">Tester123</property> <!-- <property name="location">Bucharest</property> --> <property name="email">tester@test.com</property> <property name="Status">active</property> <property name="thirdParty">No Third Party</property> <property name="agentID">Tester</property> <property name="switch">on</property> <property name="position">Web Master</property> <property name="clone"></property> <property name="overrideCode"></property> </propertySet> </tudorTe 。有什么想法吗？新文件放在工作区项目文件夹中，我也尝试给绝对路径没有成功。

XML文件：

@Column( nullable = true )
@JsonFormat( pattern = "yyyy-MM-dd HH:mm:ss" )
private Date        dateSysteme;