Java programming exercise: simulates User Logon using a layered structure based on XML files

The following XML file "user. xml" is used to store user logon information.

<?xml version="1.0" encoding="UTF-8"?><root><user id="u01" username="well" password="1234"/><user id="u02" username="lily" password="4321"/></root>

The hierarchical design concept is as follows:

Presentation Layer: LoginUI: input (): User LoginUI: output (): String

Business Layer: LoginBusiness: check (User): boolean

 

According to the above requirements, write the program:

(1) Compile the User class

package web.java.xml.exercise1;public class User {private String id;private String username;private String password;public String getId() {return id;}public void setId(String id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}}

 

(2) write the presentation layer LoginUI class, which is used to receive user input on the console and encapsulate it as a javaBean

package web.java.xml.exercise1;import java.util.Scanner;public class LoginUI {public User input(){User user = new User();Scanner scanner = new Scanner(System.in);System.out.print("username:");String username = scanner.nextLine();System.out.print("password:");String password = scanner.nextLine();user.setUsername(username);user.setPassword(password);return user;}public void output(boolean flag){if(flag){System.out.println("Login success!");} else {System.out.println("Login failed!");}}}

(3) write the LoginBusiness class at the business layer for User Login

package web.java.xml.exercise1;import java.io.File;import org.dom4j.Document;import org.dom4j.Element;import org.dom4j.io.SAXReader;public class LoginBusiness {public static void main(String[] args) throws Exception {LoginUI loginUI = new LoginUI();LoginBusiness loginBusiness = new LoginBusiness();User user = loginUI.input();boolean flag = loginBusiness.check(user);loginUI.output(flag);}public boolean check(User user) throws Exception {boolean flag = false;SAXReader saxReader = new SAXReader();File file = new File("src/web/java/xml/exercise1/users.xml");Document doc = saxReader.read(file);String xpath = "//user[@username='"+user.getUsername()+"' and @password='"+user.getPassword()+"']";Element ele = (Element) doc.selectSingleNode(xpath);if(ele!=null){flag = true;}return flag;}}