Java 用户类定义：属性私有化，提供 set/get 方法和 showInfo() 方法

public class User {\n private int userID;\n private String password;\n private String emailAddress;\n\n public int getUserID() {\n return userID;\n }\n\n public void setUserID(int userID) {\n this.userID = userID;\n }\n\n public String getPassword() {\n return password;\n }\n\n public void setPassword(String password) {\n this.password = password;\n }\n\n public String getEmailAddress() {\n return emailAddress;\n }\n\n public void setEmailAddress(String emailAddress) {\n this.emailAddress = emailAddress;\n }\n\n public void showInfo() {\n System.out.println("User ID: " + userID);\n System.out.println("Password: " + password);\n System.out.println("Email Address: " + emailAddress);\n }\n\n public static void main(String[] args) {\n User user = new User();\n user.setUserID(123);\n user.setPassword("password123");\n user.setEmailAddress("example@example.com");\n\n user.showInfo();\n }\n}