one:
package test;
import java.util.Scanner;
public class LibraryCardGeneration {
public static void main(String[] args) {
String userName;
String password;
System.out.println("************************");
System.out.println(" Welcome to OOP Library");
System.out.println("************************");
Scanner scanner = new Scanner(System.in);
// Read user name from standard input (Task: user name cannot be empty)
System.out.print("Please set your user name: ");
userName = scanner.nextLine();
// Read user password from standard input (Task: Ask the user to re-enter the password to reconfirm)
System.out.print("Please set your password: ");
password = scanner.nextLine();
// Create a new library card
LibraryCard newCard = new LibraryCard(userName,password);
System.out.println("Your library card is generated successfully!");
newCard.printLibraryCard();
scanner.close();
}
}
two:
package test;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.logging.Level;
import java.util.logging.Logger;
public class CryptWithMD5 {
private static MessageDigest md;
public static String cryptWithMD5(String pass){
try {
md = MessageDigest.getInstance("MD5");
byte[] passBytes = pass.getBytes();
md.reset();
byte[] digested = md.digest(passBytes);
StringBuffer sb = new StringBuffer();
for(int i=0;i<digested.length;i++){
sb.append(Integer.toHexString(0xff & digested[i]));
}
return sb.toString();
} catch (NoSuchAlgorithmException ex) {
Logger.getLogger(CryptWithMD5.class.getName()).log(Level.SEVERE, null, ex);
}
return null;
}
}
three:
package test;
public class LibraryCard {
private String userName;
private String cryptPassword;
//private Calendar dateOfApplication;
//private int borrowedNum;
public LibraryCard(String userName2, String password) {
userName = userName2;
cryptPassword = CryptWithMD5(password);
}
public void printLibraryCard()
{
System.out.println("----------------------------------------------------------");
System.out.println(" OOP Library Card ");
System.out.println("----------------------------------------------------------");
System.out.println("User name :"+ userName);
System.out.println("crypt Password :"+cryptPassword );
}
}
問題：
1.
cryptPassword = CryptWithMD5(password);
這句爲什麽無法調用 CryptWithMD5？
2.LibraryCard newCard = new LibraryCard(userName,password);
這個爲什麽顯示錯誤。。
運行結果顯示：
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
The method CryptWithMD5(String) is undefined for the type LibraryCard
at test.LibraryCard.<init>(LibraryCard.java:12)
at test.LibraryCardGeneration.main(LibraryCardGeneration.java:28) |
