Question

import java.awt.Component;

导入javax.swing.JOptionPane;

公共课DoSomething {

public static void main（String [] args）{

String password = JOptionPane.showInputDialog(null, 
"Please enter a password: "); 


    boolean number = false; 
    boolean character = false; 
    boolean symbol = false; 
    boolean length = false; 
    Component frame = null; 
    int counter = 0; 

char [] letters = password.toCharArray(); 
for (char c: letters){


if(Character.isLetter(c)) {
    if (password.matches("a-zA-Z")) {
        counter++;
        character= true;
    }
}

if(Character.isLetterOrDigit(c)) {
    counter++;
    symbol = false;
}

if(Character.isDigit(c)) {
    counter++; 
    if (counter >=2) {
        number = true;
    }
 if (password.length()>=8) {
    length = true;
        }







if (character && length && number && !symbol){
 JOptionPane.showMessageDialog("Your Password " +password +" is valid")
 }

编辑 - 它仍然讨厌长度（即使它是8或更多）

Answer 1

为什么不使用正则表达式？

public static boolean isValid(String password) {
    return password.matches("([a-zA-Z]{8,})([0-9]{2,})");
}

如果密码中有两个以上的数字，则此表达式（如果我没有记错的话）检查是否有8个或更多字符（小写和大写）和。 $，@，[space]等符号会将表达式触发为false。 编辑：此正则表达式仅允许包含8个（或更多）分组字符和2个（或更多）数字的密码。数字不能分开（1MyPassword3），因为这会将密码标记为无效。需要进一步调查。

请参阅java API了解正则表达式：

java 7 Pattern class

java 8 Pattern class

另请查看String.matches(String regex)

对评论作出反应

这段代码应该更适合你：

int letterCount = 0;
int numberCount = 0;

/*
 * Loop through the password and count all the letters and characters
 */
for (int i = 0; i < password.length(); i++) {
    char c = password.charAt(i);

    if (Character.toString(c).matches("[a-zA-Z]")) {
        letterCount++;
    }

    if (Character.toString(c).matches("[0-9]")) {
        numberCount++;
    }
}


if (letterCount > 8) {
    // password has 8 or more characters
}

if (numberCount > 2) {
    // password has more than 2 numbers
}

然后，如果你真的想检查长度，你可以添加这段代码（在for循环之外）

if (password.length() >= 10) {
    /* Since we need 2 numbers and 8 characters, the password
     * can never be valid if it's smaller than 10 characters
     */
else {
    /*
     * Invalid password
     */
}

Answer 2

假设您输入有效密码的条件为：

至少8个字母
至少2个数字
没有符号
至少10个字符

String password = JOptionPane.showInputDialog(null, "Please enter a password: "); 

boolean number = false; 
boolean character = false; 
boolean symbol = false; 
boolean length = false;  
int letterCounter = 0; 
int numCounter = 0;

Component frame = null; 

char [] letters = password.toCharArray(); 

for (char c: letters){
    if(Character.isLetter(c)) {
        letterCounter++;
    }
    else if(Character.isDigit(c)) {
        numCounter++;
    }
    else {
        symbol = true;
    }
}

//Checking booleans
if (password.length()>=10) {
    length = true;
}
if (letterCounter>=8) {
    character = true;
}
if (numCounter>=2) {
    number = true;
}

if (character && length && number && !symbol){
    JOptionPane.showMessageDialog(frame, "Your Password " + password + " is valid");
    System.out.println("Success");
}
else {
    System.out.println("Invalid");
}

密码验证（8个字母，2个数字，无符号）

2 个答案: