Java 密码生成器

generator java passwords

2022-09-01 21:28:51

我正在尝试创建一个java程序来创建密码，无论是全部小写，小写和大写，小写和大写和数字，小写和大写，数字和标点符号，程序还必须创建一个用户选择的密码，并且必须根据用户选择的内容生成密码长度。我已经生成了密码选项供用户选择，并提示他选择一个。我现在被困在如何创建上面提到的密码类型上。一个人建议我使用ASCII值，然后将其转换为文本。我知道如何将它们转换为文本，但它将显示数字，字母和标点符号。有没有办法只为小写字母生成ASCII值？另外，我将如何根据用户给出的长度生成密码？

答案 1

我使用这个不可变类。
它使用生成器模式。
它不支持扩展。

public final class PasswordGenerator {

    private static final String LOWER = "abcdefghijklmnopqrstuvwxyz";
    private static final String UPPER = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    private static final String DIGITS = "0123456789";
    private static final String PUNCTUATION = "!@#$%&*()_+-=[]|,./?><";
    private boolean useLower;
    private boolean useUpper;
    private boolean useDigits;
    private boolean usePunctuation;

    private PasswordGenerator() {
        throw new UnsupportedOperationException("Empty constructor is not supported.");
    }

    private PasswordGenerator(PasswordGeneratorBuilder builder) {
        this.useLower = builder.useLower;
        this.useUpper = builder.useUpper;
        this.useDigits = builder.useDigits;
        this.usePunctuation = builder.usePunctuation;
    }

    public static class PasswordGeneratorBuilder {

        private boolean useLower;
        private boolean useUpper;
        private boolean useDigits;
        private boolean usePunctuation;

        public PasswordGeneratorBuilder() {
            this.useLower = false;
            this.useUpper = false;
            this.useDigits = false;
            this.usePunctuation = false;
        }

        /**
         * Set true in case you would like to include lower characters
         * (abc...xyz). Default false.
         *
         * @param useLower true in case you would like to include lower
         * characters (abc...xyz). Default false.
         * @return the builder for chaining.
         */
        public PasswordGeneratorBuilder useLower(boolean useLower) {
            this.useLower = useLower;
            return this;
        }

        /**
         * Set true in case you would like to include upper characters
         * (ABC...XYZ). Default false.
         *
         * @param useUpper true in case you would like to include upper
         * characters (ABC...XYZ). Default false.
         * @return the builder for chaining.
         */
        public PasswordGeneratorBuilder useUpper(boolean useUpper) {
            this.useUpper = useUpper;
            return this;
        }

        /**
         * Set true in case you would like to include digit characters (123..).
         * Default false.
         *
         * @param useDigits true in case you would like to include digit
         * characters (123..). Default false.
         * @return the builder for chaining.
         */
        public PasswordGeneratorBuilder useDigits(boolean useDigits) {
            this.useDigits = useDigits;
            return this;
        }

        /**
         * Set true in case you would like to include punctuation characters
         * (!@#..). Default false.
         *
         * @param usePunctuation true in case you would like to include
         * punctuation characters (!@#..). Default false.
         * @return the builder for chaining.
         */
        public PasswordGeneratorBuilder usePunctuation(boolean usePunctuation) {
            this.usePunctuation = usePunctuation;
            return this;
        }

        /**
         * Get an object to use.
         *
         * @return the {@link gr.idrymavmela.business.lib.PasswordGenerator}
         * object.
         */
        public PasswordGenerator build() {
            return new PasswordGenerator(this);
        }
    }

    /**
     * This method will generate a password depending the use* properties you
     * define. It will use the categories with a probability. It is not sure
     * that all of the defined categories will be used.
     *
     * @param length the length of the password you would like to generate.
     * @return a password that uses the categories you define when constructing
     * the object with a probability.
     */
    public String generate(int length) {
        // Argument Validation.
        if (length <= 0) {
            return "";
        }

        // Variables.
        StringBuilder password = new StringBuilder(length);
        Random random = new Random(System.nanoTime());

        // Collect the categories to use.
        List<String> charCategories = new ArrayList<>(4);
        if (useLower) {
            charCategories.add(LOWER);
        }
        if (useUpper) {
            charCategories.add(UPPER);
        }
        if (useDigits) {
            charCategories.add(DIGITS);
        }
        if (usePunctuation) {
            charCategories.add(PUNCTUATION);
        }

        // Build the password.
        for (int i = 0; i < length; i++) {
            String charCategory = charCategories.get(random.nextInt(charCategories.size()));
            int position = random.nextInt(charCategory.length());
            password.append(charCategory.charAt(position));
        }
        return new String(password);
    }
}

这是一个用法示例，

PasswordGenerator passwordGenerator = new PasswordGenerator.PasswordGeneratorBuilder()
        .useDigits(true)
        .useLower(true)
        .useUpper(true)
        .build();
String password = passwordGenerator.generate(8); // output ex.: lrU12fmM 75iwI90o

答案 2

您可以使用来生成随机文本/密码。例如，请参阅此链接。org.apache.commons.lang.RandomStringUtils