Java密码生成器

Question

我正在尝试创建一个创建密码的java程序,全部是小写,小写和大写,小写和大写以及数字,小写和大写以及数字和标点符号,程序还必须创建用户选择的密码之一并且必须根据用户选择的内容生成密码长度.我已经为用户选择了密码选项,并提示他选择一个.我现在坚持如何创建上面提到的密码类型.一个人建议我使用ASCII值,然后将它们转换为文本.我知道如何将它们转换为文本,但它会显示数字,字母和标点符号.有没有什么办法可以只为小写字母生成ASCII值？另外我如何根据用户'生成密码'

Answer 1

我使用这个不可变类.
它使用构建器模式.
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

Answer 2

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

Answer 3

import java.security.SecureRandom;
import java.util.Random;

public class PasswordHelper {        

    public static String generatePassword (int length) {

    //minimum length of 6
    if (length < 4) {
        length = 6;
    }

    final char[] lowercase = "abcdefghijklmnopqrstuvwxyz".toCharArray();
    final char[] uppercase = "ABCDEFGJKLMNPRSTUVWXYZ".toCharArray();
    final char[] numbers = "0123456789".toCharArray();
    final char[] symbols = "^$?!@#%&".toCharArray();
    final char[] allAllowed = "abcdefghijklmnopqrstuvwxyzABCDEFGJKLMNPRSTUVWXYZ0123456789^$?!@#%&".toCharArray();

    //Use cryptographically secure random number generator
    Random random = new SecureRandom();

    StringBuilder password = new StringBuilder(); 

    for (int i = 0; i < length-4; i++) {
        password.append(allAllowed[random.nextInt(allAllowed.length)]);
    }

    //Ensure password policy is met by inserting required random chars in random positions
    password.insert(random.nextInt(password.length()), lowercase[random.nextInt(lowercase.length)]);
    password.insert(random.nextInt(password.length()), uppercase[random.nextInt(uppercase.length)]);
    password.insert(random.nextInt(password.length()), numbers[random.nextInt(numbers.length)]);
    password.insert(random.nextInt(password.length()), symbols[random.nextInt(symbols.length)]);
    }

    return password.toString();

    }

}

Answer 4

以防万一对某人有用。标准Java 8类基于ASCII范围的单行随机密码生成器：

String password = new Random().ints(10, 33, 122).collect(StringBuilder::new,
        StringBuilder::appendCodePoint, StringBuilder::append)
        .toString();

要么

String password = new Random().ints(10, 33, 122).mapToObj(i -> String.valueOf((char)i)).collect(Collectors.joining());

这里的密码长度为10。当然，您也可以在一定范围内随机设置它。并且这些字符来自ASCII范围33-122，它们都是特殊符号，数字大小写。

如果只需要小写字母，则可以设置范围：97-122

Answer 5

您可以随机选择具有尺寸的数字、字母和标点符号。Ansii 数字为 30 到 39，小写字母为 61-7A，ans 依此类推。使用ansii表