Implement PasswordBuilder

src/main/java/de/icaotix/generator/PasswordBuilder.java

@@ -0,0 +1,88 @@
+package de.icaotix.generator;
+
+import java.util.LinkedList;
+import java.util.Random;
+
+public class PasswordBuilder {
+    private static final String UPPERCASE_LETTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    private static final String LOWERCASE_LETTERS = UPPERCASE_LETTERS.toLowerCase();
+    private static final String NUMBERS = "1234567890";
+    private static final String SPECIAL_CHARACTERS = "~!@#()*^&%§?.,<>:/|[]{}=+_-";
+
+    private int length;
+    private int repeat;
+    private boolean appendUpper = true;
+    private boolean appendLower = true;
+    private boolean appendNumbers = true;
+    private boolean appendSpecial = false;
+    private String excludes;
+
+    public PasswordBuilder() {
+        this.length = 8;
+        this.repeat = 1;
+    }
+
+    public PasswordBuilder setLength(int length) {
+        this.length = length;
+        return this;
+    }
+
+    public PasswordBuilder setRepeat(int repeat) {
+        this.repeat = repeat;
+        return this;
+    }
+
+    public PasswordBuilder setExcludes(String excludes) {
+        this.excludes = excludes;
+        return this;
+    }
+
+    public PasswordBuilder useLowercase(boolean use) {
+        this.appendLower = use;
+        return this;
+    }
+
+    public PasswordBuilder useUppercase(boolean use) {
+        this.appendUpper = use;
+        return this;
+    }
+
+    public PasswordBuilder useNumbers(boolean use) {
+        this.appendNumbers = use;
+        return this;
+    }
+
+    public PasswordBuilder useSpecial(boolean use) {
+        this.appendSpecial = use;
+        return this;
+    }
+
+    public LinkedList<String> generate() {
+        final StringBuilder poolBuilder = new StringBuilder();
+
+        if (appendUpper) poolBuilder.append(UPPERCASE_LETTERS);
+        if (appendLower) poolBuilder.append(LOWERCASE_LETTERS);
+        if (appendNumbers) poolBuilder.append(NUMBERS);
+        if (appendSpecial) poolBuilder.append(SPECIAL_CHARACTERS);
+
+        String finalPool = poolBuilder.toString().replaceAll(excludes, "");
+        LinkedList<String> passwords = new LinkedList<>();
+        Random rand = new Random();
+
+        if (finalPool.length() < 1) return passwords;
+
+        for (int i = 0; i < repeat; i++) {
+            StringBuilder currPassword = new StringBuilder();
+            for (int j = 0; j < length; j++) {
+                currPassword.append(
+                        finalPool.charAt(
+                                rand.nextInt(finalPool.length())
+                        )
+                );
+            }
+            passwords.add(currPassword.toString());
+        }
+
+        return passwords;
+    }
+}