passwordgenerator.java

基于Eclipse RCP开发的管理工具

 /*  
  * Copyright 2006 Marcel Schoffelmeer 
  * 
  * Licensed under the Apache License, Version 2.0 (the "License"); 
  * you may not use this file except in compliance with the License. 
  * You may obtain a copy of the License at 
  * 
  *    http://www.apache.org/licenses/LICENSE-2.0 
  *    
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

package com.s10r.util;

import java.util.Random;

public class PasswordGenerator
{
	public static final int NUMERIC = 1;
	public static final int UPPER_ALPHA = 2;
	public static final int LOWER_ALPHA = 4;
	public static final int SPECIAL = 8;
	public static final int BRACKET = 16;
	
	private static char[] NUMERIC_CHARS = new char[10];

	private static char[] UPPER_ALPHA_CHARS = new char[26];

	private static char[] LOWER_ALPHA_CHARS = new char[26];

	private static char[] SPECIAL_CHARS = new char[16];

	private static char[] BRACKET_CHARS = new char[] { '{', '}', '[', ']' };
		
	static
	{
		for (int i = 0; i < UPPER_ALPHA_CHARS.length; i++)
		{
			UPPER_ALPHA_CHARS[i] = (char) (65 + i);
			LOWER_ALPHA_CHARS[i] = (char) (97 + i);
		}
		for (int i = 0; i < NUMERIC_CHARS.length; i++)
		{
			NUMERIC_CHARS[i] = (char) (48 + i);
		}
		for (int i = 0; i < SPECIAL_CHARS.length; i++)
		{
			SPECIAL_CHARS[i] = (char) (33 + i);
		}
	}

	private char[] charSet = new char[300];
	private int charSetLength = 0;
	
	private char[] customChars;
	private Random RANDOM = new Random();
	
	// Note: DEFAULT must be instantiated after the static block
	// to make sure the individual char sets are initialized
    public static final PasswordGenerator DEFAULT =
    	new PasswordGenerator();
	
	public PasswordGenerator()
	{
		this(NUMERIC | UPPER_ALPHA | LOWER_ALPHA);
	}
	
	public PasswordGenerator(int selectedCharSets, char[] customChars)
	{		
		this.customChars = customChars;
		
		charSetLength = createCharSet(selectedCharSets);
	}
	
	public String generate(int length)
	{
		char[] newPass = new char[length];

		for (int i = 0; i < length; i++)
		{
			newPass[i] = charSet[RANDOM.nextInt(charSetLength)];
		}

	    String newPassStr = new String(newPass, 0, length);
	    return newPassStr;
	}

	public PasswordGenerator(int selectedCharSets)
	{
		this(selectedCharSets, null);
	}

	private int createCharSet(int selectedCharSets)
	{
		int start = 0;
		if ((selectedCharSets & UPPER_ALPHA) > 0)
		{
			copyCharsToCharSet(UPPER_ALPHA_CHARS, start);
			start = start + UPPER_ALPHA_CHARS.length;
		}
		if ((selectedCharSets & LOWER_ALPHA) > 0)
		{
			copyCharsToCharSet(LOWER_ALPHA_CHARS, start);
			start = start + LOWER_ALPHA_CHARS.length;
		}
		if ((selectedCharSets & NUMERIC) > 0)
		{
			copyCharsToCharSet(NUMERIC_CHARS, start);
			start = start + NUMERIC_CHARS.length;
		}
		if ((selectedCharSets & SPECIAL) > 0)
		{
			copyCharsToCharSet(SPECIAL_CHARS, start);
			start = start + SPECIAL_CHARS.length;
		}
		if ((selectedCharSets & BRACKET) > 0)
		{
			copyCharsToCharSet(BRACKET_CHARS, start);
			start = start + BRACKET_CHARS.length;
		}
		if (customChars != null && customChars.length > 0)
		{
			copyCharsToCharSet(customChars, start);
			start = start + customChars.length;
			
		}
		return start;
	};

	private void copyCharsToCharSet(char[] src, int charSetStart)
	{
		System.arraycopy(src, 0, charSet, charSetStart, src.length);
	}
	
}