随机字符串生成算法

IOS算法：

char data[NUMBER_OF_CHARS];

    for (int x=0;x<NUMBER_OF_CHARS;data[x++] = (char)('A' + (arc4random_uniform(26))));

    return [[NSString alloc] initWithBytes:data length:NUMBER_OF_CHARS encoding:NSUTF8StringEncoding];

 

JAVA实现：

 

给定一个字符集合，给定随机生成的字符串的长度，即可随机生成字符串；

比如{'a','.....,'z'}及长度5，则随机生成一个长度为5的字符串；

package xiazdong.util;

import java.util.Random;

/*根据给定的char集合，生成随机的字符串*/
public class StringWidthWeightRandom {
    private Random widthRandom = new Random();
    private int length;
    private char[] chars;
    private Random random = new Random();
    public StringWidthWeightRandom(char[] chars) {
        this.chars = chars;
    }

    //参数为生成的字符串的长度，根据给定的char集合生成字符串
    public String getNextString(int length){

        char[] data = new char[length];

        for(int i = 0;i < length;i++){
            int index = random.nextInt(chars.length);
            data[i] = chars[index];
        }
        String s = new String(data);
        return s;
    }


}

测试代码：

package test.com.sap.prd.util;

import junit.framework.TestCase;

import org.junit.Test;

import com.sap.prd.util.StringWidthWeightRandom;

public class StringWidthWeightRandomTest extends TestCase {

    @Test
    public void testGetNextString()throws Exception{
        StringWidthWeightRandom random = new StringWidthWeightRandom(new char[]{'A','B','C','D','E','F','G'});

        for(int i=1;i<10;i++){
            System.out.println(random.getNextString(i));
        }
    }
}

结果：

F
CC
EGE
CADA
CFBFC
DBBCFE
BFEADFA
FDEEDACE
EEFFGFBEG