JAVA获得包含0-9、a-z、A-Z范围内字符串的的随机数实例

/**
* JAVA获得0-9,A-Z范围的随机数
* @param length 随机数长度
* @return String
*/
public static String getRandomChar(int length) {
char[] chr = {'0','1','2','3','4','5','6','7','8','9',
'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
Random random = new Random();
StringBuffer buffer = new StringBuffer();
for (int i = 0; i < length; i++) {
buffer.append(chr[random.nextInt(62)]);
}
return buffer.toString();
}
public static String getRandomChar() {
return getRandomChar(10);
}

/**
* JAVA获得0-9的随机数 长度默认为10
*
* @return String
*/
public static String getRandomNumber() {
return getRandomNumber(10);
}

/**
* JAVA获得0-9的随机数
*
* @param length
* @return String
*/
public static String getRandomNumber(int length) {
Random random = new Random();
StringBuffer buffer = new StringBuffer();
for (int i = 0; i < length; i++) {
buffer.append(random.nextInt(10));
}
return buffer.toString();
}