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[Java教程]工具类:获得随机字母和数字的组合(字母+数字组合,字母组合,数字组合)


package util;import java.util.Random;/** * * @author jkfeng * 获得随机字母和数字的组合(字母+数字组合,字母组合,数字组合) * */public class RandomCharOrNumUtil {	public static void main(String[] args) {		System.out.println(getCharAndNum(6));		System.out.println(getChar(6));		System.out.println(getNum(6));	}	/**	 * 获得随机子母和数字的组合	 * @param length	 * @return 随机字母和数字的组合	 */	public static String getCharAndNum(int length) {		String val = "";		Random random = new Random();		String charOrNum = "";		for (int i = 0; i < length; i++) {			if (i == 0) {				charOrNum = "char";			}else if (i == (length-1)) {				charOrNum = "num";			}else {				charOrNum = (random.nextInt(2)%2 == 0) ? "char":"num";			}			if ("num".equalsIgnoreCase(charOrNum)) {//如何获得 0-9之间的数字				int num = random.nextInt(10);				if (num == 0) {					num = 2;				}				if (num == 1) {					num = 5;				}				val += String.valueOf(num);			}else {//如何获得随机的字符				//97 - 122  0-25				char char1 = (char)(97+random.nextInt(26));				if (char1 == 'o') {					char1 = 'm';				}				val += String.valueOf(char1);			}		}		val = val.toUpperCase();		return val;		 	}		/**	 * 获得随机字母组合	 * @param length	 * @return 随机字母组合	 */	public static String getChar(int length) {		String val = "";		Random random = new Random();		for (int i = 0; i < length; i++) {			//如何获得随机的字符				//97 - 122  0-25			char char1 = (char)(97+random.nextInt(26));			val += String.valueOf(char1);		}		val = val.toUpperCase();		return val; 	}		/**	 * 获得随机数字组合	 * @param length	 * @return 随机数字组合	 */	public static String getNum(int length) {		String val = "";		Random random = new Random();		for (int i = 0; i < length; i++) {//如何获得 0-9之间的数字			int num = random.nextInt(10);			val += String.valueOf(num);		}		val = val.toUpperCase();		return val; 	}}