求一个java密码随机生成程序
要求：同时含有大小写字母，数字，特殊字符但不含有空格，8到32位，最好长度作为一个参数可调整
import java.util.Random;
public class RandomPassword {
public static void main(String[] args) {
String password = getRandomPassword(8);
System.out.println(password);
}
//获取验证过的随机密码
public static String getRandomPassword(int len) {
String result = null;
/*if(len >= 6) {
for(result = makeRandomPassword(len);len >= 6;result = makeRandomPassword(len)){
if (result.matches(".*[a-z]{1,}.*") && result.matches(".*[A-Z]{1,}.*") && result.matches(".*\\d{1,}.*") && result.matches(".*[~!@#$%^&*\\.?]{1,}.*")) {
return result;
}
}
}*/
while(len>=6){
result = makeRandomPassword(len);
if (result.matches(".*[a-z]{1,}.*") && result.matches(".*[A-Z]{1,}.*") && result.matches(".*\\d{1,}.*") && result.matches(".*[~!@#$%^&*\\.?]{1,}.*")) {
return result;
}
result = makeRandomPassword(len);
}
return "长度不得少于6位!";
}
//随机密码生成
public static String makeRandomPassword(int len){
char charr[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890~!@#$%^&*.?".toCharArray();
//System.out.println("字符数组长度:" + charr.length); //可以看到调用此方法多少次
StringBuilder sb = new StringBuilder();
Random r = new Random();
for (int x = 0; x < len; ++x) {
sb.append(charr[r.nextInt(charr.length)]);
}
return sb.toString();
}
}
拿去随便改改
这个简单
class MyClass
private static Random rnd = new Random();
private String metachars = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ..."; //把你要的字符都写进去
public static String genPwd(int n)
{
String r = "";
for (int i = 0; i < n; i++) r += metachars.substring(rnd.nextInt(metachars.length() - 1), 1);
return r;
}
}
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
public class PwdGenTest {
public static void main(String[] args) {
PasswordGenerator pwdGen = new PasswordGenerator();
for(int i = 0; i<20; ++i)
{
System.out.println(pwdGen.getPassword(12));
}
}
}
class PasswordGenerator{
private int[] upperRange = {65, 90};
private int[] lowerRange = {97, 122};
private int[] digitalRange = {48,57};
private int[][] symbolRanges = {{33,47},{58,64}, {91,96}, {123,126}};
final static int CHAR_TYPE_UPPER = 0;
final static int CHAR_TYPE_LOWER = 1;
final static int CHAR_TYPE_DIGITAL = 2;
final static int CHAR_TYPE_SYMBOL = 3;
final static int[] CHAR_TYPES = {CHAR_TYPE_UPPER, CHAR_TYPE_LOWER, CHAR_TYPE_DIGITAL, CHAR_TYPE_SYMBOL};
final static int TYPE_COUNT = CHAR_TYPES.length;
private Random random = new Random();
public String getPassword(int length){
int leftLength = length;
List<Integer[]> typeLens = new ArrayList<Integer[]>();
int i;
for(i = 0; i < TYPE_COUNT - 1; ++i){
int len = random.nextInt(leftLength-(TYPE_COUNT-i-1));
typeLens.add(new Integer[]{CHAR_TYPES[i], len});
leftLength -= len;
}
typeLens.add(new Integer[]{CHAR_TYPES[i], leftLength});
int typeIndex = 0;
Integer[] typeLen;
StringBuilder builder = new StringBuilder();
for(i = 0; i < length; ++i){
typeIndex = random.nextInt(typeLens.size());
typeLen = typeLens.get(typeIndex);
switch(typeLen[0]){
case CHAR_TYPE_UPPER:
builder.append(getUpper());
break;
case CHAR_TYPE_LOWER:
builder.append(getLower());
break;
case CHAR_TYPE_DIGITAL:
builder.append(getDigital());
break;
default:
builder.append(getSymbol());
break;
}
--typeLen[1];
if(typeLen[1] == 0)
typeLens.remove(typeIndex);
}
return builder.toString();
}
private char getSymbol(){
int symbolRangeIndex = random.nextInt(symbolRanges.length);
return (char)(getRandomIntFromRange(symbolRanges[symbolRangeIndex][0], symbolRanges[symbolRangeIndex][1]));
}
private char getUpper(){
return (char)(getRandomIntFromRange(upperRange[0], upperRange[1]));
}
private char getLower(){
return (char)(getRandomIntFromRange(lowerRange[0], lowerRange[1]));
}
private char getDigital(){
return (char)(getRandomIntFromRange(digitalRange[0], digitalRange[1]));
}
private int getRandomIntFromRange(int min, int max){
return random.nextInt(max)%(max-min+1) + min;
}
}
自己写的，可能有更好的方法，但可以保证每次都全部包含你需要的字符种类，而且每种字符的位置长度随机。输出示例:
private static final byte INDEX_NUMBER = 0;
private static final byte INDEX_LETTER = 1;
private static final byte INDEX_SPECIAL_CHAR = 2;
/** 特殊符号 */
private static final char[] SPECIAL_CHARS = {'`','~','!','@','#','$','%','^','&','*','(',')','-','_','=','+','[',']','{','}','\\','|',';',':','\'','"',',','<','.','>','/','?'};
public static void main(String[] args) {
int[] genChances = {1,2,3};
char[] password = generateRandomPassword(5,genChances);
System.out.println(password);
}
/**
* 按一定的概率生成一个随机的N位(N>=3)密码，必须由字母数字特殊符号组成，三者缺一不可
* @param len 密码长度,必须大于等于3
* @param genChances 分别是生成数字、字母、特殊符号的概率
* @return 生成的随机密码
*/
private static char[] generateRandomPassword(final int len,final int[] paramGenChances)throws IllegalArgumentException {
if (len < 3) {
throw new IllegalArgumentException("长度应该大于3");
}
final char[] password = new char[len];
// 之所以该复制一份是为了使函数不对外产生影响
final int[] genChances = paramGenChances.clone();
final int[] genNums = new int[genChances.length];
for (int i=0;i<genChances.length;i++){
genNums[i] = 0;
}
final Random random = new Random();
int r;
for (int i = 0; i < len; i++) {
adjustGenChance(len,i,genChances,genNums);
int index = getPasswordCharType(random,genChances);
genNums[index]++;
switch (index) {
case INDEX_NUMBER:
password[i] = (char) ('0' + random.nextInt(10));
break;
case INDEX_LETTER:
r = random.nextInt(52);
if (r < 26) {
password[i] = (char) ('A' + r);
} else {
password[i] = (char) ('a' + r - 26);
}
break;
case INDEX_SPECIAL_CHAR:
r = random.nextInt(SPECIAL_CHARS.length);
password[i] = SPECIAL_CHARS[r];
break;
default:
password[i] = ' ';
break;
}
}
return password;
}
/**
* 根据当前需要生成密码字符的位置,动态调整生成概率
* @param len 待生成的总长度
* @param index 当前位置
* @param genChances 分别是生成数字、字母、特殊符号的概率
* @param genNums 这些类型已经生成过的次数
*/
private static void adjustGenChance(final int len,final int index,final int[] genChances,final int[] genNums) {
final int leftCount = len - index;
byte notGenCount = 0;
for (int i = 0; i < genChances.length; i++) {
if (genNums[i] == 0) {
notGenCount++;
}
}
if (notGenCount > 0 && leftCount < genChances.length && leftCount == notGenCount) {
for (int i = 0; i < genChances.length; i++) {
if (genNums[i] > 0) {
genChances[i] = 0;
}
}
}
}
/**
* 获取该密码字符的类型
* @param random 随机数生成器
* @param genChances 分别是生成数字、字母、特殊符号的概率
* @return 密码字符的类型
*/
private static int getPasswordCharType(final Random random, final int[] genChances) {
int total = 0;
int i = 0;
for (; i < genChances.length; i++) {
total += genChances[i];
}
int r = random.nextInt(total);
for (i = 0; i < genChances.length; r -= genChances[i], i++) {
if (r < genChances[i]) {
break;
}
}
return i;
}
想偷懒就先生成随机数，然后md5
public String CreateNonceStr() {
int length = 16;
String chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
StringBuffer sb=new StringBuffer();
Random rad = new Random();
for (int i = 0; i < length; i++)
{
int number=rad.nextInt(chars.length());
sb.append(chars.charAt(number));
}
return sb.toString();
}