求一个java密码随机生成程序

Question

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

Answer 1

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