使用Java显示随机图片

Question

I am trying to display random pictures based on Random() method's generation(just trying something like captcha). I am generating random no from an array, but dont know how to map these no's with images. Any ideas ? What I've done till now:

import java.util.Arrays; import java.util.Random;

public class Gen_Captcha {

static String[] myCaptchaLetters = {"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","0","1","2","3","4","5","6","7","8","9"};
Gen_Captcha captcha= new Gen_Captcha();
public static void main(String[] args) {
    Random randomGenerator = new Random();
    for(int i=0;i<5;i++){
        int random = randomGenerator.nextInt(62);
        System.out.print((myCaptchaLetters[random]));       
    }

}

}

}

Note: The above code does not include the swing framework code to display image.

Answer 1

Create a List<BufferedImage> , and use Collections.shuffle() to randomize the list. Using the list's iterator will visit the images randomly without duplicates.

Answer 2

but dont know how to map these no's with images

Don't map the numbers, map the letters:

Map<String, Image> images = new HashMap<String, Image>();
images.put("a", imageA);
images.put("b", imageB);

Answer 3

You might want to take a look at Graphics.drawString()

You can get a graphics2D object by creating a BufferedImage Note there are also methods to change the font. for more advanced captcha's you can then warp the image and draw random stuff on it as well using the same api's.