java生成随机验证图片的实现

package com.fxr.生成随机图片;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;

public class Main {

    public static Random random = new Random();
     public static int r(int min,int max){
            int num=0;
            num=random.nextInt(max-min)+min;
            return num;
        }
    public static void main(String[] args) {
        //在内存中创建一张图片
        int w = 120;
        int h = 50;
        BufferedImage img = new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
    
        //在图片上画一个矩形当背景
        Graphics g = img.getGraphics();
         g.setColor(new Color(r(50,250),r(50,250),r(50,250)));
            g.fillRect(0, 0, w, h);
             
            String str = "aqzxswedcfrvgtbhyujklp23456789";
            for(int i=0;i<4;i++){
                g.setColor(new Color(r(50,180),r(50,180),r(50,180)));
                g.setFont(new Font("黑体",Font.PLAIN,40));
                char c = str.charAt(r(0,str.length()));
                g.drawString(String.valueOf(c), 10+i*30, r(h-30,h));
            }
             
            //画随机线
            for(int i=0;i<25;i++){
                g.setColor(new Color(r(50,180),r(50,180),r(50,180)));
                g.drawLine(r(0,w), r(0,h),r(0,w), r(0,h));
            }
            //把内存中创建的图像输出到文件中
            File file =new File("e.png");
            try {
                ImageIO.write(img, "png", file);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            System.out.println("图片输出完成");
             
    
    
    }
    
    
    
    
}