java生成图片验证码示例代码

import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStream;import java.util.Random;import javax.imageio.ImageIO;/* * 步骤： * 1.画框 * 2.画背景 * 3.画字符 * 4.画干扰线 */public final class ImageUtil {     // 验证码字符集  private static final char[] chars = {     '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',     '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'};  // 字符数量  private static final int SIZE = 4;  // 干扰线数量  private static final int LINES = 5;  // 宽度  private static final int WIDTH = 80;  // 高度  private static final int HEIGHT = 40;  // 字体大小  private static final int FONT_SIZE = 30;   /**   * 生成随机验证码及图片   * Object[0]验证码字符串String   * Object[1]验证码图片  BufferedImage   */  public static Object[] createImage() {    StringBuffer sb = new StringBuffer();    // 1.创建空白图片    BufferedImage image = new BufferedImage(      WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);    // 2.获取图片画笔    Graphics graphic = image.getGraphics();    // 3.设置画笔颜色    graphic.setColor(Color.LIGHT_GRAY);    // 4.绘制矩形背景    graphic.fillRect(0, 0, WIDTH, HEIGHT);    // 5.画随机字符    Random ran = new Random();    for (int i = 0; i <SIZE; i++) {      // 取随机字符索引      int n = ran.nextInt(chars.length);      // 设置随机颜色      graphic.setColor(getRandomColor());      // 设置字体大小      graphic.setFont(new Font(        null, Font.BOLD + Font.ITALIC, FONT_SIZE));      // 画字符      graphic.drawString(        chars[n] + "", i * WIDTH / SIZE, HEIGHT / 2);      // 记录字符      sb.append(chars[n]);    }    // 6.画干扰线    for (int i = 0; i < LINES; i++) {      // 设置随机颜色      graphic.setColor(getRandomColor());      // 随机画线      graphic.drawLine(ran.nextInt(WIDTH), ran.nextInt(HEIGHT),          ran.nextInt(WIDTH), ran.nextInt(HEIGHT));    }    // 7.返回验证码和图片    return new Object[]{sb.toString(), image};  }   /**   * 随机取色   */  public static Color getRandomColor() {    Random ran = new Random();    Color color = new Color(ran.nextInt(256),         ran.nextInt(256), ran.nextInt(256));    return color;  }     public static void main(String[] args) throws IOException {    Object[] objs = createImage();    BufferedImage image = (BufferedImage) objs[1];    //图片格式可以自定义，java对png图片显示更清楚，输出路径可自定义    OutputStream os = new FileOutputStream("d:/x.png");    //注意图片格式与创建格式匹配    ImageIO.write(image, "png", os);    os.close();  } }