Android随机获取验证码函数示例

 package cn.hk.image; 
import java.awt.BasicStroke; 
import java.awt.Color; 
import java.awt.Font; 
import java.awt.Graphics2D; 
import java.awt.image.BufferedImage; 
import java.io.IOException; 
import java.io.OutputStream; 
import java.util.Random; 
import javax.imageio.ImageIO; 
public class VerifyCode { 
  private int w = 70; 
  private int h = 35; 
  private Random r = new Random(); 
  // {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"} 
  private String[] fontNames = {"宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312"}; 
  // 可选字符 
  private String codes = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ"; 
  // 背景色 
  private Color bgColor = new Color(255, 255, 255); 
  // 验证码上的文本 
  private String text ; 
  // 生成随机的颜色 
  private Color randomColor () { 
    int red = r.nextInt(150); 
    int green = r.nextInt(150); 
    int blue = r.nextInt(150); 
    return new Color(red, green, blue); 
  } 
  // 生成随机的字体 
  private Font randomFont () { 
    int index = r.nextInt(fontNames.length); 
    String fontName = fontNames[index];//生成随机的字体名称 
    int style = r.nextInt(4);//生成随机的样式, 0(无样式), 1(粗体), 2(斜体), 3(粗体+斜体) 
    int size = r.nextInt(5) + 24; //生成随机字号, 24 ~ 28 
    return new Font(fontName, style, size); 
  } 
  // 画干扰线 
  private void drawLine (BufferedImage image) { 
    int num = 3;//一共画3条 
    Graphics2D g2 = (Graphics2D)image.getGraphics(); 
    for(int i = 0; i