标签:ado def ase date 技术 ajax nal wstring users
htmlimport org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import sun.misc.BASE64Encoder;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
public class RandomValidateCodeUtil {
public static final String RANDOMCODEKEY = "randomcode_key";//放到session中的key
private Random random = new Random();
private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生的字符串
private int width = 85;//图片宽
private int height = 36;//图片高
private int lineSize = 40;//干扰线数量
private int stringNum = 4;//随机产生字符数量
private static final Logger logger = LoggerFactory.getLogger(RandomValidateCodeUtil.class);
/**
* 生成随机图片
*/
public Map<String,String> getRandcode() {
// BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
Graphics g = image.getGraphics();// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
g.fillRect(0, 0, width, height);//图片大小
g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));//字体大小
g.setColor(getRandColor(110, 133));//字体颜色
// 绘制干扰线
for (int i = 0; i <= lineSize; i++) {
drowLine(g);
}
// 绘制随机字符
String randomString = "";
for (int i = 1; i <= stringNum; i++) {
randomString = drowString(g, randomString, i);
}
logger.info(randomString);
//将生成的随机字符串保存到session中
//session.removeAttribute(RANDOMCODEKEY);
//session.setAttribute(RANDOMCODEKEY, randomString);
g.dispose();
String base64 = null;
try {
// 将内存中的图片通过流动形式输出到客户端
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write(image, "JPEG", baos);//图片格式
byte[] bytes = baos.toByteArray();
base64 = new BASE64Encoder().encodeBuffer(bytes).trim();
} catch (Exception e) {
logger.error("将内存中的图片通过流动形式输出到客户端失败>>>> ", e);
}
Map<String,String> map = new HashMap<String,String>();
map.put("num", randomString);
map.put("pic", base64);
return map;
}
/*
* 获得字体
*/
private Font getFont(){
return new Font("Fixedsys",Font.CENTER_BASELINE,18);
}
/*
* 获得颜色
*/
private Color getRandColor(int fc,int bc){
if(fc > 255)
fc = 255;
if(bc > 255)
bc = 255;
int r = fc + random.nextInt(bc-fc-16);
int g = fc + random.nextInt(bc-fc-14);
int b = fc + random.nextInt(bc-fc-18);
return new Color(r,g,b);
}
/*
* 绘制字符串
*/
private String drowString(Graphics g,String randomString,int i){
g.setFont(getFont());
g.setColor(new Color(random.nextInt(101),random.nextInt(111),random.nextInt(121)));
String rand = String.valueOf(getRandomString(random.nextInt(randString.length())));
randomString +=rand;
g.translate(random.nextInt(3), random.nextInt(3));
g.drawString(rand, 13*i, 16);
return randomString;
}
/*
* 绘制干扰线
*/
private void drowLine(Graphics g){
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(13);
int yl = random.nextInt(15);
g.drawLine(x, y, x+xl, y+yl);
}
/*
* 获取随机的字符
*/
public String getRandomString(int num){
return String.valueOf(randString.charAt(num));
}
}
标签:ado def ase date 技术 ajax nal wstring users
原文地址:http://blog.51cto.com/13579083/2328342