java图片验证码

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BuffererImage;
import java.io.IOException;
import java.util.Random;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class RandomImage extends HttpServlet{
//不包括0，O,1,I易混乱字符
public static final char[] CHARS = {‘2’,’3’,’4’,’5’,’6’,’7’,’8’,’9’,’A’,’B’,’C’,’D’,’E’,’F’,’G’,’H’,’I’,’G’,’K’,’L’,’M’,’N’,’P’,’Q’,’R’,’S’,’T’,’U’,’V’,’W’,’X’,’Y’,’Z’};
public static Random random = new Random();
public static String getRandomString(){
StringBuffer buffer = new StringBuffer();
//产生6位随机数
for(int i = 0;i<6,i++){
//每次取一个随机字符 buffer.append(CHARS[random.nextInt(CHARS.length)]);
}
return buffer.toString();
}
//获取随机颜色
public static Color getImageColor(){
return new Color(random.nextInt(255),random.nextInt(255),random.nextInt(255));
}
//返回某个颜色的反色
public static Color getReserverColor(Color c){
return new Color(255-c.getRed()，255-c.getGreen()，255-c.getBlue())
}

}