Wizzer's Blog

package web.common.util;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

import java.io.IOException;
import java.awt.image.BufferedImage;
import java.awt.*;
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 javax.servlet.http.HttpSession;

/**
 * @author Wizzer.cn
 * @time   2012-9-13 上午10:54:04
 *
 */
public class ImageUtil extends HttpServlet {

	private static final long serialVersionUID = 1L;
	private static final String CONTENT_TYPE = "image/jpeg;charset=GB2312";
	private static final String allcode[] = { "0", "1", "2", "3", "4", "5",
			"6", "7", "8", "9" };

	private static final Font mFont = new Font("Times New Roman", Font.BOLD, 18);// 设置字体

	public static Font IFont = new Font("宋体", Font.PLAIN, 18);// 设置字体

	public static int x = 10; // 坐标
	public static int y = 10;

	public void init() throws ServletException {
	}

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doPost(request, response);
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType(CONTENT_TYPE);
		ServletOutputStream out = response.getOutputStream();
		getImage(out, request, response);
		out.close();
	}

	private void getImage(ServletOutputStream out, HttpServletRequest request,
			HttpServletResponse response) {
		try {

			HttpSession session = request.getSession(true);

			response.setContentType("image/gif");
			response.setHeader("Pragma", "No-cache");
			response.setHeader("Cache-Control", "no-cache");
			response.setDateHeader("Expires", 0);
			int width = 60, height = 20;

			BufferedImage image = new BufferedImage(width, height,
					BufferedImage.TYPE_INT_RGB); // 设置图片大小的
			Graphics gra = image.getGraphics();
			Random random = new Random();

			gra.setColor(getRandColor(200, 250)); // 设置背景色
			gra.fillRect(0, 0, width, height);

			gra.setColor(Color.black); // 设置字体色
			gra.setFont(mFont);

			// 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到

			for (int i = 0; i < 100; i++) {
				gra.setColor(getRandColor(120, 220));
				x = random.nextInt(width);
				y = random.nextInt(height);
				int xl = random.nextInt(12);
				int yl = random.nextInt(12);
				gra.drawLine(x, y, x + xl, y + yl);
			}

			// 取随机产生的认证码(4位)
			String sRand = "";
			for (int i = 0; i < 4; i++) {
				String rand = allcode[random.nextInt(10)];
				sRand += rand;
				// 将认证码显示到图象中
				gra.setColor(new Color(20 + random.nextInt(110), 20 + random
						.nextInt(110), 20 + random.nextInt(110)));// 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
				gra.drawString(rand, 13 * i + 6, 12 + random.nextInt(5));
			}
			session.setAttribute("ValidateCode", sRand);
			JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
			encoder.encode(image);
			out.close();

		} catch (Exception e) {
			e.printStackTrace();

		}
	}

	static Color getRandColor(int fc, int bc) {// 给定范围获得随机颜色

		Random random = new Random();
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}

	public static Font getIFont() {
		return IFont;
	}

	public static void setIFont(Font IFont) {
		ImageUtil.IFont = IFont;
	}

	public static int getY() {
		return y;
	}

	public static void setY(int y) {
		ImageUtil.y = y;
	}

	public static int getX() {
		return x;
	}

	public static void setX(int x) {
		ImageUtil.x = x;
	}

}

若提示找不到包：

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

则做如下修改即可：

Eclipse 默认把这些受访问限制的API设成了ERROR。

只要把 Deprecated and restricted API中的Forbidden references(access rules) 选为Warning 就可以编译通过。