Posted on 2008-09-10 16:42
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java
checkCode.java
package com.yz.checkcode;
import java.io.IOException;
import java.io.PrintWriter;
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;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
import java.awt.*;
import java.awt.image.*;
import java.util.*;
public class checkCode
extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
response.reset();
response.setContentType("image/jpeg");
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setHeader("Expires", "Tues, 01 Jan 1980 00:00:00 GMT");
//在內存中創建圖象
int width = 58, height = 18;
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
//獲取圖形上下文
Graphics g = image.getGraphics();
//生成隨機類
Random random = new Random();
//設定背景色
g.setColor(new Color(201 + random.nextInt(50), 201 + random.nextInt(50),
201 + random.nextInt(50)));
g.fillRect(0, 0, width, height);
//設定字體
g.setFont(new Font("Times new Roman", Font.PLAIN, 18));
//畫邊框
g.setColor(new Color(255,140,0));
g.drawRect(0,0,width-1,height-1);
//隨機產生155條干擾線，使圖象中的認證碼不易被其它程序探測到
g.setColor(new Color(160 + random.nextInt(41), 160 + random.nextInt(41),
160 + random.nextInt(41)));
for (int i = 0; i < 155; i++) {
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x, y, x + xl, y + yl);
}
//取隨機產生的認證碼
String src = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKMNOPQRSTUVWXYZ0123456789";
String sRand = "";
for (int i = 0; i < 4; i++) {
int position=random.nextInt(src.length());
String radomChar=src.charAt(position)+"";
sRand += radomChar;
//將認證碼顯示到圖象中
g.setColor(new Color(20 + random.nextInt(111), 20 + random.nextInt(111),
20 + random.nextInt(111)));
//調用函數出來的顏色相同，可能是因為種子太接近，所以只能直接生成
g.drawString( radomChar, 13 * i + 6, 16);
}
//圖象生效
g.dispose();
HttpSession session = request.getSession(true);
//將認證碼存入SESSION
session.setAttribute("checkCode", sRand);
//輸出圖象到頁面
ServletOutputStream out = response.getOutputStream();
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(image);
System.out.println("驗證碼：\t"+sRand);
out.println(sRand);
out.flush();
out.close();
}
}
getKey.java
package com.yz.checkcode;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class getKey extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
response.setCharacterEncoding("utf-8");
PrintWriter out = response.getWriter();
String key=request.getSession().getAttribute("checkCode").toString();
out.println(key);
out.flush();
out.close();
}
}