| import java.io.*; import java.util.*; import com.sun.image.codec.jpeg.*; import javax.servlet.*; import javax.servlet.http.*; import java.awt.*; import java.awt.image.*; public class JPEGServlet extends HttpServlet { private String strFile="c:\\count.txt"; private Font mFont=new Font("Courier", Font.BOLD,12);; public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { String s; int intCount; s=getCount(); intCount=new Integer(s).intValue(); intCount=intCount+1; writeCount(intCount+""); response.setContentType("image/jpeg"); ServletOutputStream out=response.getOutputStream(); BufferedImage image=new BufferedImage(110,16,BufferedImage.TYPE_INT_RGB); Graphics g=image.getGraphics(); g.setColor(Color.black); g.fillRect(0,0,110,16); g.setColor(Color.white); g.setFont(mFont); char c; for(int i=0;i＜10;i++) { c=s.charAt(i); g.drawString(c+"",i*11+1,12); g.drawLine((i+1)*11-1,0,(i+1)*11-1,16); } JPEGImageEncoder encoder=JPEGCodec.createJPEGEncoder(out); encoder.encode(image); out.close(); } public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { doGet(request,response); } public synchronized void writeCount(String content) { try { PrintWriter pw = new PrintWriter(new FileOutputStream(strFile)); pw.println(content); pw.close(); } catch(IOException e) { System.out.println("Write file error:"+e.getMessage()); } } public synchronized String getCount() { String strCount; int len; int leftLen; try { BufferedReader inf = new BufferedReader(new FileReader(strFile)); strCount=inf.readLine(); inf.close(); } catch(Exception e) { System.out.println("Get counter error:"+e.getMessage()); return reChar('0',10); } len=strCount.length(); if (len＜=0) { return reChar('0',10); } if (len＞10) { return reChar('9',10); } leftLen=10-len; return reChar('0',leftLen)+strCount; } private String reChar(char c,int num){ int i; if (num＜=0) return ""; String s=""; for(i=0;i＜num;i++) { s=s+c; } return s; } } |