voteimage.java

J2EE独立开发制作

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.geom.*;
import java.awt.image.*;
public class VoteImage extends HttpServlet 
{
private String strFile = null;
private Color color[]={Color.red,Color.black,Color.orange,Color.green};
private int baseAng = 30;
public void doGet(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException 
{
strFile = request.getRealPath("count.txt");
float[][] xy = new float[4][2];
xy = getNumAndPercent(strFile);
int[] ang = new int[4];
ang[0] = (int)(xy[0][1]*360);
ang[1] = (int)(xy[1][1]*360);
ang[2] = (int)(xy[2][1]*360);
ang[3] = 360-ang[0]-ang[1]-ang[2];
response.setHeader("Cache-Control","no-store");
response.setDateHeader("Expires",0);
response.setContentType("image/jpeg");
ServletOutputStream out=response.getOutputStream();
BufferedImage image=new BufferedImage(150,100,BufferedImage.TYPE_INT_RGB);
Graphics2D g=(Graphics2D)image.getGraphics();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
g.setColor(Color.white);
g.fillRect(0,0,150,100); 
AffineTransform at = null;
Arc2D arc = null;
int fromAng = baseAng;
at = AffineTransform.getRotateInstance((-20*java.lang.Math.PI)/180,45,37);
g.setTransform(at);
int r =6;
int dx = (int)(r*java.lang.Math.cos((baseAng+ang[0])/2.0*java.lang.Math.PI/180));
int dy = (int)(r*java.lang.Math.sin((baseAng+ang[0])/2.0*java.lang.Math.PI/180));
arc = new Arc2D.Double(10,24,80,50,fromAng,ang[0],Arc2D.PIE);
g.setColor(color[0]);
g.fill(arc);
fromAng+=ang[0];
for (int i=1;i<4;i++)
{
g.setColor(color[i]);
arc = new Arc2D.Double(10,24,80,50,fromAng,ang[i],Arc2D.PIE);
g.fill(arc);
fromAng+=ang[i];
if (fromAng>360)
{
fromAng-=360;
}
}
at = AffineTransform.getRotateInstance(0,arc.getCenterX(),arc.getCenterY());
g.setTransform(at);
for (int i=0;i<4;i++)
{
g.setColor(color[i]);
g.fillRect(100,15*i+20,10,10);
//g.drawString((char)("A"+i)+"",120,15*i+20+8);
g.drawString("A"+i,120,15*i+20+8);
}
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 float[][] getNumAndPercent(String sFileName)
{
float xx[][] = new float[4][2];
int totalNum = 0 ;
String strTemp = null;
int i = 0;
java.io.RandomAccessFile rf = null;
try 
{
rf = new java.io.RandomAccessFile (sFileName,"r");
}
 catch(Exception e)
{
System.out.println(e);
System.exit(0);
}
for (i=0;i<4;i++)
{
int m=0;
try 
{
strTemp = rf.readLine();
} 
catch (Exception e)
{
strTemp = "0";
}

if (strTemp == null) 
strTemp = "0";
//m = new Integer(strTemp).intValue();
m=Integer.parseInt(strTemp);
xx[i][0]=m;
totalNum += m;
}
if (totalNum==0)
 totalNum=1;
for ( i=0;i<4;i++){
xx[i][1] = xx[i][0]/totalNum;
}
return xx;
}
}