voteimage.java

一本书中的原代码,有用多例子,很好用

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 = 100;
    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];
        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);
        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];
        }
        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);
        }
    }
       
    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){}
        }
        return xx;
    }
}