用Java生成JPG

1 /**
2 有许多的动态生成的图像都是使用servlet完成的，而且代码较多，这里的这段代码是用命令生成图像文件。
3 创建一个BufferedImage对象，将你的“画”放到这个缓冲里，
4 打开一个文件，将图像流编码后输入这个文件，这样就有一个jpg文件出现了。
5 */

 1 import java.awt.Color;
 2 import java.awt.Graphics;
 3 import java.awt.image.BufferedImage;
 4 import java.io.BufferedOutputStream;
 5 import java.io.FileNotFoundException;
 6 import java.io.FileOutputStream;
 7 import java.io.IOException;
 8 import java.util.Vector;
 9 import com.sun.image.codec.jpeg.*;
10
11 public class treGraphics {
12     BufferedImage image;
13
14     // 创建jpg文件到指定路径下
15     public void createJpg(String path) {
16         try{
17             FileOutputStream fos = new FileOutputStream(path);
18             BufferedOutputStream bos = new BufferedOutputStream(fos);
19             JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(bos);
20             encoder.encode(image);
21             bos.close();
22
23         }catch(FileNotFoundException fnfe){
24             System.out.println(fnfe);
25         }catch(IOException ioe){
26             System.out.println(ioe);
27         }
28     }
29     public static void main(String[] args){
30         int width=400,height=200;
31         int xLength = 300,yLength = 150;
32         int count =5;
33         Vector data = new Vector();
34         data.addElement(new Integer(100));
35         data.addElement(new Integer(120));
36         data.addElement(new Integer(150));
37         data.addElement(new Integer(40));
38         data.addElement(new Integer(5));
39         treGraphics tg = new treGraphics();
40         tg.image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
41         Graphics g = tg.image.getGraphics();
42         //画坐标
43         g.setColor(Color.white);
44         g.fillRect(0, 0, width, height);
45         g.setColor(Color.blue);
46         g.drawLine(10,height-10,10,height-10-yLength);
47         g.drawLine(10, height-10, 10+xLength, height-10);
48         //连线
49         int yTo;
50         int yFrom = ((Integer)(data.elementAt(0))).intValue();
51         for(int i=1;i<count;i++){
52             yTo = ((Integer)(data.elementAt(i))).intValue();
53             g.drawLine(10+i*xLength/count, height-10, 10+i*xLength/count, height-15);
54             g.drawLine(10+(i-1)*xLength/count, yFrom, 10+i*xLength/count, yTo);
55             yFrom = yTo;
56         }
57         tg.createJpg("D:aaa.jpg");
58     }
59 }