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20 package org.apache.mina.example.imagine.step1.server;
21
22 import org.apache.mina.common.IoHandlerAdapter;
23 import org.apache.mina.common.IoSession;
24 import org.apache.mina.example.imagine.step1.ImageRequest;
25 import org.apache.mina.example.imagine.step1.ImageResponse;
26 import org.slf4j.Logger;
27 import org.slf4j.LoggerFactory;
28
29 import java.awt.Color;
30 import java.awt.Font;
31 import java.awt.Graphics;
32 import java.awt.image.BufferedImage;
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40
41 public class ImageServerIoHandler extends IoHandlerAdapter {
42
43 private final static String characters = "mina rocks abcdefghijklmnopqrstuvwxyz0123456789";
44
45 public static final String INDEX_KEY = ImageServerIoHandler.class.getName() + ".INDEX";
46
47 private Logger logger = LoggerFactory.getLogger(this.getClass());
48
49 public void sessionOpened(IoSession session) throws Exception {
50 session.setAttribute(INDEX_KEY, 0);
51 }
52
53 public void exceptionCaught(IoSession session, Throwable cause) throws Exception {
54 logger.warn(cause.getMessage(), cause);
55 }
56
57 public void messageReceived(IoSession session, Object message) throws Exception {
58 ImageRequest request = (ImageRequest) message;
59 String text1 = generateString(session, request.getNumberOfCharacters());
60 String text2 = generateString(session, request.getNumberOfCharacters());
61 BufferedImage image1 = createImage(request, text1);
62 BufferedImage image2 = createImage(request, text2);
63 ImageResponse response = new ImageResponse(image1, image2);
64 session.write(response);
65 }
66
67 private BufferedImage createImage(ImageRequest request, String text) {
68 BufferedImage image = new BufferedImage(request.getWidth(), request.getHeight(), BufferedImage.TYPE_BYTE_INDEXED);
69 Graphics graphics = image.createGraphics();
70 graphics.setColor(Color.YELLOW);
71 graphics.fillRect(0, 0, image.getWidth(), image.getHeight());
72 Font serif = new Font("serif", Font.PLAIN, 30);
73 graphics.setFont(serif);
74 graphics.setColor(Color.BLUE);
75 graphics.drawString(text, 10, 50);
76 return image;
77 }
78
79 private String generateString(IoSession session, int length) {
80 Integer index = (Integer) session.getAttribute(INDEX_KEY);
81 StringBuffer buffer = new StringBuffer(length);
82 while (buffer.length() < length) {
83 buffer.append(characters.charAt(index));
84 index++;
85 if (index >= characters.length()) {
86 index = 0;
87 }
88 }
89 session.setAttribute(INDEX_KEY, index);
90 return buffer.toString();
91 }
92
93 }