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1
14 package org.wings.externalizer;
15
16 import Acme.JPM.Encoders.GifEncoder;
17 import com.keypoint.PngEncoder;
18 import org.apache.commons.logging.Log;
19 import org.apache.commons.logging.LogFactory;
20 import org.wings.io.Device;
21 import org.wings.io.DeviceOutputStream;
22
23 import java.awt.*;
24 import java.util.Collection  ;
25
26
31 public class ImageExternalizer implements Externalizer {
32
33 private final transient static Log log = LogFactory.getLog(ImageExternalizer.class);
34
35 public static final String FORMAT_PNG = "png";
36 public static final String FORMAT_GIF = "gif";
37
38 private static final String [] SUPPORTED_FORMATS = {FORMAT_PNG, FORMAT_GIF};
39 private static final Class [] SUPPORTED_CLASSES = {Image.class};
40
41 public static final ImageExternalizer SHARED_GIF_INSTANCE = new ImageExternalizer(FORMAT_GIF);
42 public static final ImageExternalizer SHARED_PNG_INSTANCE = new ImageExternalizer(FORMAT_PNG);
43
44 protected String format;
45
46 protected final String [] supportedMimeTypes = new String [1];
47
48 public ImageExternalizer() {
49 this(FORMAT_PNG);
50 }
51
52 public ImageExternalizer(String format) {
53 this.format = format;
54 checkFormat();
55
56 supportedMimeTypes[0] = getMimeType(null);
57 }
58
59 protected void checkFormat() {
60 for (int i = 0; i < SUPPORTED_FORMATS.length; i++) {
61 if (SUPPORTED_FORMATS[i].equals(format))
62 return;
63 }
64 throw new IllegalArgumentException ("Unsupported Format " + format);
65 }
66
67 public String getExtension(Object obj) {
68 return format;
69 }
70
71 public String getMimeType(Object obj) {
72 return "image/" + format;
73 }
74
75 public int getLength(Object obj) {
76 return -1;
77 }
78
79 public boolean isFinal(Object obj) {
80 return false;
81 }
82
83 public Class [] getSupportedClasses() {
84 return SUPPORTED_CLASSES;
85 }
86
87 public String [] getSupportedMimeTypes() {
88 return supportedMimeTypes;
89 }
90
91 public void write(Object obj, Device out)
92 throws java.io.IOException {
93 Image img = (Image) obj;
94 if (FORMAT_PNG.equals(format))
95 writePNG(img, out);
96 else
97 writeGIF(img, out);
98 }
99
100
103 public void writeGIF(Image img, Device out)
104 throws java.io.IOException {
105 GifEncoder encoder = new GifEncoder(img, new DeviceOutputStream(out),
106 true);
107 encoder.encode();
108 }
109
110
113 public void writePNG(Image img, Device out)
114 throws java.io.IOException {
115 PngEncoder png = new PngEncoder(img, PngEncoder.ENCODE_ALPHA,
116 PngEncoder.FILTER_NONE, 6);
117 byte[] pngbytes = png.pngEncode();
118 if (pngbytes == null) {
119 log.fatal("null image");
120 } else {
121 out.write(pngbytes);
122 }
123 out.flush();
124 }
125
126 public Collection getHeaders(Object obj) {
127 return null;
128 }
129 }
130
131
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