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58 package org.krysalis.barcode.output.bitmap;
59
60 import java.util.Iterator  ;
61 import java.util.Set ;
62
63
68 public class BitmapEncoderRegistry {
69
70 private static Set encoders = new java.util.TreeSet ();
71
72 static {
73 register("org.krysalis.barcode.output.bitmap.SunJPEGBitmapEncoder", 0, false);
74 register("org.krysalis.barcode.output.bitmap.ImageIOBitmapEncoder", 50, false);
75 }
76
77
80 protected BitmapEncoderRegistry() {
81 throw new UnsupportedOperationException ();
82 }
83
84 private static class Entry implements Comparable {
85 private BitmapEncoder encoder;
86 private int priority;
87
88 public Entry(BitmapEncoder encoder, int priority) {
89 this.encoder = encoder;
90 this.priority = priority;
91 }
92
93
96 public int compareTo(Object o) {
97 Entry e = (Entry)o;
98 return e.priority - this.priority; }
100 }
101
102 private static void register(String classname, int priority, boolean complain) {
103 boolean failed = false;
104 try {
105 Class clazz = Class.forName(classname);
106 BitmapEncoder encoder = (BitmapEncoder)clazz.newInstance();
107 encoders.add(new Entry(encoder, priority));
108 } catch (Exception e) {
109 failed = true;
110 } catch (LinkageError le) {
111 failed = true; }
113 if (failed) {
114 if (complain) {
115 throw new IllegalArgumentException (
116 "The implementation being registered is unavailable or "
117 + "cannot be instantiated: " + classname);
118 } else {
119 return;
120 }
121 }
122 }
123
124
131 public static void register(String classname, int priority) {
132 register(classname, priority, true);
133 }
134
135
142 public static boolean supports(BitmapEncoder encoder, String mime) {
143 String [] mimes = encoder.getSupportedMIMETypes();
144 for (int i = 0; i < mimes.length; i++) {
145 if (mimes[i].equals(mime)) {
146 return true;
147 }
148 }
149 return false;
150 }
151
152
158 public static boolean supports(String mime) {
159 Iterator i = encoders.iterator();
160 while (i.hasNext()) {
161 Entry entry = (Entry)i.next();
162 BitmapEncoder encoder = entry.encoder;
163 if (supports(encoder, mime)) {
164 return true;
165 }
166 }
167 return false;
168 }
169
170
176 public static BitmapEncoder getInstance(String mime) {
177 Iterator i = encoders.iterator();
178 while (i.hasNext()) {
179 Entry entry = (Entry)i.next();
180 BitmapEncoder encoder = entry.encoder;
181 if (supports(encoder, mime)) {
182 return encoder;
183 }
184 }
185 throw new UnsupportedOperationException (
186 "No BitmapEncoder available for " + mime);
187 }
188
189
194 public static Set getSupportedMIMETypes() {
195 Set mimes = new java.util.HashSet ();
196 Iterator i = encoders.iterator();
197 while (i.hasNext()) {
198 Entry entry = (Entry)i.next();
199 BitmapEncoder encoder = entry.encoder;
200 String [] s = encoder.getSupportedMIMETypes();
201 for (int j = 0; j < s.length; j++) {
202 mimes.add(s[j]);
203 }
204 }
205 return mimes;
206 }
207
208 }
209 |
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