/*
* Copyright 2013 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.zxing.client.j2se;
import javax.imageio.ImageIO;
import javax.xml.bind.DatatypeConverter;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.net.URI;
import java.net.URLDecoder;
/**
* Encapsulates reading URIs as images.
*
* @author Sean Owen
*/
public final class ImageReader {
private static final String BASE64TOKEN = "base64,";
private ImageReader() {
}
public static BufferedImage readImage(URI uri) throws IOException {
if ("data".equals(uri.getScheme())) {
return readDataURIImage(uri);
}
BufferedImage result;
try {
result = ImageIO.read(uri.toURL());
} catch (IllegalArgumentException iae) {
throw new IOException("Resource not found: " + uri, iae);
}
if (result == null) {
throw new IOException("Could not load " + uri);
}
return result;
}
public static BufferedImage readDataURIImage(URI uri) throws IOException {
String uriString = uri.toString();
if (!uriString.startsWith("data:image/")) {
throw new IOException("Unsupported data URI MIME type");
}
int base64Start = uriString.indexOf(BASE64TOKEN);
if (base64Start < 0) {
throw new IOException("Unsupported data URI encoding");
}
String base64DataEncoded = uriString.substring(base64Start
+ BASE64TOKEN.length());
String base64Data = URLDecoder.decode(base64DataEncoded, "UTF-8");
byte[] imageBytes = DatatypeConverter.parseBase64Binary(base64Data);
return ImageIO.read(new ByteArrayInputStream(imageBytes));
}
}