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<TITLE>Listing the Image Formats That Can Be Read and Written
(Java Developers Almanac Example)
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<META CONTENT="Patrick Chan" NAME="AUTHOR">
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<A HREF="../index.html">List of Packages</A>
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<B><A HREF="../javax.imageio/pkg.html">javax.imageio</A></B><font color="#666666" SIZE="-2">
[6 examples]
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<h3>
e700.
Listing the Image Formats That Can Be Read and Written</h3>
By default, the <code>javax.imageio</code> package can read GIF, PNG, and JPEG
images and can write PNG and JPEG images. The complete list of
available readable and writeable formats can be retrieved by calling
<code>ImageIO.getReaderFormatNames()</code> and
<code>ImageIO.getWriterFormatNames()</code>.
<P> Note: These methods may return the format name in both lowercase
and uppercase. This example implements a <code>unique()</code> method that
removes duplicates, regardless of case.
<pre>
// Get list of unique supported read formats
String[] formatNames = ImageIO.getReaderFormatNames();
formatNames = unique(formatNames);
// e.g. png jpeg gif jpg
// Get list of unique supported write formats
formatNames = ImageIO.getWriterFormatNames();
formatNames = unique(formatNames);
// e.g. png jpeg jpg
// Get list of unique MIME types that can be read
formatNames = ImageIO.getReaderMIMETypes();
formatNames = unique(formatNames);
// e.g image/jpeg image/png image/x-png image/gif
// Get list of unique MIME types that can be written
formatNames = ImageIO.getWriterMIMETypes();
formatNames = unique(formatNames);
// e.g. image/jpeg image/png image/x-png
// Converts all strings in 'strings' to lowercase
// and returns an array containing the unique values.
// All returned values are lowercase.
public static String[] unique(String[] strings) {
Set set = new HashSet();
for (int i=0; i<strings.length; i++) {
String name = strings[i].toLowerCase();
set.add(name);
}
return (String[])set.toArray(new String[0]);
}
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Related Examples
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e698. <a class="eglink" href="BasicImageRead.html?l=rel">
Reading an Image from a File, InputStream, or URL
</a>
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e699. <a class="eglink" href="Graphic2File.html?l=rel">
Saving a Generated Graphic to a PNG or JPEG File
</a>
<br>
e701. <a class="eglink" href="DetermineFormat.html?l=rel">
Determining If an Image Format Can Be Read or Written
</a>
<br>
e702. <a class="eglink" href="DiscType.html?l=rel">
Determining the Format of an Image in a File
</a>
<br>
e703. <a class="eglink" href="JpegWrite.html?l=rel">
Compressing a JPEG File
</a>
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