/*
* Copyright 2002-2013 Drew Noakes
*
* 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.
*
* More information about this project is available at:
*
* http://drewnoakes.com/code/exif/
* http://code.google.com/p/metadata-extractor/
*/
package com.drew.metadata;
import com.drew.imaging.ImageMetadataReader;
import com.drew.imaging.ImageProcessingException;
import com.drew.imaging.jpeg.JpegMetadataReader;
import com.drew.imaging.jpeg.JpegProcessingException;
import com.drew.imaging.jpeg.JpegSegmentMetadataReader;
import com.drew.metadata.exif.ExifReader;
import com.drew.metadata.iptc.IptcReader;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;
/**
* Showcases the most popular ways of using the metadata-extractor library.
* <p/>
* For more information, see the project wiki: https://code.google.com/p/metadata-extractor/wiki/GettingStarted
*
* @author Drew Noakes http://drewnoakes.com
*/
public class SampleUsage
{
/**
* Executes the sample usage program.
*
* @param args command line parameters
*/
public static void main(String[] args)
{
File file = new File("Tests/Data/withIptcExifGps.jpg");
// There are multiple ways to get a Metadata object for a file
//
// SCENARIO 1: UNKNOWN FILE TYPE
//
// This is the most generic approach. It will transparently determine the file type and invoke the appropriate
// readers. In most cases, this is the most appropriate usage. This will handle JPEG, TIFF, GIF, BMP and RAW
// (CRW/CR2/NEF/RW2/ORF) files and extract whatever metadata is available and understood.
//
try {
Metadata metadata = ImageMetadataReader.readMetadata(file);
print(metadata);
} catch (ImageProcessingException e) {
// handle exception
} catch (IOException e) {
// handle exception
}
//
// SCENARIO 2: SPECIFIC FILE TYPE
//
// If you know the file to be a JPEG, you may invoke the JpegMetadataReader, rather than the generic reader
// used in approach 1. Similarly, if you knew the file to be a TIFF/RAW image you might use TiffMetadataReader,
// PngMetadataReader for PNG files, BmpMetadataReader for BMP files, or GifMetadataReader for GIF files.
//
// Using the specific reader offers a very, very slight performance improvement.
//
try {
Metadata metadata = JpegMetadataReader.readMetadata(file);
print(metadata);
} catch (JpegProcessingException e) {
// handle exception
} catch (IOException e) {
// handle exception
}
//
// APPROACH 3: SPECIFIC METADATA TYPE
//
// If you only wish to read a subset of the supported metadata types, you can do this by
// passing the set of readers to use.
//
// This currently only applies to JPEG file processing.
//
try {
// We are only interested in handling
Iterable<JpegSegmentMetadataReader> readers = Arrays.asList(new ExifReader(), new IptcReader());
Metadata metadata = JpegMetadataReader.readMetadata(file, readers);
print(metadata);
} catch (JpegProcessingException e) {
// handle exception
} catch (IOException e) {
// handle exception
}
}
private static void print(Metadata metadata)
{
System.out.println("-------------------------------------");
// Iterate over the data and print to System.out
//
// A Metadata object contains multiple Directory objects
//
for (Directory directory : metadata.getDirectories()) {
//
// Each Directory stores values in Tag objects
//
for (Tag tag : directory.getTags()) {
System.out.println(tag);
}
//
// Each Directory may also contain error messages
//
if (directory.hasErrors()) {
for (String error : directory.getErrors()) {
System.err.println("ERROR: " + error);
}
}
}
}
}