Scenario
How-To
Here has sample code:
package test.util;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import org.apache.commons.io.FilenameUtils;
import org.springframework.stereotype.Component;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@Component
public class ImageUtils {
/**
* Magnify image
*
* @param oFile
* original file
* @param times
* magnification times
* @param mFile
* magnified image
* @throws IOException
*/
public void magnifyImage(File oFile, Integer times, File mFile) throws IOException {
try {
BufferedImage originalImage = ImageIO.read(oFile);
int width = originalImage.getWidth() * times;
int height = originalImage.getHeight() * times;
BufferedImage newImage = new BufferedImage(width, height, originalImage.getType());
Graphics g = newImage.getGraphics();
g.drawImage(originalImage, 0, 0, width, height, null);
g.dispose();
ImageIO.write(newImage, FilenameUtils.getExtension(mFile.getName()), mFile);
log.debug("magnified image successfully to {}", mFile.getAbsolutePath());
} catch (IOException e) {
throw new IOException("fail to magnify image", e);
}
}
/**
* Shrink image
*
* @param oFile
* original file
* @param times
* shrink times
* @param sFile
* shrinked image
* @throws IOException
*/
public void shrinkImage(File oFile, Integer times, File sFile) throws IOException {
try {
BufferedImage originalImage = ImageIO.read(oFile);
int width = originalImage.getWidth() / times;
int height = originalImage.getHeight() / times;
BufferedImage newImage = new BufferedImage(width, height, originalImage.getType());
Graphics g = newImage.getGraphics();
g.drawImage(originalImage, 0, 0, width, height, null);
g.dispose();
ImageIO.write(newImage, FilenameUtils.getExtension(sFile.getName()), sFile);
log.debug("shinked image successfully to {}", sFile.getAbsolutePath());
} catch (IOException e) {
throw new IOException("fail to shrink image", e);
}
}
}
Test class:
package test.util;
import static org.assertj.core.api.Assertions.assertThat;
import java.io.File;
import java.io.IOException;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
@RunWith(SpringRunner.class)
@SpringBootTest
public class ImageUtilsTest {
private File originalFile = new File("C:\\Users\\user\\Downloads\\originalFile.jpg");
private File shrinkFile = new File("C:\\Users\\user\\Downloads\\shrinkFile.jpg");
private File magnificationFile = new File("C:\\Users\\user\\Downloads\\manificationFile.jpg");
@Autowired
private ImageUtils imageUtils;
@Test
public void testShrinkImage() throws IOException {
imageUtils.shrinkImage(originalFile, 10, shrinkFile);
assertThat(shrinkFile.exists()).isTrue();
}
@Test
public void testMagnifyImage() throws IOException {
imageUtils.magnifyImage(shrinkFile, 2, magnificationFile);
assertThat(magnificationFile.exists()).isTrue();
}
}
