[Java]ファイルの拡張子が JPG であるかを問い合わせるスニペット

JpegExtCheck.java

package net.tomoyamkung;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class ImageUtil {

    /**
	 * ファイルの拡張子が JPG であるかを問い合わせる。
	 * 
	 * @param fileName 画像ファイルのパス
	 * @return パスが ".jpg", ".jpeg", ".JPG", ".JPEG" で終わっていれば true 
	 * @throws IOException
	 */
	public static Boolean isJpg(String fileName) throws IOException {
		List<String> exts = new ArrayList<String>();
		exts.add(".jpeg");
		exts.add(".jpg");
		
		for (String ext : exts) {
			if (fileName.endsWith(ext)) {
				return true;
			}
			if (fileName.endsWith(ext.toUpperCase())) {
				return true;
			}
		}
		return false;
	}

}

JpegExtCheckTest.java

package net.tomoyamkung;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;

import org.junit.Test;

public class ImageUtilTest {

    @Test
	public void isJpg_jpg() throws Exception {
		// Setup
		String fileName = "a.jpg";
		// Exercise
		// Verify
		assertThat(ImageUtil.isJpg(fileName), is(true)); 
	}
	
	@Test
	public void isJpg_JPG() throws Exception {
		// Setup
		String fileName = "a.JPG";
		// Exercise
		// Verify
		assertThat(ImageUtil.isJpg(fileName), is(true)); 
	}
	
	@Test
	public void isJpg_jpeg() throws Exception {
		// Setup
		String fileName = "a.jpeg";
		// Exercise
		// Verify
		assertThat(ImageUtil.isJpg(fileName), is(true)); 
	}
	
	@Test
	public void isJpg_JPEG() throws Exception {
		// Setup
		String fileName = "a.JPEG";
		// Exercise
		// Verify
		assertThat(ImageUtil.isJpg(fileName), is(true)); 
	}
		
	@Test
	public void isJpg_gif() throws Exception {
		// Setup
		String fileName = "a.gif";
		// Exercise
		// Verify
		assertThat(ImageUtil.isJpg(fileName), is(false)); 
	}
	
	@Test
	public void isJpg_GIF() throws Exception {
		// Setup
		String fileName = "a.GIF";
		// Exercise
		// Verify
		assertThat(ImageUtil.isJpg(fileName), is(false)); 
	}
			
	@Test
	public void isJpg_png() throws Exception {
		// Setup
		String fileName = "a.png";
		// Exercise
		// Verify
		assertThat(ImageUtil.isJpg(fileName), is(false)); 
	}
				
	@Test
	public void isJpg_PNG() throws Exception {
		// Setup
		String fileName = "a.PNG";
		// Exercise
		// Verify
		assertThat(ImageUtil.isJpg(fileName), is(false)); 
	}

}