Image File Extension Regular Expression Pattern.
|
([^\s]+(\.(?i)(jpg|png|gif|bmp))$)
|
Description
( #Start of the group #1 [^\s]+ # must contains one or more anything (except white space)
( # start of the group #2
\. # follow by a dot "."
(?i) # ignore the case sensive checking for the following characters
( # start of the group #3
jpg # contains characters "jpg"
| # ..or
png # contains characters "png"
| # ..or
gif # contains characters "gif"
| # ..or
bmp # contains characters "bmp"
) # end of the group #3
) # end of the group #2
$ # end of the string
) #end of the group #1 |
Whole
combination is means, must have 1 or more strings (but not white space), follow
by dot “.” and string end in “jpg” or “png” or “gif” or “bmp” , and the file
extensive is case-insensitive.
This regular
expression pattern is widely use in for different file extensive checking. You
can just change the end combination (jpg|png|gif|bmp) to come out
different file extension checking that suit your need.
Java Regular
Expression Example
package com.mkyong.regex;
import java.util.regex.Matcher; import java.util.regex.Pattern;
public class ImageValidator{
private Pattern pattern;
private Matcher matcher;
private static final String IMAGE_PATTERN =
"([^\\s]+(\\.(?i)(jpg|png|gif|bmp))$)";
public ImageValidator(){
pattern = Pattern.compile(IMAGE_PATTERN);
}
/**
* Validate image with regular expression
* @param image image for validation
* @return true valid image, false invalid image
*/
public boolean validate(final String image){
matcher = pattern.matcher(image);
return matcher.matches();
}
}
|
Image file that match:
1. “a.jpg”, “a.gif”,”a.png”, “a.bmp”,2. “..jpg”, “..gif”,”..png”, “..bmp”,
3. “a.JPG”, “a.GIF”,”a.PNG”, “a.BMP”,
4. “a.JpG”, “a.GiF”,”a.PnG”, “a.BmP”,
5. “jpg.jpg”, “gif.gif”,”png.png”, “bmp.bmp”
Image that doesn’t match:
1. “.jpg”, “.gif”,”.png”,”.bmp” – image file name is required2. ” .jpg”, ” .gif”,” .png”,” .bmp” – White space is not allow in first character
3. “a.txt”, “a.exe”,”a.”,”a.mp3″ – Only image file extension is allow
3. “jpg”, “gif”,”png”,”bmp” – image file extension is required
Unit Test – ImageValidator
package com.mkyong.regex;
import org.testng.Assert; import org.testng.annotations.*;
/**
* Image validator Testing
* @author mkyong
*
*/
public class ImageValidatorTest {
private ImageValidator imageValidator;
@BeforeClass
public void initData(){
imageValidator = new ImageValidator();
}
@DataProvider
public Object[][] ValidImageProvider() {
return new Object[][]{
{new String[] {
"a.jpg", "a.gif","a.png", "a.bmp",
"..jpg", "..gif","..png", "..bmp",
"a.JPG", "a.GIF","a.PNG", "a.BMP",
"a.JpG", "a.GiF","a.PnG", "a.BmP",
"jpg.jpg", "gif.gif","png.png", "bmp.bmp"
}
}
};
}
@DataProvider
public Object[][] InvalidImageProvider() {
return new Object[][]{
{new String[] {
".jpg", ".gif",".png",".bmp",
" .jpg", " .gif"," .png"," .bmp",
"a.txt", "a.exe","a.","a.mp3",
"jpg", "gif","png","bmp"
}
}
};
}
@Test(dataProvider = "ValidImageProvider")
public void ValidImageTest(String[] Image) {
for(String temp : Image){
boolean valid = imageValidator.validate(temp);
System.out.println("Image is valid : " + temp + " , " + valid);
Assert.assertEquals(true, valid);
}
}
@Test(dataProvider = "InvalidImageProvider",
dependsOnMethods="ValidImageTest")
public void InValidImageTest(String[] Image) {
for(String temp : Image){
boolean valid = imageValidator.validate(temp);
System.out.println("Image is valid : " + temp + " , " + valid);
Assert.assertEquals(false, valid);
}
}
}
|
Unit Test – Result
Image is valid : a.jpg , true
Image is valid : a.gif , true
Image is valid : a.png , true
Image is valid : a.bmp , true
Image is valid : ..jpg , true
Image is valid : ..gif , true
Image is valid : ..png , true
Image is valid : ..bmp , true
Image is valid : a.JPG , true
Image is valid : a.GIF , true
Image is valid : a.PNG , true
Image is valid : a.BMP , true
Image is valid : a.JpG , true
Image is valid : a.GiF , true
Image is valid : a.PnG , true
Image is valid : a.BmP , true
Image is valid : jpg.jpg , true
Image is valid : gif.gif , true
Image is valid : png.png , true
Image is valid : bmp.bmp , true
Image is valid : .jpg , false
Image is valid : .gif , false
Image is valid : .png , false
Image is valid : .bmp , false
Image is valid : .jpg , false
Image is valid : .gif , false
Image is valid : .png , false
Image is valid : .bmp , false
Image is valid : a.txt , false
Image is valid : a.exe , false
Image is valid : a. , false
Image is valid : a.mp3 , false
Image is valid : jpg , false
Image is valid : gif , false
Image is valid : png , false
Image is valid : bmp , false
PASSED: ValidImageTest([Ljava.lang.String;@1d4c61c)
PASSED: InValidImageTest([Ljava.lang.String;@116471f)
===============================================
com.mkyong.regex.ImageValidatorTest
Tests run: 2, Failures: 0, Skips: 0
===============================================
===============================================
mkyong
Total tests run: 2, Failures: 0, Skips: 0
===============================================
|
Want to learn more about regular expression? Highly
recommend this best and classic book – “Mastering Regular Expression”
Hello! Experience the benefits of outsourcing with our reliable image object annotations services BPO . Our company, known for its approach to recruiting and retaining top talent, is ready to provide hight-quality data for your AI education process . From recruiting those specialists to support you AI systems, we have the resources to streamline your operations.
ReplyDelete