ImageKit Java SDK

Java SDK for ImageKit.io that implements the new APIs and interface for performing different file operations.

ImageKit is a complete image optimization and transformation solution that comes with and image CDN and media storage. It can be integrated with your existing infrastructure - storage like AWS s3, web servers, your CDN, and custom domain names, allowing you to deliver optimize images in minutes with minimal code changes.

Table of contents -

• Installation
• Initialization
• Usage
• URL generation
• File upload
• File management
• Utility functions
• Support
• Links

Installation

Requirements

• Java 1.8 or later

Gradle users

Step 1. Add the JitPack repository to your build file

allprojects {
	repositories {
		...
		maven { url 'https://jitpack.io' }
	}
}

Step 2. Add the dependency on project's build.gradle:

dependencies {
        implementation 'com.github.imagekit-developer:imagekit-java:1.0.3'
}

Maven users

Step 1. Add the JitPack repository to your build file

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

Step 2. Add the dependency in POM file:

<dependency>
    <groupId>com.github.imagekit-developer</groupId>
    <artifactId>imagekit-java</artifactId>
    <version>1.0.3</version>
</dependency>

Initialization

Step 1. Create a config.properties file inside src/main/resources of your project. And put essential values of keys [UrlEndpoint, PrivateKey, PublicKey], no need to use quote(' or ") in values.

# Put essential values of keys [UrlEndpoint, PrivateKey, PublicKey]
UrlEndpoint=<-YOUR-ENDPOINT-URL-HERE->
PrivateKey=<-YOUR-PRIVATE-KEY-HERE->
PublicKey=<-YOUR-PUBLIC-KEY-HERE->

Step 2. Then you need to initialize ImageKit with that configuration.

import io.imagekit.sdk.ImageKit;
import io.imagekit.sdk.config.Configuration;
import io.imagekit.sdk.utils.Utils;
class App {
   public static void main(String[] args){
       ImageKit imageKit=ImageKit.getInstance();
       Configuration config=Utils.getSystemConfig(App.class);
       imageKit.setConfig(config);
   }
}

Usage

You can use this Java SDK for 3 different kinds of methods - URL generation, file upload, and file management. The usage of the SDK has been explained below.

URL generation

1. Using image path and URL-endpoint

This method allows you to create a URL using the path where the image exists and the URL-endpoint you want to use to access the image. You can refer to the documentation here to read more about URL endpoints in ImageKit and the section about image origins to understand about paths with different kinds of origins.

Map<String, String> queryParam=new HashMap<>();
queryParam.put("v","123");

List<Map<String, String>> transformation=new ArrayList<Map<String, String>>();
Map<String, String> scale=new HashMap<>();
scale.put("height","600");
scale.put("width","400");
transformation.add(scale);
    
Map<String, Object> options=new HashMap();
options.put("urlEndpoint","https://ik.imagekit.io/your_imagekit_id/");
options.put("path","/default-image.jpg");
options.put("transformation", transformation);

String url = ImageKit.getInstance().getUrl(options);

The result in a URL like

https://ik.imagekit.io/your_imagekit_id/tr:w-400,h-600/default-image.jpg?v=123&ik-sdk-version=java-1.0.3

2. Using full image URL This method allows you to add transformation parameters to an existing complete URL that is already mapped to ImageKit using the src parameter. This method should be used if you have the complete image URL mapped to ImageKit stored in your database.

List<Map<String, String>> transformation=new ArrayList<Map<String, String>>();
Map<String, String> scale=new HashMap<>();
scale.put("height","600");
scale.put("width","400");
transformation.add(scale);

Map<String, Object> options=new HashMap();
options.put("src","https://ik.imagekit.io/your_imagekit_id/default-image.jpg");
options.put("transformation", transformation);

String url = ImageKit.getInstance().getUrl(options);

The results in a URL like

https://ik.imagekit.io/your_imagekit_id/default-image.jpg?tr=w-400,h-600&ik-sdk-version=java-1.0.3

The .getUrl() method accepts the following parameters

Option	Description
urlEndpoint	Optional. (Type: String) The base URL to be appended before the path of the image. If not specified, the URL Endpoint specified at the time of SDK initialization is used. For example, https://ik.imagekit.io/your_imagekit_id/
path	Conditional. (Type: String) This is the path at which the image exists. For example, /path/to/image.jpg. Either the path or src parameter needs to be specified for URL generation.
src	Conditional. (Type: String) This is the complete URL of an image already mapped to ImageKit. For example, https://ik.imagekit.io/your_imagekit_id/endpoint/path/to/image.jpg. Either the path or src parameter needs to be specified for URL generation.
transformation	Optional. (Type: List<Map<String,String>>) An array of objects specifying the transformation to be applied in the URL. The transformation name and the value should be specified as a key-value pair in the object. Different steps of a chained transformation can be specified as different objects of the array. The complete list of supported transformations in the SDK and some examples of using them are given later. If you use a transformation name that is not specified in the SDK, it gets applied as it is in the URL.
transformationPosition	Optional. (Type: String) Default value is path that places the transformation string as a path parameter in the URL. It can also be specified as query which adds the transformation string as the query parameter tr in the URL. If you use the src parameter to create the URL, then the transformation string is always added as a query parameter.
queryParameters	Optional. (Type: Map<String, String>) These are the other query parameters that you want to add to the final URL. These can be any query parameters and not necessarily related to ImageKit. Especially useful if you want to add some versioning parameter to your URLs.
signed	Optional. (Type: Boolean) Default is false. If set to true, the SDK generates a signed image URL adding the image signature to the image URL. This can only be used if you are creating the URL with the url_endpoint and path parameters, and not with the src parameter.
expireSeconds	Optional. (Type: Integer) Meant to be used along with the signed parameter to specify the time in seconds from now when the URL should expire. If specified, the URL contains the expiry timestamp in the URL, and the image signature is modified accordingly.

Examples of generating URLs

1. Chained Transformations as a query parameter

List<Map<String, String>> transformation=new ArrayList<Map<String, String>>();
Map<String, String> scale=new HashMap<>();
scale.put("height","300");
scale.put("width","400");
transformation.add(scale);
Map<String, String> rotate=new HashMap<>();
rotate.put("rotation","90");
transformation.add(rotate);

Map<String, Object> options=new HashMap();
options.put("path","/default-image.jpg");
options.put("transformationPosition","query");
options.put("transformation", transformation);

String url = ImageKit.getInstance().getUrl(options);

Sample Result URL -

https://ik.imagekit.io/your_imagekit_id/default-image.jpg?tr=h-300&w-400:rt-90&ik-sdk-version=java-1.0.3

2. Sharpening and contrast transforms and a progressive JPG image

There are some transforms like Sharpening that can be added to the URL with or without any other value. To use such transforms without specifying a value, specify the value as "-" in the transformation object. Otherwise, specify the value that you want to be added to this transformation.

List<Map<String, String>> transformation=new ArrayList<Map<String, String>>();
Map<String, String> scale=new HashMap<>();
scale.put("format","jpg");
scale.put("progressive","true");
scale.put("effect_sharpen","-");
scale.put("effect_contrast","1");
transformation.add(scale);

Map<String, Object> options=new HashMap();
options.put("path","/default-image.jpg");
options.put("transformation", transformation);
String url = ImageKit.getInstance().getUrl(options);

Note that because the src parameter was used, the transformation string gets added as a query parameter.

https://ik.imagekit.io/your_imagekit_id/default-image.jpg?tr=f-jpg&pr-true&e-sharpen&e-contrast-1&ik-sdk-version=java-1.0.3

3. Signed URL that expires in 300 seconds with the default URL endpoint and other query parameters

List<Map<String, String>> transformation=new ArrayList<Map<String, String>>();
Map<String, String> scale=new HashMap<>();
scale.put("height","600");
scale.put("width","400");

transformation.add(format);

Map<String, Object> options=new HashMap();
options.put("path","/default-image.jpg");
options.put("signed",true);
options.put("expireSeconds",300);
String url = ImageKit.getInstance().getUrl(options);

Sample Result URL

https://ik.imagekit.io/your_imagekit_id/tr:h-600,w-400/default-image.jpg?ik-t=1567358667&ik-s=f2c7cdacbe7707b71a83d49cf1c6110e3d701054&ik-sdk-version=java-1.0.3

List of transformations

The complete list of transformations supported and their usage in ImageKit can be found here. The SDK gives a name to each transformation parameter, making the code simpler, making the code more straightforward and readable. If a transformation is supported in ImageKit, but a name for it cannot be found in the table below, then use the transformation code from ImageKit docs as the name when using in the url function.

Supported Transformation Name	Translates to parameter
height	h
width	w
aspect_ratio	ar
quality	q
crop	c
crop_mode	cm
x	x
y	y
focus	fo
format	f
radius	r
background	bg
border	bo
rotation	rt
blur	bl
named	n
overlay_image	oi
overlay_x	ox
overlay_y	oy
overlay_focus	ofo
overlay_height	oh
overlay_width	ow
overlay_text	ot
overlay_text_font_size	ots
overlay_text_font_family	otf
overlay_text_color	otc
overlay_alpha	oa
overlay_text_typography	ott
overlay_background	obg
overlay_image_trim	oit
progressive	pr
lossless	lo
trim	t
metadata	md
color_profile	cp
default_image	di
dpr	dpr
effect_sharpen	e-sharpen
effect_usm	e-usm
effect_contrast	e-contrast
effect_gray	e-grayscale
original	orig

File Upload

The SDK provides a simple interface using the .upload() method to upload files to the ImageKit Media library. It accepts an object of FileCreateRequest class that contains all the parameters supported by the ImageKit Upload API.

The constructor FileCreateRequest class requires file as (URL/Base64/Byte Array) and file_name if file is byte array then it's require another parameter named mediaType to upload a file. The method returns object of Result class. It contains method isSuccessful() (return boolean), getMessage() for error message and other file parameter responsed by server. ImageKit upload API using the same parameter name as specified in the upload API documentation. For example, to specify tags for a file at the time of upload use the tags parameter as specified in the documentation here

Sample usage

String filePath = "your-local-file-path";
String base64 = Utils.fileToBase64(new File(filePath));
FileCreateRequest fileCreateRequest = new FileCreateRequest(base64, "file_name.jpg");
String customCoordinates = "10,10,20,20";
fileCreateRequest.setCustomCoordinates(customCoordinates);  // optional
List<String> tags = new ArrayList<>();
tags.add("Sample-tag");
tags.add("T-shirt");
fileCreateRequest.setTags(tags); // optional
fileCreateRequest.setFileName("override_file_name.jpg");  // optional
fileCreateRequest.setFolder("sample-folder/nested-folder");  // optional
fileCreateRequest.setPrivateFile(false);  // optional
fileCreateRequest.setUseUniqueFileName(true);  // optional
List<String> responseFields=new ArrayList<>();
responseFields.add("tags");
responseFields.add("customCoordinates");
fileCreateRequest.setResponseFields(responseFields); // optional
Result result = ImageKit.getInstance().upload(fileCreateRequest);
System.out.println("======FINAL RESULT=======");
System.out.println(result);
System.out.println("Raw Response:");
System.out.println(result.getRaw());
System.out.println("Map Response:");
System.out.println(result.getMap());

If the upload is successful, getMessage() will be None, and the result will be an object of Result class that contains the same all the parameters received from ImageKit's servers and isSuccessful() will return true.

If the upload fails, getMessage() will contain the same error message received from ImageKit's servers and isSuccessful() will return false.

File Management

The SDK provides a simple interface for all the media APIs mentioned here to manage your files. This also returns error and result, the error will be None if API succeeds.

1. List & Search Files

Accepts an object specifying the parameters to be used to list and search files. All parameters specified in the documentation here can be passed as-is with the correct values to get the results.

ResultList resultList=ImageKit.getInstance().getFileList(10,10);
System.out.println("======FINAL RESULT=======");
System.out.println(resultList);
System.out.println("Raw Response:");
System.out.println(resultList.getRaw());
System.out.println("Map Response:");
System.out.println(resultList.getMap());

2. Get File Details

Accepts the file ID and fetches the details as per the API documentation here

String fileId="your-file-id";
Result result=ImageKit.getInstance().getFileDetail(fileId);
System.out.println("======FINAL RESULT=======");
System.out.println(result);
System.out.println("Raw Response:");
System.out.println(result.getRaw());
System.out.println("Map Response:");
System.out.println(result.getMap());

3. Get File Metadata

Accepts the file ID and fetches the metadata as per the API documentation here

String fileId="your-file-id";
ResultMetaData result=ImageKit.getInstance().getFileMetadata(fileId);
System.out.println("======FINAL RESULT=======");
System.out.println(result);
System.out.println("Raw Response:");
System.out.println(result.getRaw());
System.out.println("Map Response:");
System.out.println(result.getMap());

Another way to get metadata from a remote file URL as per the API documentation here. This file should be accessible over the ImageKit.io URL-endpoint.

String url="Remote File URL";
ResultMetaData result=ImageKit.getInstance().getRemoteFileMetadata(url);
System.out.println("======FINAL RESULT=======");
System.out.println(result);
System.out.println("Raw Response:");
System.out.println(result.getRaw());
System.out.println("Map Response:");
System.out.println(result.getMap());

4. Update File Details

It updates the file properties as per the API documentation here. The argument to the updateDetail() method is the object of FileUpdateRequest class, and the constructor will take the file ID and then set the parameters to be updated.

String fileId="your-file-id";
FileUpdateRequest fileUpdateRequest =new FileUpdateRequest(fileId);
fileUpdateRequest.setTags(List.of("Software","Developer","Engineer"));
fileUpdateRequest.setCustomCoordinates("10,10,40,40");
Result result=ImageKit.getInstance().updateFileDetail(fileUpdateRequest);
System.out.println("======FINAL RESULT=======");
System.out.println(result);
System.out.println("Raw Response:");
System.out.println(result.getRaw());
System.out.println("Map Response:");
System.out.println(result.getMap());

5. Delete File

Delete a file as per the API documentation here. The method accepts the file ID of the file that has to be deleted.

String fileId="your-file-id";
Result result=ImageKit.getInstance().deleteFile(fileId);
System.out.println("======FINAL RESULT=======");
System.out.println(result);
System.out.println("Raw Response:");
System.out.println(result.getRaw());
System.out.println("Map Response:");
System.out.println(result.getMap());

6. Delete files (bulk)

Delete multiple files as per the API documentation here. The method accepts multiple file ID of the file that has to be deleted.

List<String> fileIds = new ArrayList<>();
fileIds.add("your-file-id");
fileIds.add("your-file-id");
fileIds.add("your-file-id");

ResultFileDelete result=ImageKit.getInstance().bulkDeleteFiles(fileIds);
System.out.println("======FINAL RESULT=======");
System.out.println(result);
System.out.println("Raw Response:");
System.out.println(result.getRaw());
System.out.println("Map Response:");
System.out.println(result.getMap());

7. Purge Cache

Programmatically issue a cache clear request as per the API documentation here. Accepts the full URL of the file for which the cache has to be cleared.

ResultCache result=ImageKit.getInstance().purgeCache("https://ik.imagekit.io/imagekit-id/default-image.jpg");
System.out.println("======FINAL RESULT=======");
System.out.println(result);
System.out.println("Raw Response:");
System.out.println(result.getRaw());
System.out.println("Map Response:");
System.out.println(result.getMap());

8. Purge Cache Status

Get the purge cache request status using the request ID returned when a purge cache request gets submitted as pet the API documentation here

String requestId="cache-requestId";
ResultCacheStatus result=ImageKit.getInstance().getPurgeCacheStatus(requestId);
System.out.println("======FINAL RESULT=======");
System.out.println(result);
System.out.println("Raw Response:");
System.out.println(result.getRaw());
System.out.println("Map Response:");
System.out.println(result.getMap());

Utility functions

We have included the following commonly used utility functions in this package.

Authentication parameter generation

In case you are looking to implement client-side file upload, you are going to need a token, expiry timestamp, and a valid signature for that upload. The SDK provides a simple method that you can use in your code to generate these authentication parameters for you.

Note: The Private API Key should never be exposed in any client-side code. You must always generate these authentications parameters on the server-side

authentication

Map<String,String> authenticationParams = ImageKit.getInstance().getAuthenticationParameters(token, expire);

Returns Map object of this json

{
    "token": "unique_token",
    "expire": "valid_expiry_timestamp",
    "signature": "generated_signature"
}

Both the token and expire parameters are optional. If not specified, the SDK uses the uuid to generate a random token and also generates a valid expiry timestamp internally. The value of the token and expire used to generate the signature are always returned in the response, no matter if they are provided as an input to this method or not.

Distance calculation between two pHash values

Perceptual hashing allows you to construct a hash value that uniquely identifies an input image based on the contents of an image. imagekit.io metadata API returns the pHash value of an image in the response. You can use this value to find a duplicate (or similar) images by calculating the distance between the two images.

This SDK exposes phash_distance function to calculate the distance between two pHash value. It accepts two pHash hexadecimal strings and returns a numeric value indicative of the level of difference between the two images.

int calculateDistance(){
    // fetch metadata of two uploaded image files
    ...
    // extract pHash strings from both: say 'first_hash' and 'second_hash'
    ...
    // calculate the distance between them:

    int distance = ImageKit.getInstance().pHashDistance(first_hash, second_hash);
    return distance;
}

Distance calculation examples

ImageKit.getInstance().pHashDistance("f06830ca9f1e3e90", "f06830ca9f1e3e90");
// output: 0 (ame image)

ImageKit.getInstance().pHashDistance("2d5ad3936d2e015b", "2d6ed293db36a4fb");
// output: 17 (similar images)

ImageKit.getInstance().pHashDistance("a4a65595ac94518b", "7838873e791f8400");
// output: 37 (dissimilar images)

Sample Code Instruction

1. First clone this repository to your system using git.

git clone https://github.com/imagekit-developer/imagekit-java.git

2. Open project in your favorite Java IDE that can supports Gradle dependency management or you can use Terminal/Command Prompt.

3. Goto src/main/resources directory.

4. Rename file config.sample.properties to config.properties.

5. Edit config.properties and write values of given keys.

UrlEndpoint=<-YOUR-ENDPOINT-URL-HERE->
PrivateKey=<-YOUR-PRIVATE-KEY-HERE->
PublicKey=<-YOUR-PUBLIC-KEY-HERE->

5. You will find App.java in src/main/java/io/imagekit/sampleapp/ directory. Edit program as you need, then run App.java. If you are using CLI Tool (Terminal/Command Prompt) Then Open Project in CLI and execute using gradle

cd imagekit-java
./gradlew run

• Run test case:

./gradlew imagekit-sdk:test

• Build ImageKit SDK:

./gradlew imagekit-sdk:clean
./gradlew imagekit-sdk:build
# You will find jar in "imagekit-sdk/build/libs/" directory.

Support

For any feedback or to report any issues or general implementation support, please reach out to support@imagekit.io

Links

• Documentation
• Main Website

License

Released under the MIT license.