Data URI Utility

Introduction

I have on occasion had to convert an image, usually an icon into a data URI to embed in a web application. I was looking for a simple application to perform the conversion, but usually they are included in larger frameworks.

I wrote a quick conversion utility as shown below.

The code can be found in the commons-utils project on GitHub.

Code

package com.example.uri;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.Base64;

/**
 *
 * @author John Yeary <jyeary@bluelotussoftware.com>
 */
public final class Utils {

    /**
     * Convert a file into base 64 encoded URI.Primarily used for creating
     * encoded images to be displayed inline in HTML.
     *
     * @param file The file to be converted into a data URI.
     * @return A base 64 encoded representation of the the file in a data URI
     * format.
     * @throws IOException If an exception occurs during processing of the file.
     */
    public static String toDataURI(final File file) throws IOException {
        // Check content type of the file
        String contentType = Files.probeContentType(file.toPath());

        // Read data as byte[]
        byte[] data = Files.readAllBytes(file.toPath());
        
        // Convert byte[] to base64
        String encoded = Base64.getEncoder().encodeToString(data);

        // Create "data URI"
        StringBuilder sb = new StringBuilder();
        sb.append("data:");
        sb.append(contentType);
        sb.append(";base64,");
        sb.append(encoded);
        return sb.toString();
    }

}

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