Update Java example (#498)

examples/signature.java

@@ -1,51 +1,57 @@
 package imgproxytest;
 
-import com.amazonaws.util.Base16;
-import org.apache.commons.codec.binary.Base64;
-import org.junit.Assert;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
+
+import java.util.Base64;
 
 import javax.crypto.Mac;
 import javax.crypto.spec.SecretKeySpec;
 
-public class imgproxy {
+import static org.junit.jupiter.api.Assertions.*;
 
+public class ImgProxy{
+    
     @Test
     public void testWithJavaHmacApacheBase64ImgProxyTest() throws Exception {
-
-        String Key = "943b421c9eb07c830af81030552c86009268de4e532ba2ee2eab8247c6da0881";
-        String Salt = "520f986b998545b4785e0defbc4f3c1203f22de2374a3d53cb7a7fe9fea309c5";
-        String Url = "http://img.example.com/pretty/image.jpg";
-
-        String Resize = "fill";
-        int Width = 300;
-        int Height = 300;
-        String Gravity = "no";
-        int Enlarge = 1;
-        String Extension = "png";
-        String urlWithHash = GenerateSignedUrlImgProxy(Key, Salt, Url, Resize, Width, Height, Gravity, Enlarge, Extension);
-
-        Assert.assertEquals("/_PQ4ytCQMMp-1w1m_vP6g8Qb-Q7yF9mwghf6PddqxLw/fill/300/300/no/1/aHR0cDovL2ltZy5leGFtcGxlLmNvbS9wcmV0dHkvaW1hZ2UuanBn.png", urlWithHash);
+        byte[] key = hexStringToByteArray("943b421c9eb07c830af81030552c86009268de4e532ba2ee2eab8247c6da0881");
+        byte[] salt = hexStringToByteArray("520f986b998545b4785e0defbc4f3c1203f22de2374a3d53cb7a7fe9fea309c5");
+        String url = "http://img.example.com/pretty/image.jpg";
+
+        String resize = "fill";
+        int width = 300;
+        int height = 300;
+        String gravity = "no";
+        int enlarge = 1;
+        String extension = "png";
+        String urlWithHash = generateSignedUrlForImgProxy(key, salt, url, resize, width, height, gravity, enlarge, extension);
+
+        assertEquals("/_PQ4ytCQMMp-1w1m_vP6g8Qb-Q7yF9mwghf6PddqxLw/fill/300/300/no/1/aHR0cDovL2ltZy5leGFtcGxlLmNvbS9wcmV0dHkvaW1hZ2UuanBn.png", urlWithHash);
     }
 
-
-    public static String GenerateSignedUrlImgProxy(String key, String salt, String url, String resize, int width, int height, String gravity, int enlarge, String extension) throws Exception {
+    public static String generateSignedUrlForImgProxy(byte[] key, byte[] salt, String url, String resize, int width, int height, String gravity, int enlarge, String extension) throws Exception {
         final String HMACSHA256 = "HmacSHA256";
 
-        byte[] keybin = Base16.decode(key);
-        byte[] saltBin = Base16.decode(salt);
-
-        String encodedUrl = Base64.encodeBase64URLSafeString(url.getBytes());
+        String encodedUrl = Base64.getUrlEncoder().withoutPadding().encodeToString(url.getBytes());
 
         String path = "/" + resize + "/" + width + "/" + height + "/" + gravity + "/" + enlarge + "/" + encodedUrl + "." + extension;
 
-        Mac sha256_HMAC = Mac.getInstance(HMACSHA256);
-        SecretKeySpec secret_key = new SecretKeySpec(keybin, HMACSHA256);
-        sha256_HMAC.init(secret_key);
-        sha256_HMAC.update(saltBin);
+        Mac sha256HMAC = Mac.getInstance(HMACSHA256);
+        SecretKeySpec secretKey = new SecretKeySpec(key, HMACSHA256);
+        sha256HMAC.init(secretKey);
+        sha256HMAC.update(salt);
 
-        String hash = Base64.encodeBase64URLSafeString(sha256_HMAC.doFinal(path.getBytes()));
+        String hash = Base64.getUrlEncoder().withoutPadding().encodeToString(sha256HMAC.doFinal(path.getBytes()));
 
         return "/" + hash + path;
     }
+
+    private static byte[] hexStringToByteArray(String hex){
+        if (hex.length() % 2 != 0)
+            throw new IllegalArgumentException("Even-length string required");
+        byte[] res = new byte[hex.length() / 2];
+        for (int i = 0; i < res.length; i++) {
+            res[i]=(byte)((Character.digit(hex.charAt(i * 2), 16) << 4) | (Character.digit(hex.charAt(i * 2 + 1), 16)));
+        }
+        return res;
+    }
 }