Add test for UrlUtil#openStream method

DEVSIX-3683

Author: yulian-gaponenko

io/src/test/java/com/itextpdf/io/util/UrlUtilTest.java

@@ -46,6 +46,10 @@ This file is part of the iText (R) project.
 import com.itextpdf.test.annotations.type.UnitTest;
 import java.io.File;
 import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Paths;
 import org.junit.Assert;
 import org.junit.BeforeClass;
@@ -86,4 +90,14 @@ public void nullBaseUriTest() throws IOException {
         File tempFile = null;
         Assert.assertEquals(expected, FileUtil.getParentDirectory(tempFile));
     }
+
+    @Test
+    public void openStreamTest() throws IOException {
+        String resPath = "./src/test/resources/com/itextpdf/io/util/textFile.dat";
+        InputStream openStream = UrlUtil.openStream(new File(resPath).toURI().toURL());
+
+        String actual = new String(StreamUtil.inputStreamToArray(openStream), StandardCharsets.UTF_8);
+        Assert.assertEquals("Hello world from text file!", actual);
+
+    }
 }

io/src/test/resources/com/itextpdf/io/util/textFile.dat

@@ -0,0 +1 @@
+Hello world from text file!