[LANG-1563] use StandardCharsets.UTF_8 (#548)

* use_StandardCharsets_UTF_8

* Update StringEscapeUtilsTest.java

src/test/java/org/apache/commons/lang3/CharsetsTestCase.java

@@ -18,6 +18,7 @@
 package org.apache.commons.lang3;
 
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
@@ -31,14 +32,14 @@ public class CharsetsTestCase {
     public void testToCharset_Charset() {
         Assertions.assertEquals(Charset.defaultCharset(), Charsets.toCharset((Charset) null));
         Assertions.assertEquals(Charset.defaultCharset(), Charsets.toCharset(Charset.defaultCharset()));
-        Assertions.assertEquals(Charset.forName("UTF-8"), Charsets.toCharset(Charset.forName("UTF-8")));
+        Assertions.assertEquals(StandardCharsets.UTF_8, Charsets.toCharset(StandardCharsets.UTF_8));
     }
 
     @Test
     public void testToCharset_String() {
         Assertions.assertEquals(Charset.defaultCharset(), Charsets.toCharset((String) null));
         Assertions.assertEquals(Charset.defaultCharset(), Charsets.toCharset(Charset.defaultCharset().name()));
-        Assertions.assertEquals(Charset.forName("UTF-8"), Charsets.toCharset("UTF-8"));
+        Assertions.assertEquals(StandardCharsets.UTF_8, Charsets.toCharset("UTF-8"));
     }
 
     @Test

src/test/java/org/apache/commons/lang3/RandomStringUtilsTest.java

@@ -31,6 +31,7 @@ import static org.junit.jupiter.api.Assertions.fail;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Modifier;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Random;
 
 import org.junit.jupiter.api.Test;
@@ -488,7 +489,7 @@ public class RandomStringUtilsTest {
     @Test
     public void testLang100() {
         final int size = 5000;
-        final Charset charset = Charset.forName("UTF-8");
+        final Charset charset = StandardCharsets.UTF_8;
         final String orig = RandomStringUtils.random(size);
         final byte[] bytes = orig.getBytes(charset);
         final String copy = new String(bytes, charset);

src/test/java/org/apache/commons/lang3/StringEscapeUtilsTest.java

@@ -27,7 +27,6 @@ import java.io.IOException;
 import java.io.StringWriter;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Modifier;
-import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
@@ -479,7 +478,7 @@ public class StringEscapeUtilsTest {
         // codepoint: U+1D362
         final byte[] data = new byte[] { (byte) 0xF0, (byte) 0x9D, (byte) 0x8D, (byte) 0xA2 };
 
-        final String original = new String(data, Charset.forName("UTF8"));
+        final String original = new String(data, StandardCharsets.UTF_8);
 
         final String escaped = StringEscapeUtils.escapeHtml4( original );
         assertEquals(original, escaped, "High Unicode should not have been escaped");