[IO-324] Add Charset sister APIs to method that take a String charset name.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/io/trunk@1326613 13f79535-47bb-0310-9956-ffa450edef68

Author: garydgregory

src/test/java/org/apache/commons/io/FileUtilsTestCase.java

@@ -24,6 +24,7 @@
 import java.io.IOException;
 import java.io.OutputStream;
 import java.net.URL;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -1550,6 +1551,13 @@ public void testWriteStringToFile2() throws Exception {
         assertEqualContent(text, file);
     }
 
+    public void testWriteStringToFile3() throws Exception {
+        File file = new File(getTestDirectory(), "write.txt");
+        FileUtils.writeStringToFile(file, "Hello /u1234", (Charset)null);
+        byte[] text = "Hello /u1234".getBytes();
+        assertEqualContent(text, file);
+    }
+
     public void testWriteCharSequence1() throws Exception {
         File file = new File(getTestDirectory(), "write.txt");
         FileUtils.write(file, "Hello /u1234", "UTF8");