Port some code from IO to NIO APIs

Author: garydgregory

src/test/java/org/apache/commons/csv/CSVPrinterTest.java

@@ -41,6 +41,8 @@
 import java.io.Writer;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.sql.BatchUpdateException;
 import java.sql.Connection;
 import java.sql.DriverManager;
@@ -92,6 +94,14 @@ private static String printable(final String s) {
 
     private final String recordSeparator = CSVFormat.DEFAULT.getRecordSeparator();
 
+    private File createTempFile() throws IOException {
+        return createTempPath().toFile();
+    }
+
+    private Path createTempPath() throws IOException {
+        return Files.createTempFile(getClass().getName(), ".csv");
+    }
+
     private void doOneRandom(final CSVFormat format) throws Exception {
         final Random r = new Random();
 
@@ -1543,7 +1553,7 @@ public void testPrintRecordsWithResultSetOneRow() throws IOException, SQLExcepti
 
     @Test
     public void testPrintToFileWithCharsetUtf16Be() throws IOException {
-        final File file = File.createTempFile(getClass().getName(), ".csv");
+        final File file = createTempFile();
         try (final CSVPrinter printer = CSVFormat.DEFAULT.print(file, StandardCharsets.UTF_16BE)) {
             printer.printRecord("a", "b\\c");
         }
@@ -1552,7 +1562,7 @@ public void testPrintToFileWithCharsetUtf16Be() throws IOException {
 
     @Test
     public void testPrintToFileWithDefaultCharset() throws IOException {
-        final File file = File.createTempFile(getClass().getName(), ".csv");
+        final File file = createTempFile();
         try (final CSVPrinter printer = CSVFormat.DEFAULT.print(file, Charset.defaultCharset())) {
             printer.printRecord("a", "b\\c");
         }
@@ -1561,11 +1571,11 @@ public void testPrintToFileWithDefaultCharset() throws IOException {
 
     @Test
     public void testPrintToPathWithDefaultCharset() throws IOException {
-        final File file = File.createTempFile(getClass().getName(), ".csv");
-        try (final CSVPrinter printer = CSVFormat.DEFAULT.print(file.toPath(), Charset.defaultCharset())) {
+        final Path file = createTempPath();
+        try (final CSVPrinter printer = CSVFormat.DEFAULT.print(file, Charset.defaultCharset())) {
             printer.printRecord("a", "b\\c");
         }
-        assertEquals("a,b\\c" + recordSeparator, FileUtils.readFileToString(file, Charset.defaultCharset()));
+        assertEquals("a,b\\c" + recordSeparator, new String(Files.readAllBytes(file), Charset.defaultCharset()));
     }
 
     @Test