review patch java.io.Ouputs

[Rémi Forax]

Ok, i've re-applied my changes to Ouputs.java,
there is no more change to Inputs.java until
java.util.Scanner is not changed.

All writeLines now use a List<? extends CharSequence> instead of a 
List<String>.

I've added methods
- writeLines(FileRef file, List<? extends CharSequence> lines, Charset 
charset)
- writeLines(File file, List<? extends CharSequence> lines, Charset charset)
- writeLines(OutputStream out, List<? extends CharSequence> lines, 
Charset charset)
they all use ensureCharsetIsNotNull that performs a null check.

I've rewritten all methods that use Charset.defaultCharset().name()
to use Charset.defaultCharset().

I've also noted that writeLines(OutputStream out, List<String> lines, 
String csn)
(now writeLines(OutputStream out, List<? extends CharSequence> lines, 
String csn))
currently doesn't call ensureCharsetIsSupported so I've fix that too.

Rémi

Here is the patch:

diff --git a/src/share/classes/java/io/Outputs.java 
b/src/share/classes/java/io/Outputs.java
--- a/src/share/classes/java/io/Outputs.java
+++ b/src/share/classes/java/io/Outputs.java
@@ -57,6 +57,12 @@ public final class Outputs {
         if (!Charset.isSupported(csn))
             throw new UnsupportedCharsetException(csn);
     }
+    
+    // checks that charset is not null
+    private static void ensureCharsetIsNotNull(Charset charset) {
+      if (charset == null)
+        throw new NullPointerException("'charset' is null");
+    }
 
     /**
      * Writes a byte array to a file. The file is created if it does 
not exist.
@@ -105,6 +111,40 @@ public final class Outputs {
      *          The file
      * @param   lines
      *          The list of lines to write (in order)
+     * @param   charset
+     *          The charset to be used
+     *
+     * @throws  java.nio.charset.UnsupportedCharsetException
+     *          If no support for the named charset is available
+     *          in this instance of the Java virtual machine
+     * @throws  java.nio.charset.UnmappableCharacterException
+     *          Where a line contains a character that cannot be mapped 
to an
+     *          output byte sequence
+     * @throws  IOException
+     *          If an I/O error occurs
+     */
+    public static void writeLines(FileRef file, List<? extends 
CharSequence> lines, Charset charset)
+        throws IOException
+    {
+        ensureCharsetIsNotNull(charset);
+        WritableByteChannel wbc = file.newByteChannel(WRITE, CREATE, 
TRUNCATE_EXISTING);
+        BufferedWriter writer = new 
BufferedWriter(Channels.newWriter(wbc, charset.newEncoder(), -1));
+        try {
+            implWriteLines(writer, lines);
+        } finally {
+            writer.close();
+        }
+    }
+    
+    /**
+     * Writes the given lines of text to the specified file. The 
characters in
+     * each line are encoded into bytes using the specified charset. 
When all
+     * lines have been written, or an I/O error occurs, then the file 
is closed.
+     *
+     * @param   file
+     *          The file
+     * @param   lines
+     *          The list of lines to write (in order)
      * @param   csn
      *          The name of the charset to be used
      *
@@ -117,7 +157,7 @@ public final class Outputs {
      * @throws  IOException
      *          If an I/O error occurs
      */
-    public static void writeLines(FileRef file, List<String> lines, 
String csn)
+    public static void writeLines(FileRef file, List<? extends 
CharSequence> lines, String csn)
         throws IOException
     {
         ensureCharsetIsSupported(csn);
@@ -147,10 +187,10 @@ public final class Outputs {
      * @throws  IOException
      *          If an I/O error occurs
      */
-    public static void writeLines(FileRef file, List<String> lines)
-        throws IOException
-    {
-        writeLines(file, lines, Charset.defaultCharset().name());
+    public static void writeLines(FileRef file, List<? extends 
CharSequence> lines)
+        throws IOException
+    {
+        writeLines(file, lines, Charset.defaultCharset());
     }
 
     /**
@@ -170,10 +210,10 @@ public final class Outputs {
      * @throws  IOException
      *          If an I/O error occurs
      */
-    public static void writeLines(FileRef file, String... lines)
-        throws IOException
-    {
-        writeLines(file, Arrays.asList(lines), 
Charset.defaultCharset().name());
+    public static void writeLines(FileRef file, CharSequence... lines)
+        throws IOException
+    {
+        writeLines(file, Arrays.asList(lines), Charset.defaultCharset());
     }
 
     /**
@@ -222,6 +262,40 @@ public final class Outputs {
      *          The file
      * @param   lines
      *          The list of lines to write (in order)
+     * @param   charset
+     *          The charset to be used
+     *
+     * @throws  java.nio.charset.UnsupportedCharsetException
+     *          If no support for the named charset is available
+     *          in this instance of the Java virtual machine
+     * @throws  java.nio.charset.UnmappableCharacterException
+     *          Where a line contains a character that cannot be mapped 
to an
+     *          output byte sequence
+     * @throws  IOException
+     *          If an I/O error occurs
+     */
+    public static void writeLines(File file, List<? extends 
CharSequence> lines, Charset charset)
+        throws IOException
+    {
+        ensureCharsetIsNotNull(charset);
+        FileOutputStream out = new FileOutputStream(file);
+        BufferedWriter writer = new BufferedWriter(new 
OutputStreamWriter(out, charset));
+        try {
+            implWriteLines(writer, lines);
+        } finally {
+            writer.close();
+        }
+    }
+    
+    /**
+     * Writes the given lines of text to the specified file. The 
characters in
+     * each line are encoded into bytes using the specified charset. 
When all
+     * lines have been written, or an I/O error occurs, then the file 
is closed.
+     *
+     * @param   file
+     *          The file
+     * @param   lines
+     *          The list of lines to write (in order)
      * @param   csn
      *          The name of the charset to be used
      *
@@ -234,7 +308,7 @@ public final class Outputs {
      * @throws  IOException
      *          If an I/O error occurs
      */
-    public static void writeLines(File file, List<String> lines, String 
csn)
+    public static void writeLines(File file, List<? extends 
CharSequence> lines, String csn)
         throws IOException
     {
         ensureCharsetIsSupported(csn);
@@ -264,10 +338,10 @@ public final class Outputs {
      * @throws  IOException
      *          If an I/O error occurs
      */
-    public static void writeLines(File file, List<String> lines)
-        throws IOException
-    {
-        writeLines(file, lines, Charset.defaultCharset().name());
+    public static void writeLines(File file, List<? extends 
CharSequence> lines)
+        throws IOException
+    {
+        writeLines(file, lines, Charset.defaultCharset());
     }
 
     /**
@@ -287,10 +361,10 @@ public final class Outputs {
      * @throws  IOException
      *          If an I/O error occurs
      */
-    public static void writeLines(File file, String... lines)
-        throws IOException
-    {
-        writeLines(file, Arrays.asList(lines), 
Charset.defaultCharset().name());
+    public static void writeLines(File file, CharSequence... lines)
+        throws IOException
+    {
+        writeLines(file, Arrays.asList(lines), Charset.defaultCharset());
     }
 
     /**
@@ -301,18 +375,48 @@ public final class Outputs {
      *          The output stream
      * @param   lines
      *          The list of lines to write (in order)
+     * @param   charset
+     *          The charset to be used
+     *
+     * @throws  java.nio.charset.UnmappableCharacterException
+     *          Where a line contains a character that cannot be mapped 
to an
+     *          output byte sequence
+     * @throws  IOException
+     *          If an I/O error occurs
+     */
+    public static void writeLines(OutputStream out, List<? extends 
CharSequence> lines, Charset charset)
+        throws IOException
+    {
+        ensureCharsetIsNotNull(charset);
+        BufferedWriter writer = new BufferedWriter(new 
OutputStreamWriter(out, charset));
+        implWriteLines(writer, lines);
+        writer.flush();
+    }
+    
+    /**
+     * Writes the given lines of text to the specified output stream. The
+     * characters in each line are encoded into bytes using the 
specified charset.
+     *
+     * @param   out
+     *          The output stream
+     * @param   lines
+     *          The list of lines to write (in order)
      * @param   csn
      *          The name of the charset to be used
      *
-     * @throws  java.nio.charset.UnmappableCharacterException
-     *          Where a line contains a character that cannot be mapped 
to an
-     *          output byte sequence
-     * @throws  IOException
-     *          If an I/O error occurs
-     */
-    public static void writeLines(OutputStream out, List<String> lines, 
String csn)
-        throws IOException
-    {
+     * @throws  java.nio.charset.UnsupportedCharsetException
+     *          If no support for the named charset is available
+     *          in this instance of the Java virtual machine
+     * @throws  java.nio.charset.UnmappableCharacterException
+     *          Where a line contains a character that cannot be mapped 
to an
+     *          output byte sequence
+     * @throws  IOException
+     *          If an I/O error occurs
+     */
+    public static void writeLines(OutputStream out, List<? extends 
CharSequence> lines, String csn)
+        throws IOException
+    {
+        ensureCharsetIsSupported(csn);
         BufferedWriter writer = new BufferedWriter(new 
OutputStreamWriter(out, csn));
         implWriteLines(writer, lines);
         writer.flush();
@@ -334,17 +438,17 @@ public final class Outputs {
      * @throws  IOException
      *          If an I/O error occurs
      */
-    public static void writeLines(OutputStream out, List<String> lines)
-        throws IOException
-    {
-        writeLines(out, lines, Charset.defaultCharset().name());
-    }
-
-    private static void implWriteLines(BufferedWriter writer, 
List<String> lines)
-        throws IOException
-    {
-        for (String line: lines) {
-            writer.write(line);
+    public static void writeLines(OutputStream out, List<? extends 
CharSequence> lines)
+        throws IOException
+    {
+        writeLines(out, lines, Charset.defaultCharset());
+    }
+
+    private static void implWriteLines(BufferedWriter writer, List<? 
extends CharSequence> lines)
+        throws IOException
+    {
+        for (CharSequence line: lines) {
+            writer.write(line.toString());
             writer.newLine();
         }
     }