archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-08-26 22:34:27 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

8191706: Add Reader::transferTo(Writer)

Browse source 
Reviewed-by: alanb, bpb, briangoetz
This commit is contained in:
Patrick Reinhart 2017-12-06 14:39:15 -08:00 • committed by Brian Burkhalter
parent a53a1b7844
commit 5eafe731b0
2 changed files with 395 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

43
src/java.base/share/classes/java/io/Reader.java
View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 1996, 2012, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1996, 2017, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@ -26,6 +26,8 @@
package java.io;
import java.util.Objects;
/**
* Abstract class for reading character streams. The only methods that a
* subclass must implement are read(char[], int, int) and close(). Most
@ -50,6 +52,8 @@ package java.io;
public abstract class Reader implements Readable, Closeable {
private static final int TRANSFER_BUFFER_SIZE = 8192;
/**
* The object used to synchronize operations on this stream. For
* efficiency, a character-stream object may use an object other than
@ -262,4 +266,41 @@ public abstract class Reader implements Readable, Closeable {
*/
public abstract void close() throws IOException;
/**
* Reads all characters from this reader and writes the characters to the
* given writer in the order that they are read. On return, this reader
* will be at end of the stream. This method does not close either reader
* or writer.
* <p>
* This method may block indefinitely reading from the reader, or
* writing to the writer. The behavior for the case where the reader
* and/or writer is <i>asynchronously closed</i>, or the thread
* interrupted during the transfer, is highly reader and writer
* specific, and therefore not specified.
* <p>
* If an I/O error occurs reading from the reader or writing to the
* writer, then it may do so after some characters have been read or
* written. Consequently the reader may not be at end of the stream and
* one, or both, streams may be in an inconsistent state. It is strongly
* recommended that both streams be promptly closed if an I/O error occurs.
*
* @param out the writer, non-null
* @return the number of characters transferred
* @throws IOException if an I/O error occurs when reading or writing
* @throws NullPointerException if {@code out} is {@code null}
*
* @since 10
*/
public long transferTo(Writer out) throws IOException {
Objects.requireNonNull(out, "out");
long transferred = 0;
char[] buffer = new char[TRANSFER_BUFFER_SIZE];
int nRead;
while ((nRead = read(buffer, 0, TRANSFER_BUFFER_SIZE)) >= 0) {
out.write(buffer, 0, nRead);
transferred += nRead;
}
return transferred;
}
}