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/*
* Copyright (c) 2010, 2013, 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
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package jdk.nashorn.api.scripting;
import java.io.CharArrayReader;
import java.io.IOException;
import java.io.Reader;
import java.net.URL;
import java.nio.charset.Charset;
import jdk.nashorn.internal.runtime.Source;
/**
* A Reader that reads from a URL. Used to make sure that the reader
* reads content from given URL and can be trusted to do so.
*/
public final class URLReader extends Reader {
// underlying URL
private final URL url;
// Charset used to convert
private final Charset cs;
// lazily initialized underlying reader for URL
private Reader reader;
/**
* Constructor
*
* @param url URL for this URLReader
* @throws NullPointerException if url is null
*/
public URLReader(final URL url) {
this(url, (Charset)null);
}
/**
* Constructor
*
* @param url URL for this URLReader
* @param charsetName Name of the Charset used to convert bytes to chars
* @throws NullPointerException if url is null
*/
public URLReader(final URL url, final String charsetName) {
this(url, Charset.forName(charsetName));
}
/**
* Constructor
*
* @param url URL for this URLReader
* @param cs Charset used to convert bytes to chars
* @throws NullPointerException if url is null
*/
public URLReader(final URL url, final Charset cs) {
// null check
url.getClass();
this.url = url;
this.cs = cs;
}
@Override
public int read(final char cbuf[], final int off, final int len) throws IOException {
return getReader().read(cbuf, off, len);
}
@Override
public void close() throws IOException {
getReader().close();
}
/**
* URL of this reader
* @return the URL from which this reader reads.
*/
public URL getURL() {
return url;
}
/**
* Charset used by this reader
*
* @return the Chartset used to convert bytes to chars
*/
public Charset getCharset() {
return cs;
}
// lazily initialize char array reader using URL content
private Reader getReader() throws IOException {
synchronized (lock) {
if (reader == null) {
reader = new CharArrayReader(Source.readFully(url, cs));
}
}
return reader;
}
}
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