1 /*
   2  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.nashorn.api.scripting;
  27 
  28 import java.io.CharArrayReader;
  29 import java.io.IOException;
  30 import java.io.Reader;
  31 import java.net.URL;
  32 import java.nio.charset.Charset;
  33 import java.util.Objects;
  34 import jdk.nashorn.internal.runtime.Source;
  35 
  36 /**
  37  * A Reader that reads from a URL. Used to make sure that the reader
  38  * reads content from given URL and can be trusted to do so.
  39  *
  40  * @deprecated Nashorn JavaScript script engine and APIs, and the jjs tool 
  41  * are deprecated with the intent to remove them in a future release.
  42  *
  43  * @since 1.8u40
  44  */
  45 @Deprecated(since="11", forRemoval=true)
  46 public final class URLReader extends Reader {
  47     // underlying URL
  48     private final URL url;
  49     // Charset used to convert
  50     private final Charset cs;
  51 
  52     // lazily initialized underlying reader for URL
  53     private Reader reader;
  54 
  55     /**
  56      * Constructor
  57      *
  58      * @param url URL for this URLReader
  59      * @throws NullPointerException if url is null
  60      */
  61     public URLReader(final URL url) {
  62         this(url, (Charset)null);
  63     }
  64 
  65     /**
  66      * Constructor
  67      *
  68      * @param url URL for this URLReader
  69      * @param charsetName  Name of the Charset used to convert bytes to chars
  70      * @throws NullPointerException if url is null
  71      */
  72     public URLReader(final URL url, final String charsetName) {
  73         this(url, Charset.forName(charsetName));
  74     }
  75 
  76     /**
  77      * Constructor
  78      *
  79      * @param url URL for this URLReader
  80      * @param cs  Charset used to convert bytes to chars
  81      * @throws NullPointerException if url is null
  82      */
  83     public URLReader(final URL url, final Charset cs) {
  84         this.url = Objects.requireNonNull(url);
  85         this.cs  = cs;
  86     }
  87 
  88     @Override
  89     public int read(final char cbuf[], final int off, final int len) throws IOException {
  90         return getReader().read(cbuf, off, len);
  91     }
  92 
  93     @Override
  94     public void close() throws IOException {
  95         getReader().close();
  96     }
  97 
  98     /**
  99      * URL of this reader
 100      * @return the URL from which this reader reads.
 101      */
 102     public URL getURL() {
 103         return url;
 104     }
 105 
 106     /**
 107      * Charset used by this reader
 108      *
 109      * @return the Charset used to convert bytes to chars
 110      */
 111     public Charset getCharset() {
 112         return cs;
 113     }
 114 
 115     // lazily initialize char array reader using URL content
 116     private Reader getReader() throws IOException {
 117         synchronized (lock) {
 118             if (reader == null) {
 119                 reader = new CharArrayReader(Source.readFully(url, cs));
 120             }
 121         }
 122 
 123         return reader;
 124     }
 125 }