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Java > Open Source Codes > org > jruby > util > IOInputStream


1 /***** BEGIN LICENSE BLOCK *****
2  * Version: CPL 1.0/GPL 2.0/LGPL 2.1
3  *
4  * The contents of this file are subject to the Common Public
5  * License Version 1.0 (the "License"); you may not use this file
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7  * the License at http://www.eclipse.org/legal/cpl-v10.html
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14  * Copyright (C) 2006 Ola Bini <Ola.Bini@ki.se>
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28 package org.jruby.util;
29
30 import java.io.InputStream JavaDoc;
31 import java.io.IOException JavaDoc;
32
33 import org.jruby.RubyFixnum;
34 import org.jruby.RubyString;
35 import org.jruby.runtime.builtin.IRubyObject;
36
37 /**
38  * This class wraps a IRubyObject in an InputStream. Depending on which messages
39  * the IRubyObject answers to, it will have different functionality.
40  *
41  * The point is that the IRubyObject could exhibit duck typing, in the style of IO versus StringIO, for example.
42  *
43  * At the moment, the only functionality supported is reading, and the only requirement on the io-object is
44  * that it responds to read() like IO.
45  */
46 public class IOInputStream extends InputStream JavaDoc {
47     private IRubyObject io;
48     private final IRubyObject numOne;
49
50     /**
51      * Creates a new InputStream with the object provided.
52      *
53      * @param io the ruby object
54      */
55     public IOInputStream(IRubyObject io) {
56         if (!io.respondsTo("read")) {
57             throw new IllegalArgumentException JavaDoc("Object: " + io + " is not a legal argument to this wrapper, cause it doesn't respond to \"read\".");
58         }
59         this.io = io;
60         this.numOne = RubyFixnum.one(this.io.getRuntime());
61     }
62     
63     public int read() throws IOException JavaDoc {
64         IRubyObject readValue = io.callMethod(io.getRuntime().getCurrentContext(), "read", numOne);
65         int returnValue = -1;
66         if (!readValue.isNil()) {
67             returnValue = readValue.toString().charAt(0);
68         }
69         return returnValue;
70     }
71
72     public int read(byte[] b) throws IOException JavaDoc {
73         IRubyObject readValue = io.callMethod(io.getRuntime().getCurrentContext(), "read", this.io.getRuntime().newFixnum(b.length));
74         int returnValue = -1;
75         if (!readValue.isNil()) {
76             ByteList str = ((RubyString)readValue).getByteList();
77             System.arraycopy(str.bytes,0,b,0,str.realSize);
78             returnValue = str.realSize;
79         }
80         return returnValue;
81     }
82
83     public int read(byte[] b, int off, int len) throws IOException JavaDoc {
84         IRubyObject readValue = io.callMethod(io.getRuntime().getCurrentContext(), "read", io.getRuntime().newFixnum(len));
85         int returnValue = -1;
86         if (!readValue.isNil()) {
87             ByteList str = ((RubyString)readValue).getByteList();
88             System.arraycopy(str.bytes,0,b,off,str.realSize);
89             returnValue = str.realSize;
90         }
91         return returnValue;
92      }
93 }
94
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