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1   /*
2    * @(#) LDC.java Jan 8, 2004
3    * 
4    * Copyright (c) 2003 Delft University of Technology Jaffalaan 5, 2628 BX Delft,
5    * the Netherlands All rights reserved.
6    * 
7    * This software is proprietary information of Delft University of Technology
8    * The code is published under the General Public License
9    */
10  package nl.tudelft.simulation.dsol.interpreter.operations;
11  
12  import java.io.DataInput;
13  import java.io.IOException;
14  
15  import nl.tudelft.simulation.dsol.interpreter.LocalVariable;
16  import nl.tudelft.simulation.dsol.interpreter.OperandStack;
17  import nl.tudelft.simulation.dsol.interpreter.classfile.Constant;
18  import nl.tudelft.simulation.dsol.interpreter.classfile.ConstantFloat;
19  import nl.tudelft.simulation.dsol.interpreter.classfile.ConstantInteger;
20  import nl.tudelft.simulation.dsol.interpreter.classfile.ConstantString;
21  
22  /***
23   * The LDC operation as defined in <a
24   * href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/Instructions2.doc8.html">
25   * http://java.sun.com/docs/books/vmspec/2nd-edition/html/Instructions2.doc8.html
26   * </a>.
27   * <p>
28   * (c) copyright 2003 <a href="http://www.simulation.tudelft.nl">Delft
29   * University of Technology </a>, the Netherlands. <br>
30   * See for project information <a
31   * href="http://www.simulation.tudelft.nl">www.simulation.tudelft.nl </a> <br>
32   * License of use: <a href="http://www.gnu.org/copyleft/gpl.html">General Public
33   * License (GPL) </a>, no warranty <br>
34   * 
35   * @author <a href="http://www.tbm.tudelft.nl/webstaf/peterja/index.htm">Peter
36   *         Jacobs </a><a
37   *         href="http://www.tbm.tudelft.nl/webstaf/alexandv/index.htm">Alexander
38   *         Verbraeck </a>
39   * @version 1.3 Apr 6, 2004
40   * @since 1.4
41   */
42  public class LDC extends VoidOperation
43  {
44  	/*** OP refers to the operand code */
45  	public static final int OP = 18;
46  
47  	/*** the index to load */
48  	private int index = -1;
49  
50  	/***
51  	 * constructs a new LDC
52  	 * 
53  	 * @param dataInput the dataInput
54  	 * @throws IOException on IOfailure
55  	 */
56  	public LDC(final DataInput dataInput) throws IOException
57  	{
58  		super();
59  		this.index = dataInput.readUnsignedByte();
60  	}
61  
62  	/***
63  	 * @see nl.tudelft.simulation.dsol.interpreter.operations.VoidOperation#execute(
64  	 *      nl.tudelft.simulation.dsol.interpreter.OperandStack,
65  	 *      nl.tudelft.simulation.dsol.interpreter.classfile.Constant[],
66  	 *      nl.tudelft.simulation.dsol.interpreter.LocalVariable[])
67  	 */
68  	public void execute(final OperandStack stack,
69  			final Constant[] constantPool, final LocalVariable[] localVariables)
70  	{
71  		Constant constant = constantPool[this.index];
72  		if (constant instanceof ConstantInteger)
73  		{
74  			stack.push(new Integer(((ConstantInteger) constant).getValue()));
75  		} else if (constant instanceof ConstantFloat)
76  		{
77  			stack.push(new Float(((ConstantFloat) constant).getValue()));
78  		} else if (constant instanceof ConstantString)
79  		{
80  			stack.push(((ConstantString) constant).getValue());
81  		}
82  	}
83  
84  	/***
85  	 * @see nl.tudelft.simulation.dsol.interpreter.Operation#getByteLength()
86  	 */
87  	public int getByteLength()
88  	{
89  		return OPCODE_BYTE_LENGTH + 1;
90  	}
91  
92  	/***
93  	 * @see nl.tudelft.simulation.dsol.interpreter.Operation#getOpcode()
94  	 */
95  	public int getOpcode()
96  	{
97  		return LDC.OP;
98  	}
99  }