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ConstantDoubleInfo.javaAPI DocJ2ME CLDC 1.12465Wed Feb 05 15:56:04 GMT 2003kdp.classparser.constantpoolclasses

ConstantDoubleInfo

public class ConstantDoubleInfo extends ConstantPoolInfo
Encapsulates a CONSTANT_Double in a Java class file constant pool.
author
Aaron Dietrich
version
$Id: ConstantDoubleInfo.java,v 1.1.1.1 2000/07/07 13:34:24 jrv Exp $ Revision History $Log: ConstantDoubleInfo.java,v $ Revision 1.1.1.1 2000/07/07 13:34:24 jrv Initial import of kdp code Revision 1.1.1.1 2000/05/31 19:14:48 ritsun Initial import of kvmdt to CVS Revision 1.1 2000/04/25 00:34:06 ritsun Initial revision

Fields Summary
private int
highBytes
The high bytes of this double
private int
lowBytes
The low bytes of this double
Constructors Summary
public ConstantDoubleInfo(DataInputStream iStream)
Constructor. Reads in appropriate data.

param
iStream input stream to read from
exception
IOException just pass IOExceptions up

      tag = ConstantPoolInfo.CONSTANT_Double;

      highBytes = iStream.readInt ();
      lowBytes = iStream.readInt ();
Methods Summary
public java.lang.StringtoString()
Returns the value of this double as a string by converting the high and low bytes to a double using the method specified in the JVM Specification.

return
String The double as a string.

      long          longValue = ((long) highBytes << 32) + lowBytes;

      if (longValue == 0x7ff0000000000000L)
        return ("CONSTANT_Double=\t" + "Positive Infinity");

      if (longValue == 0xfff0000000000000L)
        return ("CONSTANT_Double=\t" + "Negative Infinity");

      if (((longValue >= 0x7ff0000000000001L) && (longValue <= 0x7fffffffffffffffL)) ||
          ((longValue >= 0xfff0000000000001L) && (longValue <= 0xffffffffffffffffL)))
        return ("CONSTANT_Double=\t" + "NaN");

      int s = ((longValue >> 63) == 0) ? 1 : -1;
      int e = (int)((longValue >> 52) & 0x7ffL);
      long m = (e == 0) ? (longValue & 0xfffffffffffffL) << 1 :
                          (longValue & 0xfffffffffffffL) | 0x10000000000000L;

      double value = s * m * (2^(e - 1075));

      return ("CONSTANT_Double=\t" + value);