integer.java

轻量嵌入JVM,可用于掌上设备手机等手持消息设备．

/************************************************************************
This file is part of java core libraries for the simpleRTJ virtual machine.

This file is covered by the GNU GPL with the following exception:
  As a special exception, the copyright holders of this library give you permission
  to link this library with independent modules to produce an executable, regardless
  of the license terms of these independent modules, and to copy and distribute the
  resulting executable under terms of your choice, provided that you also meet, for
  each linked independent module, the terms and conditions of the license of that
  module. An independent module is a module which is not derived from or based on
  this library. If you modify this library, you may extend this exception to your
  version of the library, but you are not obligated to do so. If you do not wish
  to do so, delete this exception statement from your version.


THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY,  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL RTJ COMPUTING BE LIABLE FOR ANY CLAIM, DAMAGES
OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Created/modified by:
    RTJ Computing
***********************************************************************/
package java.lang;


/**
 * Encapsulates <strong>int</strong> java primitive type.
 *
 * For detailed description of this class see the Java language documentation.
 */
final public class Integer extends Number
{
    private int value;
    final public static int MIN_VALUE = 0x80000000;
    final public static int MAX_VALUE = 0x7fffffff;

    public Integer(String s) throws NumberFormatException
    {
        this(parseInt(s));
    }

    public Integer(int value)
    {
        this.value = value;
    }

    public static Integer decode(String nm) throws NumberFormatException
    {
        // Strip off negative sign, if any
        int sign = 1;
        if (nm.startsWith("-"))
        {
            sign = -1;
            nm = nm.substring(1);
        }
        // Strip off base indicator, if any
        int base = 10;
        if (nm.startsWith("0x"))
        {
            base = 16;
            nm = nm.substring(2);
        }
        else if (nm.startsWith("#"))
        {
            base = 16;
            nm = nm.substring(1);
        }
        else if (nm.startsWith("0") && nm.length() > 1)
        {
            base = 8;
            nm = nm.substring(1);
        }
        // A string like "0x-1234" must generate an error; disallow it here
        if (nm.startsWith("-"))
        {
            throw new NumberFormatException();
        }
        return new Integer(sign * parseInt(nm, base));
    }

    public boolean equals(Object obj)
    {
        if ((obj!=null) && (obj instanceof Integer))
        {
            return (this.intValue() == ((Integer)obj).intValue());
        }

        return false;
    }

    public float floatValue()
    {
        return (float)value;
    }

    public int hashCode()
    {
        return this.intValue();
    }

    public int intValue()
    {
        return value;
    }

    public static int parseInt(String s) throws NumberFormatException
    {
        return (parseInt(s, 10));
    }

    public static int parseInt(String s, int radix) throws NumberFormatException
    {
        if (s.length()<=0) throw new NumberFormatException();

        // Check for negativity
        if (s.charAt(0)=='-')
        {
            return parseInt(s.substring(1), radix) * -1;
        }

        int result = 0;
        int position;
        for (position=0; position < s.length(); position++)
        {
            int digit=Character.digit(s.charAt(position), radix);
            if (digit == -1)
            {
                throw new NumberFormatException();
            }

            result=(result * radix) + digit;
        }

        return result;
    }

    private static String toUnsignedString(int i, int bits)
    {
        if (i == 0)
        {
            return "0";
        }

        StringBuffer buf = new StringBuffer();
        int radix = 1 << bits, mask = radix - 1;
        while (i != 0)
        {
            char digit = Character.forDigit(i & mask, radix);
            i >>>= bits;
            buf.append(digit);
        }
        buf.reverse();
        return buf.toString();
    }

    public static String toBinaryString(int i)
    {
        return toUnsignedString(i, 1);
    }

    public static String toHexString(int i)
    {
        return toUnsignedString(i, 4);
    }

    public static String toOctalString(int i)
    {
        return toUnsignedString(i, 3);
    }

    public String toString()
    {
        return toString(this.intValue());
    }

    public static String toString(int i)
    {
        return toString(i, 10);
    }

    public static String toString(int i, int radix)
    {
        if (i == 0)
        {
            return "0";
        }

        if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
        {
            radix = 10;
        }

        StringBuffer buf = new StringBuffer();
        int sign = 1;
        if (i < 0)
        {
            sign = -1;
        }
        while (i != 0)
        {
            char digit = Character.forDigit(Math.abs(i % radix), radix);
            i = i / radix;
            buf.append(digit);
        }
        if (sign == -1)
        {
            buf.append('-');
        }
        buf.reverse();
        return (buf.toString());
    }

    public static Integer valueOf(String s) throws NumberFormatException
    {
        return valueOf(s, 10);
    }

    public static Integer valueOf(String s, int radix) throws NumberFormatException
    {
        return new Integer(parseInt(s, radix));
    }
}