hashcodeutils.java

主要是对串口驱动的的一些控制源码！！！ 在下载javacomm20-win32.zip后就可以使用。

// Copyright <applicate>, 2002. All Rights Reserved.
// This software is the proprietary information of www.applicate.de.
// Use is subject to license terms.

package de.applicate.util.lang;



/**
 * See JavaSpektrum 5/6/2002 page 64 and Joshua Bloch "Effective Java" page 38
 *
 * @author     hs
 * @created    11. Juni 2002
 * @version    $Author: mwulff $ checked in $Revision: 1.1 $ at $Date: 2003/01/16 13:04:46 $
 */
public abstract class HashCodeUtils {
    private final static  int[]  INTNULLNULL  = new int[]{0, 0};


    private HashCodeUtils() {
    }


    public static int getFieldHashCode(boolean _bValue) {
        return _bValue ? 0 : 1;
    }


    public static int getFieldHashCode(byte _byteValue) {
        return (int)_byteValue;
    }


    public static int getFieldHashCode(char _charValue) {
        return (int)_charValue;
    }


    public static int getFieldHashCode(short _shortValue) {
        return (int)_shortValue;
    }


    public static int getFieldHashCode(int _nValue) {
        return _nValue;
    }


    public static int getFieldHashCode(long _lValue) {
        return (int)(_lValue ^ (_lValue >>> 32));
    }


    public static int[] getFieldHashCodes(long _lValue) {
        return new int[]{(int)(_lValue >>> 32), (int)(_lValue & 0xFFFFFFFF)};
    }


    public static int getFieldHashCode(float _fValue) {
        return (_fValue == 0.0F) ? 0 : Float.floatToIntBits(_fValue);
    }


    public static int getFieldHashCode(double _dValue) {
        return (_dValue == 0.0) ? 0 : getFieldHashCode(Double.doubleToLongBits(_dValue));
    }


    public static int[] getFieldHashCodes(double _dValue) {
        return (_dValue == 0.0) ? INTNULLNULL : getFieldHashCodes(Double.doubleToLongBits(_dValue));
    }


    public static int getFieldHashCode(Object _oValue) {
        return (_oValue == null) ? 0 : _oValue.hashCode();
    }


    /**
     * Determins hash code if super class is a class without calculated hash code (Object).
     *
     * @param  _nHashCodesOfFields
     * @return
     */
    public static int getHashCode(final int[] _nHashCodesOfFields) {
        return getHashCode(_nHashCodesOfFields, 0);
    }


    /**
     * <code>HashCodeUtils.getHashCode(nHashCodeFields, super.hashCode()</code>
     *
     * @param  _nHashCodesOfFields
     * @param  _nHashCodeSuperClass  0 if super class is Object
     * @return
     */
    public static int getHashCode(final int[] _nHashCodesOfFields, int _nHashCodeSuperClass) {
        int  nResult  = (0 == _nHashCodeSuperClass) ? 17 : _nHashCodeSuperClass;
        for (int i = 0; i < _nHashCodesOfFields.length; i++) {
            nResult = 37 * nResult + _nHashCodesOfFields[i];
        }
        return nResult;
    }


    /**
     * Determins hash code if super class is a class without calculated hash code (Object).
     *
     * @param  _nHashCodesOfField
     * @return
     */
    public static int getHashCode(final int _nHashCodesOfField) {
        return getHashCode(_nHashCodesOfField, 0);
    }


    /**
     * <code>HashCodeUtils.getHashCode(nHashCodeField, super.hashCode()</code>
     *
     * @param  _nHashCodesOfField
     * @param  _nHashCodeSuperClass  0 if super class is Object
     * @return
     */
    public static int getHashCode(final int _nHashCodesOfField, int _nHashCodeSuperClass) {
        int  nResult  = (0 == _nHashCodeSuperClass) ? 17 : _nHashCodeSuperClass;
        return 37 * nResult + _nHashCodesOfField;
    }

}