hashcodebuilder.java

可用于文本分类的贝叶斯分类器

     * given <code>Class</code>.</p>
     * 
     * @param object  the object to append details of
     * @param clazz  the class to append details of
     * @param builder  the builder to append to
     * @param useTransients  whether to use transient fields
     */
    private static void reflectionAppend(Object object, Class clazz, HashCodeBuilder builder, boolean useTransients) {
        Field[] fields = clazz.getDeclaredFields();
        AccessibleObject.setAccessible(fields, true);
        for (int i = 0; i < fields.length; i++) {
            Field f = fields[i];
            if ((f.getName().indexOf('$') == -1)
                && (useTransients || !Modifier.isTransient(f.getModifiers()))
                && (!Modifier.isStatic(f.getModifiers()))) {
                try {
                    builder.append(f.get(object));
                } catch (IllegalAccessException e) {
                    //this can't happen. Would get a Security exception instead
                    //throw a runtime exception in case the impossible happens.
                    throw new InternalError("Unexpected IllegalAccessException");
                }
            }
        }
    }

    //-------------------------------------------------------------------------

    /**
     * <p>Adds the result of super.hashCode() to this builder.</p>
     *
     * @param superHashCode  the result of calling <code>super.hashCode()</code>
     * @return this HashCodeBuilder, used to chain calls.
     * @since 2.0
     */
    public HashCodeBuilder appendSuper(int superHashCode) {
        iTotal = iTotal * iConstant + superHashCode;
        return this;
    }

    //-------------------------------------------------------------------------

    /**
     * <p>Append a <code>hashCode</code> for an <code>Object</code>.</p>
     *
     * @param object  the Object to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(Object object) {
        if (object == null) {
            iTotal = iTotal * iConstant;

        } else {
            if (object.getClass().isArray() == false) {
                //the simple case, not an array, just the element
                iTotal = iTotal * iConstant + object.hashCode();

            } else {
                //'Switch' on type of array, to dispatch to the correct handler
                // This handles multi dimensional arrays
                if (object instanceof long[]) {
                    append((long[]) object);
                } else if (object instanceof int[]) {
                    append((int[]) object);
                } else if (object instanceof short[]) {
                    append((short[]) object);
                } else if (object instanceof char[]) {
                    append((char[]) object);
                } else if (object instanceof byte[]) {
                    append((byte[]) object);
                } else if (object instanceof double[]) {
                    append((double[]) object);
                } else if (object instanceof float[]) {
                    append((float[]) object);
                } else if (object instanceof boolean[]) {
                    append((boolean[]) object);
                } else {
                    // Not an array of primitives
                    append((Object[]) object);
                }
            }
        }
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>long</code>.</p>
     *
     * @param value  the long to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(long value) {
        iTotal = iTotal * iConstant + ((int) (value ^ (value >> 32)));
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for an <code>int</code>.</p>
     *
     * @param value  the int to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(int value) {
        iTotal = iTotal * iConstant + value;
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>short</code>.</p>
     *
     * @param value  the short to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(short value) {
        iTotal = iTotal * iConstant + value;
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>char</code>.</p>
     *
     * @param value  the char to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(char value) {
        iTotal = iTotal * iConstant + value;
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>byte</code>.</p>
     *
     * @param value  the byte to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(byte value) {
        iTotal = iTotal * iConstant + value;
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>double</code>.</p>
     *
     * @param value  the double to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(double value) {
        return append(Double.doubleToLongBits(value));
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>float</code>.</p>
     *
     * @param value  the float to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(float value) {
        iTotal = iTotal * iConstant + Float.floatToIntBits(value);
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>boolean</code>.</p>
     *
     * @param value  the boolean to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(boolean value) {
        iTotal = iTotal * iConstant + (value ? 0 : 1);
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for an <code>Object</code> array.</p>
     *
     * @param array  the array to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(Object[] array) {
        if (array == null) {
            iTotal = iTotal * iConstant;
        } else {
            for (int i = 0; i < array.length; i++) {
                append(array[i]);
            }
        }
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>long</code> array.</p>
     *
     * @param array  the array to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(long[] array) {
        if (array == null) {
            iTotal = iTotal * iConstant;
        } else {
            for (int i = 0; i < array.length; i++) {
                append(array[i]);
            }
        }
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for an <code>int</code> array.</p>
     *
     * @param array  the array to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(int[] array) {
        if (array == null) {
            iTotal = iTotal * iConstant;
        } else {
            for (int i = 0; i < array.length; i++) {
                append(array[i]);
            }
        }
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>short</code> array.</p>
     *
     * @param array  the array to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(short[] array) {
        if (array == null) {
            iTotal = iTotal * iConstant;
        } else {
            for (int i = 0; i < array.length; i++) {
                append(array[i]);
            }
        }
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>char</code> array.</p>
     *
     * @param array  the array to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(char[] array) {
        if (array == null) {
            iTotal = iTotal * iConstant;
        } else {
            for (int i = 0; i < array.length; i++) {
                append(array[i]);
            }
        }
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>byte</code> array.</p>
     *
     * @param array  the array to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(byte[] array) {
        if (array == null) {
            iTotal = iTotal * iConstant;
        } else {
            for (int i = 0; i < array.length; i++) {
                append(array[i]);
            }
        }
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>double</code> array.</p>
     *
     * @param array  the array to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(double[] array) {
        if (array == null) {
            iTotal = iTotal * iConstant;
        } else {
            for (int i = 0; i < array.length; i++) {
                append(array[i]);
            }
        }
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>float</code> array.</p>
     *
     * @param array  the array to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(float[] array) {
        if (array == null) {
            iTotal = iTotal * iConstant;
        } else {
            for (int i = 0; i < array.length; i++) {
                append(array[i]);
            }
        }
        return this;
    }

    /**
     * <p>Append a <code>hashCode</code> for a <code>boolean</code> array.</p>
     *
     * @param array  the array to add to the <code>hashCode</code>
     * @return this
     */
    public HashCodeBuilder append(boolean[] array) {
        if (array == null) {
            iTotal = iTotal * iConstant;
        } else {
            for (int i = 0; i < array.length; i++) {
                append(array[i]);
            }
        }
        return this;
    }

    /**
     * <p>Return the computed <code>hashCode</code>.</p>
     *
     * @return <code>hashCode</code> based on the fields appended
     */
    public int toHashCode() {
        return iTotal;
    }

}