Move main source to src/main/java

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/lang/trunk@895322 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 290 insertions, 0 deletions

diff --git a/src/main/java/org/apache/commons/lang3/BitField.java b/src/main/java/org/apache/commons/lang3/BitField.java
new file mode 100644
index 000000000..b6e513c68
--- /dev/null
+++ b/src/main/java/org/apache/commons/lang3/BitField.java
@@ -0,0 +1,290 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.lang3;
+
+/**
+ * <p>Operations on bit-mapped fields.</p>
+ *
+ * @author Apache Software Foundation
+ * @author Apache Jakarta POI
+ * @author Scott Sanders (sanders at apache dot org)
+ * @author Marc Johnson (mjohnson at apache dot org)
+ * @author Andrew C. Oliver (acoliver at apache dot org)
+ * @author Pete Gieser
+ * @author Gary Gregory
+ * @since 2.0
+ * @version $Id$
+ */
+public class BitField {
+    
+    private final int _mask;
+    private final int _shift_count;
+
+    /**
+     * <p>Creates a BitField instance.</p>
+     *
+     * @param mask the mask specifying which bits apply to this
+     *  BitField. Bits that are set in this mask are the bits
+     *  that this BitField operates on
+     */
+    public BitField(int mask) {
+        _mask = mask;
+        int count = 0;
+        int bit_pattern = mask;
+
+        if (bit_pattern != 0) {
+            while ((bit_pattern & 1) == 0) {
+                count++;
+                bit_pattern >>= 1;
+            }
+        }
+        _shift_count = count;
+    }
+
+    /**
+     * <p>Obtains the value for the specified BitField, appropriately
+     * shifted right.</p>
+     *
+     * <p>Many users of a BitField will want to treat the specified
+     * bits as an int value, and will not want to be aware that the
+     * value is stored as a BitField (and so shifted left so many
+     * bits).</p>
+     *
+     * @see #setValue(int,int)
+     * @param holder the int data containing the bits we're interested
+     *  in
+     * @return the selected bits, shifted right appropriately
+     */
+    public int getValue(int holder) {
+        return getRawValue(holder) >> _shift_count;
+    }
+
+    /**
+     * <p>Obtains the value for the specified BitField, appropriately
+     * shifted right, as a short.</p>
+     *
+     * <p>Many users of a BitField will want to treat the specified
+     * bits as an int value, and will not want to be aware that the
+     * value is stored as a BitField (and so shifted left so many
+     * bits).</p>
+     *
+     * @see #setShortValue(short,short)
+     * @param holder the short data containing the bits we're
+     *  interested in
+     * @return the selected bits, shifted right appropriately
+     */
+    public short getShortValue(short holder) {
+        return (short) getValue(holder);
+    }
+
+    /**
+     * <p>Obtains the value for the specified BitField, unshifted.</p>
+     *
+     * @param holder the int data containing the bits we're
+     *  interested in
+     * @return the selected bits
+     */
+    public int getRawValue(int holder) {
+        return holder & _mask;
+    }
+
+    /**
+     * <p>Obtains the value for the specified BitField, unshifted.</p>
+     *
+     * @param holder the short data containing the bits we're
+     *  interested in
+     * @return the selected bits
+     */
+    public short getShortRawValue(short holder) {
+        return (short) getRawValue(holder);
+    }
+
+    /**
+     * <p>Returns whether the field is set or not.</p>
+     *
+     * <p>This is most commonly used for a single-bit field, which is
+     * often used to represent a boolean value; the results of using
+     * it for a multi-bit field is to determine whether *any* of its
+     * bits are set.</p>
+     *
+     * @param holder the int data containing the bits we're interested
+     *  in
+     * @return <code>true</code> if any of the bits are set,
+     *  else <code>false</code>
+     */
+    public boolean isSet(int holder) {
+        return (holder & _mask) != 0;
+    }
+
+    /**
+     * <p>Returns whether all of the bits are set or not.</p>
+     *
+     * <p>This is a stricter test than {@link #isSet(int)},
+     * in that all of the bits in a multi-bit set must be set
+     * for this method to return <code>true</code>.</p>
+     *
+     * @param holder the int data containing the bits we're
+     *  interested in
+     * @return <code>true</code> if all of the bits are set,
+     *  else <code>false</code>
+     */
+    public boolean isAllSet(int holder) {
+        return (holder & _mask) == _mask;
+    }
+
+    /**
+     * <p>Replaces the bits with new values.</p>
+     *
+     * @see #getValue(int)
+     * @param holder the int data containing the bits we're
+     *  interested in
+     * @param value the new value for the specified bits
+     * @return the value of holder with the bits from the value
+     *  parameter replacing the old bits
+     */
+    public int setValue(int holder, int value) {
+        return (holder & ~_mask) | ((value << _shift_count) & _mask);
+    }
+
+    /**
+     * <p>Replaces the bits with new values.</p>
+     *
+     * @see #getShortValue(short)
+     * @param holder the short data containing the bits we're
+     *  interested in
+     * @param value the new value for the specified bits
+     * @return the value of holder with the bits from the value
+     *  parameter replacing the old bits
+     */
+    public short setShortValue(short holder, short value) {
+        return (short) setValue(holder, value);
+    }
+
+    /**
+     * <p>Clears the bits.</p>
+     *
+     * @param holder the int data containing the bits we're
+     *  interested in
+     * @return the value of holder with the specified bits cleared
+     *  (set to <code>0</code>)
+     */
+    public int clear(int holder) {
+        return holder & ~_mask;
+    }
+
+    /**
+     * <p>Clears the bits.</p>
+     *
+     * @param holder the short data containing the bits we're
+     *  interested in
+     * @return the value of holder with the specified bits cleared
+     *  (set to <code>0</code>)
+     */
+    public short clearShort(short holder) {
+        return (short) clear(holder);
+    }
+
+    /**
+     * <p>Clears the bits.</p>
+     *
+     * @param holder the byte data containing the bits we're
+     *  interested in
+     *
+     * @return the value of holder with the specified bits cleared
+     *  (set to <code>0</code>)
+     */
+    public byte clearByte(byte holder) {
+        return (byte) clear(holder);
+    }
+
+    /**
+     * <p>Sets the bits.</p>
+     *
+     * @param holder the int data containing the bits we're
+     *  interested in
+     * @return the value of holder with the specified bits set
+     *  to <code>1</code>
+     */
+    public int set(int holder) {
+        return holder | _mask;
+    }
+
+    /**
+     * <p>Sets the bits.</p>
+     *
+     * @param holder the short data containing the bits we're
+     *  interested in
+     * @return the value of holder with the specified bits set
+     *  to <code>1</code>
+     */
+    public short setShort(short holder) {
+        return (short) set(holder);
+    }
+
+    /**
+     * <p>Sets the bits.</p>
+     *
+     * @param holder the byte data containing the bits we're
+     *  interested in
+     *
+     * @return the value of holder with the specified bits set
+     *  to <code>1</code>
+     */
+    public byte setByte(byte holder) {
+        return (byte) set(holder);
+    }
+
+    /**
+     * <p>Sets a boolean BitField.</p>
+     *
+     * @param holder the int data containing the bits we're
+     *  interested in
+     * @param flag indicating whether to set or clear the bits
+     * @return the value of holder with the specified bits set or
+     *         cleared
+     */
+    public int setBoolean(int holder, boolean flag) {
+        return flag ? set(holder) : clear(holder);
+    }
+
+    /**
+     * <p>Sets a boolean BitField.</p>
+     *
+     * @param holder the short data containing the bits we're
+     *  interested in
+     * @param flag indicating whether to set or clear the bits
+     * @return the value of holder with the specified bits set or
+     *  cleared
+     */
+    public short setShortBoolean(short holder, boolean flag) {
+        return flag ? setShort(holder) : clearShort(holder);
+    }
+
+    /**
+     * <p>Sets a boolean BitField.</p>
+     *
+     * @param holder the byte data containing the bits we're
+     *  interested in
+     * @param flag indicating whether to set or clear the bits
+     * @return the value of holder with the specified bits set or
+     *  cleared
+     */
+    public byte setByteBoolean(byte holder, boolean flag) {
+        return flag ? setByte(holder) : clearByte(holder);
+    }
+
+}