| /* ==================================================================== |
| 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.poi.poifs.storage; |
| |
| import java.io.IOException; |
| |
| /** |
| * A simple implementation of BlockList |
| * |
| * @author Marc Johnson (mjohnson at apache dot org |
| */ |
| abstract class BlockListImpl implements BlockList { |
| private ListManagedBlock[] _blocks; |
| private BlockAllocationTableReader _bat; |
| |
| protected BlockListImpl() |
| { |
| _blocks = new ListManagedBlock[ 0 ]; |
| _bat = null; |
| } |
| |
| /** |
| * provide blocks to manage |
| * |
| * @param blocks blocks to be managed |
| */ |
| protected void setBlocks(final ListManagedBlock [] blocks) |
| { |
| _blocks = blocks; |
| } |
| |
| /** |
| * remove the specified block from the list |
| * |
| * @param index the index of the specified block; if the index is |
| * out of range, that's ok |
| */ |
| public void zap(final int index) |
| { |
| if ((index >= 0) && (index < _blocks.length)) |
| { |
| _blocks[ index ] = null; |
| } |
| } |
| |
| /** |
| * Unit testing method. Gets, without sanity checks or |
| * removing. |
| */ |
| protected ListManagedBlock get(final int index) { |
| return _blocks[index]; |
| } |
| |
| /** |
| * remove and return the specified block from the list |
| * |
| * @param index the index of the specified block |
| * |
| * @return the specified block |
| * |
| * @exception IOException if the index is out of range or has |
| * already been removed |
| */ |
| public ListManagedBlock remove(final int index) |
| throws IOException |
| { |
| ListManagedBlock result = null; |
| |
| try |
| { |
| result = _blocks[ index ]; |
| if (result == null) |
| { |
| throw new IOException( |
| "block[ " + index + " ] already removed - " + |
| "does your POIFS have circular or duplicate block references?" |
| ); |
| } |
| _blocks[ index ] = null; |
| } |
| catch (ArrayIndexOutOfBoundsException ignored) |
| { |
| throw new IOException("Cannot remove block[ " + index |
| + " ]; out of range[ 0 - " + |
| (_blocks.length-1) + " ]"); |
| } |
| return result; |
| } |
| |
| /** |
| * get the blocks making up a particular stream in the list. The |
| * blocks are removed from the list. |
| * |
| * @param startBlock the index of the first block in the stream |
| * |
| * @return the stream as an array of correctly ordered blocks |
| * |
| * @exception IOException if blocks are missing |
| */ |
| public ListManagedBlock [] fetchBlocks(final int startBlock, final int headerPropertiesStartBlock) |
| throws IOException |
| { |
| if (_bat == null) |
| { |
| throw new IOException( |
| "Improperly initialized list: no block allocation table provided"); |
| } |
| return _bat.fetchBlocks(startBlock, headerPropertiesStartBlock, this); |
| } |
| |
| /** |
| * set the associated BlockAllocationTable |
| * |
| * @param bat the associated BlockAllocationTable |
| */ |
| public void setBAT(final BlockAllocationTableReader bat) |
| throws IOException |
| { |
| if (_bat != null) |
| { |
| throw new IOException( |
| "Attempt to replace existing BlockAllocationTable"); |
| } |
| _bat = bat; |
| } |
| |
| /** |
| * Returns the count of the number of blocks |
| */ |
| public int blockCount() { |
| return _blocks.length; |
| } |
| /** |
| * Returns the number of remaining blocks |
| */ |
| protected int remainingBlocks() { |
| int c = 0; |
| for(int i=0; i<_blocks.length; i++) { |
| if(_blocks[i] != null) c++; |
| } |
| return c; |
| } |
| } |