| /************************************************************** |
| * |
| * 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. |
| * |
| *************************************************************/ |
| |
| |
| |
| |
| import java.io.RandomAccessFile; |
| import java.io.IOException; |
| |
| |
| /** |
| * <p>Provides functionality to decode a pdb formatted file into |
| * a <code>PalmDB</code> object given a file input stream</p> |
| * |
| * <p>Sample usage:</p> |
| * |
| * <p><blockquote><pre> |
| * PDBDecoder decoder = new PDBDecoder("sample.pdb"); |
| * PalmDB palmDB = decoder.parse(); |
| * </pre></blockquote></p> |
| * |
| * <p>Refer to the |
| * <a href="http://starlite.eng/zensync/eng/converters/palmfileformats.pdf"> |
| * Palm file format specification</a> for details on the pdb format.</p> |
| * |
| * <p>This decoder has the following assumptions on the pdb file ...</p> |
| * <ol> |
| * <li><p>There is only one RecordList section in the pdb.</p></li> |
| * <li><p>The record indices in the RecordList are sorted in order, i.e. the |
| * first record index refers to record 0, and so forth.</p></li> |
| * <li><p>The raw records in the record section are sorted as well in order, |
| * i.e. first record comes ahead of second record, etc.</p></li> |
| * </ol> |
| * |
| * Other decoders assume these as well. |
| * |
| * @author Herbie Ong |
| * @see PalmDB |
| * @see PDBHeader |
| * |
| * @author Herbie Ong |
| */ |
| |
| public final class PDBDecoder { |
| |
| /** |
| * <p>This method decodes a pdb file into a PalmDB object.</p> |
| * |
| * <p>First, read in the header data using <code>PDBHeader</code>'s |
| * <code>read</code> method</p>. Next, read in the record list |
| * section. Store the record offsets for use when parsing the records. |
| * Based on these offsets, read in each record's bytes and store |
| * each in a <code>Record</code> object. Lastly, create a |
| * <code>PalmDB</code> object with the read in <code>Record</code>s. |
| * |
| * @param fileName pdb file name |
| * @throws IOException if I/O error occurs |
| */ |
| |
| public PalmDB parse(String fileName) throws IOException { |
| |
| RandomAccessFile file = new RandomAccessFile(fileName, "r"); |
| |
| // read the pdb header |
| PDBHeader header = new PDBHeader(); |
| header.read(file); |
| |
| Record recArray[] = new Record[header.numRecords]; |
| |
| if (header.numRecords != 0) { |
| |
| // read in the record indices + offsets |
| |
| int recOffset[] = new int[header.numRecords]; |
| |
| for (int i = 0; i < header.numRecords; i++) { |
| |
| recOffset[i] = file.readInt(); |
| int attr = file.readInt(); // read in attribute. |
| } |
| |
| // read the records |
| |
| int len = 0; |
| byte[] bytes = null; |
| |
| int lastIndex = header.numRecords - 1; |
| |
| for (int i = 0; i < lastIndex; i++) { |
| |
| file.seek(recOffset[i]); |
| len = recOffset[i+1] - recOffset[i]; |
| bytes = new byte[len]; |
| file.readFully(bytes); |
| recArray[i] = new Record(bytes); |
| } |
| |
| // last record |
| file.seek(recOffset[lastIndex]); |
| len = (int) file.length() - recOffset[lastIndex]; |
| bytes = new byte[len]; |
| file.readFully(bytes); |
| recArray[lastIndex] = new Record(bytes); |
| } |
| |
| file.close(); |
| |
| // create PalmDB and return it |
| PalmDB pdb = new PalmDB(header.pdbName, recArray); |
| return pdb; |
| } |
| } |
| |