1*04ea5bd4SAndrew Rist /************************************************************** 2cdf0e10cSrcweir * 3*04ea5bd4SAndrew Rist * Licensed to the Apache Software Foundation (ASF) under one 4*04ea5bd4SAndrew Rist * or more contributor license agreements. See the NOTICE file 5*04ea5bd4SAndrew Rist * distributed with this work for additional information 6*04ea5bd4SAndrew Rist * regarding copyright ownership. The ASF licenses this file 7*04ea5bd4SAndrew Rist * to you under the Apache License, Version 2.0 (the 8*04ea5bd4SAndrew Rist * "License"); you may not use this file except in compliance 9*04ea5bd4SAndrew Rist * with the License. You may obtain a copy of the License at 10*04ea5bd4SAndrew Rist * 11*04ea5bd4SAndrew Rist * http://www.apache.org/licenses/LICENSE-2.0 12*04ea5bd4SAndrew Rist * 13*04ea5bd4SAndrew Rist * Unless required by applicable law or agreed to in writing, 14*04ea5bd4SAndrew Rist * software distributed under the License is distributed on an 15*04ea5bd4SAndrew Rist * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16*04ea5bd4SAndrew Rist * KIND, either express or implied. See the License for the 17*04ea5bd4SAndrew Rist * specific language governing permissions and limitations 18*04ea5bd4SAndrew Rist * under the License. 19*04ea5bd4SAndrew Rist * 20*04ea5bd4SAndrew Rist *************************************************************/ 21*04ea5bd4SAndrew Rist 22*04ea5bd4SAndrew Rist 23cdf0e10cSrcweir 24cdf0e10cSrcweir 25cdf0e10cSrcweir import java.io.RandomAccessFile; 26cdf0e10cSrcweir import java.io.IOException; 27cdf0e10cSrcweir 28cdf0e10cSrcweir 29cdf0e10cSrcweir /** 30cdf0e10cSrcweir * <p>Provides functionality to decode a pdb formatted file into 31cdf0e10cSrcweir * a <code>PalmDB</code> object given a file input stream</p> 32cdf0e10cSrcweir * 33cdf0e10cSrcweir * <p>Sample usage:</p> 34cdf0e10cSrcweir * 35cdf0e10cSrcweir * <p><blockquote><pre> 36cdf0e10cSrcweir * PDBDecoder decoder = new PDBDecoder("sample.pdb"); 37cdf0e10cSrcweir * PalmDB palmDB = decoder.parse(); 38cdf0e10cSrcweir * </pre></blockquote></p> 39cdf0e10cSrcweir * 40cdf0e10cSrcweir * <p>Refer to the 41cdf0e10cSrcweir * <a href="http://starlite.eng/zensync/eng/converters/palmfileformats.pdf"> 42cdf0e10cSrcweir * Palm file format specification</a> for details on the pdb format.</p> 43cdf0e10cSrcweir * 44cdf0e10cSrcweir * <p>This decoder has the following assumptions on the pdb file ...</p> 45cdf0e10cSrcweir * <ol> 46cdf0e10cSrcweir * <li><p>There is only one RecordList section in the pdb.</p></li> 47cdf0e10cSrcweir * <li><p>The record indices in the RecordList are sorted in order, i.e. the 48cdf0e10cSrcweir * first record index refers to record 0, and so forth.</p></li> 49cdf0e10cSrcweir * <li><p>The raw records in the record section are sorted as well in order, 50cdf0e10cSrcweir * i.e. first record comes ahead of second record, etc.</p></li> 51cdf0e10cSrcweir * </ol> 52cdf0e10cSrcweir * 53cdf0e10cSrcweir * Other decoders assume these as well. 54cdf0e10cSrcweir * 55cdf0e10cSrcweir * @author Herbie Ong 56cdf0e10cSrcweir * @see PalmDB 57cdf0e10cSrcweir * @see PDBHeader 58cdf0e10cSrcweir * 59cdf0e10cSrcweir * @author Herbie Ong 60cdf0e10cSrcweir */ 61cdf0e10cSrcweir 62cdf0e10cSrcweir public final class PDBDecoder { 63cdf0e10cSrcweir 64cdf0e10cSrcweir /** 65cdf0e10cSrcweir * <p>This method decodes a pdb file into a PalmDB object.</p> 66cdf0e10cSrcweir * 67cdf0e10cSrcweir * <p>First, read in the header data using <code>PDBHeader</code>'s 68cdf0e10cSrcweir * <code>read</code> method</p>. Next, read in the record list 69cdf0e10cSrcweir * section. Store the record offsets for use when parsing the records. 70cdf0e10cSrcweir * Based on these offsets, read in each record's bytes and store 71cdf0e10cSrcweir * each in a <code>Record</code> object. Lastly, create a 72cdf0e10cSrcweir * <code>PalmDB</code> object with the read in <code>Record</code>s. 73cdf0e10cSrcweir * 74cdf0e10cSrcweir * @param fileName pdb file name 75cdf0e10cSrcweir * @throws IOException if I/O error occurs 76cdf0e10cSrcweir */ 77cdf0e10cSrcweir parse(String fileName)78cdf0e10cSrcweir public PalmDB parse(String fileName) throws IOException { 79cdf0e10cSrcweir 80cdf0e10cSrcweir RandomAccessFile file = new RandomAccessFile(fileName, "r"); 81cdf0e10cSrcweir 82cdf0e10cSrcweir // read the pdb header 83cdf0e10cSrcweir PDBHeader header = new PDBHeader(); 84cdf0e10cSrcweir header.read(file); 85cdf0e10cSrcweir 86cdf0e10cSrcweir Record recArray[] = new Record[header.numRecords]; 87cdf0e10cSrcweir 88cdf0e10cSrcweir if (header.numRecords != 0) { 89cdf0e10cSrcweir 90cdf0e10cSrcweir // read in the record indices + offsets 91cdf0e10cSrcweir 92cdf0e10cSrcweir int recOffset[] = new int[header.numRecords]; 93cdf0e10cSrcweir 94cdf0e10cSrcweir for (int i = 0; i < header.numRecords; i++) { 95cdf0e10cSrcweir 96cdf0e10cSrcweir recOffset[i] = file.readInt(); 97cdf0e10cSrcweir int attr = file.readInt(); // read in attribute. 98cdf0e10cSrcweir } 99cdf0e10cSrcweir 100cdf0e10cSrcweir // read the records 101cdf0e10cSrcweir 102cdf0e10cSrcweir int len = 0; 103cdf0e10cSrcweir byte[] bytes = null; 104cdf0e10cSrcweir 105cdf0e10cSrcweir int lastIndex = header.numRecords - 1; 106cdf0e10cSrcweir 107cdf0e10cSrcweir for (int i = 0; i < lastIndex; i++) { 108cdf0e10cSrcweir 109cdf0e10cSrcweir file.seek(recOffset[i]); 110cdf0e10cSrcweir len = recOffset[i+1] - recOffset[i]; 111cdf0e10cSrcweir bytes = new byte[len]; 112cdf0e10cSrcweir file.readFully(bytes); 113cdf0e10cSrcweir recArray[i] = new Record(bytes); 114cdf0e10cSrcweir } 115cdf0e10cSrcweir 116cdf0e10cSrcweir // last record 117cdf0e10cSrcweir file.seek(recOffset[lastIndex]); 118cdf0e10cSrcweir len = (int) file.length() - recOffset[lastIndex]; 119cdf0e10cSrcweir bytes = new byte[len]; 120cdf0e10cSrcweir file.readFully(bytes); 121cdf0e10cSrcweir recArray[lastIndex] = new Record(bytes); 122cdf0e10cSrcweir } 123cdf0e10cSrcweir 124cdf0e10cSrcweir file.close(); 125cdf0e10cSrcweir 126cdf0e10cSrcweir // create PalmDB and return it 127cdf0e10cSrcweir PalmDB pdb = new PalmDB(header.pdbName, recArray); 128cdf0e10cSrcweir return pdb; 129cdf0e10cSrcweir } 130cdf0e10cSrcweir } 131cdf0e10cSrcweir 132