Here you can find the source of read_structdesc(final RandomAccessFile raf)
public static HashMap<String, Object> read_structdesc(final RandomAccessFile raf) throws IOException, Exception
//package com.java2s; /******************************************************************************* * Copyright 2016 CNES - CENTRE NATIONAL d'ETUDES SPATIALES * * This file is part of JSave.//from w ww .j a va 2s. co m * * JSave is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * JSave is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with JSave. If not, see <http://www.gnu.org/licenses/>. ******************************************************************************/ import java.io.IOException; import java.io.RandomAccessFile; import java.math.BigInteger; import java.nio.ByteBuffer; import java.nio.charset.StandardCharsets; import java.util.HashMap; public class Main { public static final HashMap STRUCT_DICT = new HashMap(); private static final HashMap<Integer, String> DTYPE_DICT = new HashMap<Integer, String>() { { put(1, ">u1"); //1-byte unsigned integer, "U1 0" put(2, ">i2"); //2-byte signed integer, "I2 99", "I2 15 -7 99" put(3, ">i4"); //4-byte integer signed, "I4 -5" put(4, ">f4"); //4-byte floating point, "F4 1.0" put(5, ">f8"); //8-byte floating point, "F8 6.02e23", "F8 0.1" put(6, ">c8"); put(7, "|O"); put(8, "|O"); put(9, ">c16"); //128-bit complex floating-point number put(10, "|O"); put(11, "|O"); put(12, ">u2"); //2-byte unsigned integer, "U2 512" put(13, ">u4"); //4-byte unsigned integer, "U2 979" put(14, ">i8"); //8-byte signed integer, use hex notation for the value, "I8 0x123456789abcdf01" put(15, ">u8"); //8-byte unsigned integer, use hex notation for the value, "U8 0x7fffffffffffffff" } }; public static HashMap<String, Object> read_structdesc(final RandomAccessFile raf) throws IOException, Exception { HashMap<String, Object> structdesc = new HashMap<>(); int structstart = read_long(raf); if (structstart != 9) { throw new Exception("STRUCTSTART should be 9"); } structdesc.put("name", read_string(raf)); int predef = read_long(raf); structdesc.put("ntags", read_long(raf)); structdesc.put("nbytes", read_long(raf)); structdesc.put("predef", predef & 1); structdesc.put("inherits", predef & 2); structdesc.put("is_super", predef & 4); if ((int) structdesc.get("predef") != 1) { int length = (int) structdesc.get("ntags"); HashMap[] tagtable = new HashMap[length]; String[] name = new String[length]; for (int i = 0; i < length; i++) { tagtable[i] = read_tagdesc(raf); } structdesc.put("tagtable", tagtable); for (HashMap tag : (HashMap[]) structdesc.get("tagtable")) { tag.put("name", read_string(raf)); } HashMap<String, Object> arrtable = new HashMap<>(); for (HashMap tag : (HashMap[]) structdesc.get("tagtable")) { if ((int) tag.get("array") == 1) { arrtable.put((String) tag.get("name"), read_arraydesc(raf)); } } structdesc.put("arrtable", arrtable); HashMap<String, Object> structtable = new HashMap<>(); for (HashMap tag : (HashMap[]) structdesc.get("tagtable")) { if ((int) tag.get("structure") == 1) { structtable.put((String) tag.get("name"), read_structdesc(raf)); } } structdesc.put("structtable", structtable); if ((int) structdesc.get("inherits") == 1 || (int) structdesc.get("is_super") == 1) { structdesc.put("classname", read_string(raf)); structdesc.put("nsupclasses", read_long(raf)); int lengthSupclassnames = (int) structdesc.get("nsupclasses"); String[] supclassnames = new String[lengthSupclassnames]; for (int i = 0; i < lengthSupclassnames; i++) { supclassnames[i] = read_string(raf); } structdesc.put("supclassnames", supclassnames); HashMap[] supclasstable = new HashMap[((HashMap[]) structdesc.get("nsupclasses")).length]; for (int i = 0; i < ((HashMap[]) structdesc.get("nsupclasses")).length; i++) { supclasstable[i] = read_structdesc(raf); } structdesc.put("supclasstable", supclasstable); } STRUCT_DICT.put(structdesc.get("name"), structdesc); } else { if (!STRUCT_DICT.containsKey(structdesc.get("name"))) { throw new Exception("PREDEF=1 but can't find definition"); } structdesc = (HashMap<String, Object>) STRUCT_DICT.get(structdesc.get("name")); } return structdesc; } public static int read_long(final RandomAccessFile raf) throws IOException { byte[] data = new byte[4]; raf.read(data); ByteBuffer bb = ByteBuffer.allocate(data.length); bb.put(data); return bb.getInt(0); } public static String read_string(final RandomAccessFile raf) throws IOException { int length = read_long(raf); String result; if (length > 0) { byte[] data = new byte[length]; raf.read(data); align_32(raf); result = new String(data, StandardCharsets.UTF_8); } else { result = ""; } return result; } private static HashMap<String, Object> read_tagdesc(RandomAccessFile raf) throws IOException { HashMap<String, Object> tagdesc = new HashMap<>(); tagdesc.put("offset", read_long(raf)); if ((int) tagdesc.get("offset") == -1) { tagdesc.put("offset", read_uint64(raf)); } tagdesc.put("typecode", read_long(raf)); int tagflags = read_long(raf); tagdesc.put("array", (tagflags & 4) == 4); tagdesc.put("structure", (tagflags & 32) == 32); tagdesc.put("scalar", DTYPE_DICT.containsKey(tagdesc.get("typecode"))); // Assume '10'x is scalar return tagdesc; } public static HashMap<String, Object> read_arraydesc(final RandomAccessFile raf) throws IOException, Exception { HashMap<String, Object> arraydesc = new HashMap<>(); arraydesc.put("arrstart", read_long(raf)); int arrStart = (int) arraydesc.get("arrstart"); switch (arrStart) { case 8: skip_bytes(raf, 4); arraydesc.put("nbytes", read_long(raf)); arraydesc.put("nelements", read_long(raf)); arraydesc.put("ndims", read_long(raf)); skip_bytes(raf, 8); arraydesc.put("nmax", read_long(raf)); int length = (int) arraydesc.get("nmax"); int[] dims = new int[length]; for (int i = 0; i < length; i++) { dims[i] = read_long(raf); } arraydesc.put("dims", dims); break; case 18: throw new UnsupportedOperationException("arrstart=18 is not supported"); //warnings.warn("Using experimental 64-bit array read") //_skip_bytes(f, 8) //arraydesc['nbytes'] = _read_uint64(f) //arraydesc['nelements'] = _read_uint64(f) //arraydesc['ndims'] = _read_long(f) //_skip_bytes(f, 8) //arraydesc['nmax'] = 8 //arraydesc['dims'] = [] //for d in range(arraydesc['nmax']): // v = _read_long(f) // if v != 0: // raise Exception("Expected a zero in ARRAY_DESC") // arraydesc['dims'].append(_read_long(f)) //break; default: throw new Exception("Unknown ARRSTART: " + arraydesc.get("arrstart")); } return arraydesc; } public static final void align_32(RandomAccessFile raf) throws IOException { long pos = raf.getFilePointer(); if (pos % 4 != 0) { raf.seek(pos + 4 - pos % 4); } } private static BigInteger read_uint64(final RandomAccessFile raf) throws IOException { byte[] data = new byte[8]; raf.read(data); return new BigInteger(1, data); } /** * Skip length bytes. * * @param raf the file where the bytes are read * @param length the length to skip * @throws IOException */ public static void skip_bytes(final RandomAccessFile raf, int length) throws IOException { byte[] data = new byte[length]; raf.read(data); } }