Java tutorial
/* Copyright (C) 2005-2012, by the President and Fellows of Harvard College. Licensed 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. Dataverse Network - A web application to share, preserve and analyze research data. Developed at the Institute for Quantitative Social Science, Harvard University. Version 3.0. */ package edu.harvard.iq.dvn.ingest.statdataio.impl.plugins.dta; import edu.harvard.iq.dvn.ingest.org.thedata.statdataio.spi.*; import edu.harvard.iq.dvn.ingest.org.thedata.statdataio.*; import java.io.*; import java.nio.*; import java.nio.channels.*; import java.util.logging.*; import javax.imageio.IIOException; import static java.lang.System.*; import java.util.*; import org.apache.commons.codec.binary.Hex; /** * * @author akio sone at UNC-Odum */ public class DTAFileReaderSpi extends StatDataFileReaderSpi { private static Map<Byte, String> stataReleaseNumber = new HashMap<Byte, String>(); static { stataReleaseNumber.put((byte) 104, "rel_3"); stataReleaseNumber.put((byte) 105, "rel_4or5"); stataReleaseNumber.put((byte) 108, "rel_6"); stataReleaseNumber.put((byte) 110, "rel_7first"); stataReleaseNumber.put((byte) 111, "rel_7scnd"); stataReleaseNumber.put((byte) 113, "rel_8_or_9"); stataReleaseNumber.put((byte) 114, "rel_10"); } private static String[] formatNames = { "dta", "DTA" }; private static String[] extensions = { "dta" }; private static String[] mimeType = { "application/x-stata" }; private static Logger dbgLog = Logger.getLogger(DTAFileReaderSpi.class.getPackage().getName()); private static int DTA_HEADER_SIZE = 4; /** * */ public DTAFileReaderSpi() { super("HU-IQSS-DVN-project", "0.1", formatNames, extensions, mimeType, "edu.harvard.hmdc.vdcnet.util.statdataio.plugins.dta.DTAFileReaderSpi"); dbgLog.fine("DTAFileReaderSpi is called"); } /** * Returns the value of the description of the corresponding * DTAFileReader class. * * @param locale * @return the value of the description of the corresponding * DTAFileReader class */ public String getDescription(Locale locale) { return "HU-IQSS-DVN-project Stata File Reader"; } @Override public boolean canDecodeInput(Object source) throws IOException { if (!(source instanceof BufferedInputStream)) { return false; } if (source == null) { throw new IllegalArgumentException("stream == null!"); } BufferedInputStream stream = (BufferedInputStream) source; dbgLog.fine("applying the dta test\n"); byte[] b = new byte[DTA_HEADER_SIZE]; if (stream.markSupported()) { stream.mark(0); } int nbytes = stream.read(b, 0, DTA_HEADER_SIZE); if (nbytes == 0) { throw new IOException(); } //printHexDump(b, "hex dump of the byte-array"); if (stream.markSupported()) { stream.reset(); } dbgLog.info("hex dump: 1st 4bytes =>" + new String(Hex.encodeHex(b)) + "<-"); if (b[2] != 1) { dbgLog.fine("3rd byte is not 1: given file is not stata-dta type"); return false; } else if ((b[1] != 1) && (b[1] != 2)) { dbgLog.fine("2nd byte is neither 0 nor 1: this file is not stata-dta type"); return false; } else if (!DTAFileReaderSpi.stataReleaseNumber.containsKey(b[0])) { dbgLog.fine("1st byte (" + b[0] + ") is not within the ingestable range [rel. 3-10]:" + "this file is NOT stata-dta type"); return false; } else { dbgLog.fine("this file is stata-dta type: " + DTAFileReaderSpi.stataReleaseNumber.get(b[0]) + "(No in byte=" + b[0] + ")"); return true; } } @Override public boolean canDecodeInput(BufferedInputStream stream) throws IOException { if (stream == null) { throw new IllegalArgumentException("stream == null!"); } dbgLog.fine("applying the dta test\n"); byte[] b = new byte[DTA_HEADER_SIZE]; if (stream.markSupported()) { stream.mark(0); } int nbytes = stream.read(b, 0, DTA_HEADER_SIZE); if (nbytes == 0) { throw new IOException(); } //printHexDump(b, "hex dump of the byte-array"); if (stream.markSupported()) { stream.reset(); } boolean DEBUG = false; dbgLog.info("hex dump: 1st 4bytes =>" + new String(Hex.encodeHex(b)) + "<-"); if (b[2] != 1) { dbgLog.fine("3rd byte is not 1: given file is not stata-dta type"); return false; } else if ((b[1] != 1) && (b[1] != 2)) { dbgLog.fine("2nd byte is neither 0 nor 1: this file is not stata-dta type"); return false; } else if (!DTAFileReaderSpi.stataReleaseNumber.containsKey(b[0])) { dbgLog.fine("1st byte (" + b[0] + ") is not within the ingestable range [rel. 3-10]:" + "this file is NOT stata-dta type"); return false; } else { dbgLog.fine("this file is stata-dta type: " + DTAFileReaderSpi.stataReleaseNumber.get(b[0]) + "(No in HEX=" + b[0] + ")"); return true; } } @Override public boolean canDecodeInput(File file) throws IOException { if (file == null) { throw new IllegalArgumentException("file == null!"); } if (!file.canRead()) { throw new IIOException("cannot read the input file"); } // set-up a FileChannel instance for a given file object FileChannel srcChannel = new FileInputStream(file).getChannel(); // create a read-only MappedByteBuffer MappedByteBuffer buff = srcChannel.map(FileChannel.MapMode.READ_ONLY, 0, DTA_HEADER_SIZE); //printHexDump(buff, "hex dump of the byte-buffer"); buff.rewind(); boolean result = false; dbgLog.fine("applying the dta test\n"); byte[] hdr4 = new byte[4]; buff.get(hdr4, 0, 4); dbgLog.info("hex dump: 1st 4bytes =>" + new String(Hex.encodeHex(hdr4)) + "<-"); if (hdr4[2] != 1) { dbgLog.fine("3rd byte is not 1: given file is not stata-dta type"); return false; } else if ((hdr4[1] != 1) && (hdr4[1] != 2)) { dbgLog.fine("2nd byte is neither 0 nor 1: this file is not stata-dta type"); return false; } else if (!stataReleaseNumber.containsKey(hdr4[0])) { dbgLog.fine("1st byte (" + hdr4[0] + ") is not within the ingestable range [rel. 3-10]: this file is NOT stata-dta type"); return false; } else { dbgLog.fine("this file is stata-dta type: " + stataReleaseNumber.get(hdr4[0]) + "(No in HEX=" + hdr4[0] + ")"); return true; } } @Override public StatDataFileReader createReaderInstance(Object ext) throws IIOException { return new DTAFileReader(this); } }