[jira] [Updated] (TIKA-679) Proposal for PRT Parser

["Troy Witthoeft (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/TIKA-679?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Troy Witthoeft updated TIKA-679:
--------------------------------

    Attachment: TikaTest.prt

Can you find the text inside?

> Proposal for PRT Parser
> -----------------------
>
>                 Key: TIKA-679
>                 URL: https://issues.apache.org/jira/browse/TIKA-679
>             Project: Tika
>          Issue Type: Improvement
>          Components: mime, parser
>    Affects Versions: 0.9
>            Reporter: Troy Witthoeft
>            Priority: Minor
>              Labels: CAD, Mime, Parser, Prt, Tika
>         Attachments: TikaTest.prt
>
>   Original Estimate: 672h
>  Remaining Estimate: 672h
>
> It would be nice if Tika had support for prt CAD files.
> A preliminary prt text extractor has been created.
> {code:title=PRTParser.java|borderStyle=solid}
> package org.apache.tika.parser.prt;
> import java.io.BufferedInputStream;
> import java.io.BufferedReader;
> import java.io.IOException;
> import java.io.InputStream;
> import java.io.InputStreamReader;
> import java.io.Reader;
> import java.io.UnsupportedEncodingException;
> import java.nio.charset.Charset;
> import java.util.Collections;
> import java.util.Set;
> import org.apache.poi.util.IOUtils;
> import org.apache.tika.exception.TikaException;
> import org.apache.tika.metadata.Metadata;
> import org.apache.tika.mime.MediaType;
> import org.apache.tika.parser.ParseContext;
> import org.apache.tika.parser.Parser;
> import org.apache.tika.sax.XHTMLContentHandler;
> import org.xml.sax.ContentHandler;
> import org.xml.sax.SAXException;
> /**
>  * Description: PRT (CAD Drawing) parser. This is a very basic parser.   
>  * It also currently sets some dummy metadata.
>  */
> public class PRTParser implements Parser {
>         private static final Set<MediaType> SUPPORTED_TYPES = Collections.singleton(MediaType.application("prt"));
>         public static final String PRT_MIME_TYPE = "application/prt";
>         
> 		
>         public Set<MediaType> getSupportedTypes(ParseContext context) {
>                 return SUPPORTED_TYPES;
>         }
> 		
>         public void parse(
>                         InputStream stream, ContentHandler handler,
>                         Metadata metadata, ParseContext context)
>                         throws IOException, SAXException, TikaException {
> 						byte[] prefix = new byte[] {0x01, 0x1F};  //
> 						int pos = 0;
> 						int read;
> 						while( (read = stream.read()) > -1) {   //  Reads the next single byte of data (returns byte pos) until you hit the EOF
> 						  if(read == prefix[pos]) {				//  If the byte being read is 
> 							pos++;
> 							if(pos == prefix.length) {
> 							  // found it!
> 							  int length = stream.read();
> 							  int unknown = stream.read();
> 							  byte[] text = new byte[length];
> 							  IOUtils.readFully(stream, text);      //reads a selected byte array from the InputStream
> 							  // turn it into a string, removing null termination
> 							  // assumes it's found to be utf-8
> 							  String str = new String(text, 0, text.length, "UTF-8");
> 							  XHTMLContentHandler xhtml = new XHTMLContentHandler(handler, metadata);
> 							  xhtml.startElement("p");	
> 							  xhtml.characters(str);
> 							  xhtml.endElement("p");
> 							pos--;  
> 							}
> 						  } else {
> 							pos = 0;
> 						  }
> 						}
>         }
>         /**
>          * @deprecated This method will be removed in Apache Tika 1.0.
>          */
>         public void parse(
>                         InputStream stream, ContentHandler handler, Metadata metadata)
>                         throws IOException, SAXException, TikaException {
>                 parse(stream, handler, metadata, new ParseContext());
>         }
> }
> {code}   
> I am looking for assistance in improving this code.  I am in the process of picking apart the prt file structure.
> Here are my findings.
> The file header contains, a magic mime type, file creation date, and file description.
> The magic mime type can be identified with  <match value="0M3C" type="string" offset="8" />
> If present, the file creation date is after the identifier. It is in format YYYYMMDDhhmm. It is always in the same address, 0x001Eh-0x002Ah OR the 31st-43rd bytes.  
> If present, the user entered file description IMMEDIATELY follows date. Max chars is 498. It is always at the same address, 0x002Bh-0x021Ch OR the 43rd-540th bytes. Terminated with [00][01][C8]
> The goal is to extract the user entered text.  User text is marked by a prefix of 42 bytes.  Newest entries are at the top of the file.
> The prefix is always marked by the presence of six 3's and [E3][3F], that is followed by 10 variable bytes, then a byte signifying the length of the user input text + 1, and a null.
> GUIDE 
> [33][33][33][33][33][33][E3][3F][0#][00][00][0#][00][00][0#][0#][0#][1F][ln][00][USERINPUT TEXT][00][xx]
> EXAMPLE
> [33][33][33][33][33][33][E3][3F][00][00][00][00][00][00][00][02][01][1F][05][00][54][49][4B][41][00][0B] = TIKA
> Any pointers on how to improve the code is appreciated.
>  

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