This is an automated email from the ASF dual-hosted git repository. mawiesne pushed a commit to branch OPENNLP-1679-Extend-JavaDoc-of-SgmlParser in repository https://gitbox.apache.org/repos/asf/opennlp.git
commit cdc30ec3cfd9f3577b0018a53f92a690dee068fd Author: Martin Wiesner <[email protected]> AuthorDate: Sat Dec 21 12:40:26 2024 +0100 OPENNLP-1679 Extend JavaDoc of SgmlParser --- .../tools/formats/muc/DocumentSplitterStream.java | 2 +- .../java/opennlp/tools/formats/muc/SgmlParser.java | 92 ++++++++++++++-------- .../opennlp/tools/formats/muc/SgmlParserTest.java | 17 +++- 3 files changed, 75 insertions(+), 36 deletions(-) diff --git a/opennlp-tools/src/main/java/opennlp/tools/formats/muc/DocumentSplitterStream.java b/opennlp-tools/src/main/java/opennlp/tools/formats/muc/DocumentSplitterStream.java index 691ef6b6..aed10c86 100644 --- a/opennlp-tools/src/main/java/opennlp/tools/formats/muc/DocumentSplitterStream.java +++ b/opennlp-tools/src/main/java/opennlp/tools/formats/muc/DocumentSplitterStream.java @@ -69,7 +69,7 @@ class DocumentSplitterStream extends FilterObjectStream<String, String> { } } - if (docs.size() > 0) { + if (!docs.isEmpty()) { return docs.remove(0); } else { diff --git a/opennlp-tools/src/main/java/opennlp/tools/formats/muc/SgmlParser.java b/opennlp-tools/src/main/java/opennlp/tools/formats/muc/SgmlParser.java index e85e9950..9100536d 100644 --- a/opennlp-tools/src/main/java/opennlp/tools/formats/muc/SgmlParser.java +++ b/opennlp-tools/src/main/java/opennlp/tools/formats/muc/SgmlParser.java @@ -26,38 +26,61 @@ import opennlp.tools.util.InvalidFormatException; import opennlp.tools.util.StringUtil; /** - * SAX style SGML parser. - * <p> - * Note:<br> - * The implementation is very limited, but good enough to - * parse the MUC corpora. Its must very likely be extended/improved/fixed to parse - * a different SGML corpora. + * A SAX style <a href="https://www.w3.org/TR/WD-html40-970708/intro/sgmltut.html";>SGML</a> parser. + * + * @implNote The implementation is very limited, but good enough to parse the + * <a href="https://catalog.ldc.upenn.edu/LDC2003T13";>MUC corpora</a>. + * Its must very likely be extended/improved/fixed to parse a different SGML corpora. */ public class SgmlParser { - public static abstract class ContentHandler { - - public void startElement(String name, Map<String, String> attributes) throws InvalidFormatException { - } + private static final char SYMBOL_CLOSE = '>'; + private static final char SYMBOL_OPEN = '<'; + private static final char SYMBOL_SLASH = '/'; + private static final char SYMBOL_EQUALS = '='; + private static final char SYMBOL_QUOT = '"'; - public void characters(CharSequence chars) throws InvalidFormatException{ - } + /** + * Defines methods to handle content produced by a {@link SgmlParser}. + * A concrete implementation interprets the document specific details. + */ + public static abstract class ContentHandler { - public void endElement(String name) throws InvalidFormatException { - } + /** + * Handles a SGML start element. + * + * @param name The name of the element's start tag. + * @param attributes The attributes supplied with the start tag. It may be empty. + * @throws InvalidFormatException Thrown if parameters were invalid. + */ + public abstract void startElement(String name, Map<String, String> attributes) + throws InvalidFormatException; + + /** + * Handles a set of characters between SGML start and end tag. + * + * @param chars The characters to process. + * @throws InvalidFormatException Thrown if parameters were invalid. + */ + public abstract void characters(CharSequence chars) + throws InvalidFormatException; + + /** + * Handles a SGML end element. + * @param name The name of the element's end tag. + */ + public abstract void endElement(String name); } private static String extractTagName(CharSequence tagChars) throws InvalidFormatException { int fromOffset = 1; - - if (tagChars.length() > 1 && tagChars.charAt(1) == '/') { + if (tagChars.length() > 1 && tagChars.charAt(1) == SYMBOL_SLASH) { fromOffset = 2; } for (int ci = 1; ci < tagChars.length(); ci++) { - - if (tagChars.charAt(ci) == '>' || StringUtil.isWhitespace(tagChars.charAt(ci))) { + if (tagChars.charAt(ci) == SYMBOL_CLOSE || StringUtil.isWhitespace(tagChars.charAt(ci))) { return tagChars.subSequence(fromOffset, ci).toString(); } } @@ -90,7 +113,8 @@ public class SgmlParser { extractKey = true; } // Equals sign indicated end of key name - else if (extractKey && ('=' == tagChars.charAt(i) || StringUtil.isWhitespace(tagChars.charAt(i)))) { + else if (extractKey && (SYMBOL_EQUALS == tagChars.charAt(i) || + StringUtil.isWhitespace(tagChars.charAt(i)))) { extractKey = false; } // Inside key name, extract all chars @@ -98,7 +122,7 @@ public class SgmlParser { key.append(tagChars.charAt(i)); } // " Indicates begin or end of value chars - else if ('"' == tagChars.charAt(i)) { + else if (SYMBOL_QUOT == tagChars.charAt(i)) { if (extractValue) { attributes.put(key.toString(), value.toString()); @@ -107,7 +131,6 @@ public class SgmlParser { key.setLength(0); value.setLength(0); } - extractValue = !extractValue; } // Inside value, extract all chars @@ -119,6 +142,17 @@ public class SgmlParser { return attributes; } + /** + * Parses an SGML document available via the input in {@link Reader}. + * The specified {@link ContentHandler} is responsible of how to interpret the document + * specific details. + * + * @param in A {@link Reader} that provides the data of the SGML document. + * @param handler The {@link ContentHandler} to interpret the document with. + * + * @throws IOException Thrown if IO errors occurred. + * @throws InvalidFormatException Thrown if parameters were invalid. + */ public void parse(Reader in, ContentHandler handler) throws IOException { StringBuilder buffer = new StringBuilder(); @@ -130,45 +164,37 @@ public class SgmlParser { int c; while ((c = in.read()) != -1) { - if ('<' == c) { + if (SYMBOL_OPEN == c) { if (isInsideTag) { throw new InvalidFormatException("Did not expect < char!"); } - - if (buffer.toString().trim().length() > 0) { + if (!buffer.toString().trim().isEmpty()) { handler.characters(buffer.toString().trim()); } - buffer.setLength(0); - isInsideTag = true; isStartTag = true; } - buffer.appendCodePoint(c); - if ('/' == c && lastChar == '<') { + if (SYMBOL_SLASH == c && lastChar == SYMBOL_OPEN) { isStartTag = false; } - if ('>' == c) { + if (SYMBOL_CLOSE == c) { if (!isInsideTag) { throw new InvalidFormatException("Did not expect > char!"); } - if (isStartTag) { handler.startElement(extractTagName(buffer), getAttributes(buffer)); } else { handler.endElement(extractTagName(buffer)); } - buffer.setLength(0); - isInsideTag = false; } - lastChar = c; } diff --git a/opennlp-tools/src/test/java/opennlp/tools/formats/muc/SgmlParserTest.java b/opennlp-tools/src/test/java/opennlp/tools/formats/muc/SgmlParserTest.java index 486da1e0..16bd54c3 100644 --- a/opennlp-tools/src/test/java/opennlp/tools/formats/muc/SgmlParserTest.java +++ b/opennlp-tools/src/test/java/opennlp/tools/formats/muc/SgmlParserTest.java @@ -21,6 +21,7 @@ import java.io.IOException; import java.io.InputStreamReader; import java.io.Reader; import java.nio.charset.StandardCharsets; +import java.util.Map; import org.junit.jupiter.api.Test; @@ -34,9 +35,21 @@ public class SgmlParserTest extends AbstractFormatTest { try (Reader in = new InputStreamReader(getResourceStream("muc/parsertest1.sgml"), StandardCharsets.UTF_8)) { SgmlParser parser = new SgmlParser(); - parser.parse(in, new SgmlParser.ContentHandler() { - }); + parser.parse(in, new DummyContentHandler()); } } + private static class DummyContentHandler extends SgmlParser.ContentHandler { + @Override + public void startElement(String name, Map<String, String> attributes) { + } + + @Override + public void characters(CharSequence chars) { + } + + @Override + public void endElement(String name) { + } + } }
