moothes/jbibtex

Java BibTeX API

JBibTeX

Java BibTeX and LaTeX parser and formatter library

Installation

The current version of JBibTeX is 1.0.19 (14 July, 2021).

The library JAR file (together with source and javadoc JAR files) is distributed via Maven Central repository:

<dependency>
	<groupId>org.jbibtex</groupId>
	<artifactId>jbibtex</artifactId>
	<version>1.0.19</version>
</dependency>

Usage

Parsing BibTeX

Typical scenario:

Reader reader = ...

org.jbibtex.BibTeXParser bibtexParser = new org.jbibtex.BibTeXParser();

org.jbibtex.BibTeXDatabase database = bibtexParser.parse(reader);

BibTeX parser provides two parsing modes:

• #parse(Reader). Normal mode. The parser stops when an error condition is detected.
• #parseFully(Reader). Error recovery mode. The parser skips an erroneous object definition and continues with the next object definition. The list of error conditions can be accessed via #getExceptions().

BibTeX parser performs automatic string constants and crossref fields resolution. The default behavior is to prohibit unresolved references by throwing an unchecked exception org.jbibtex.ObjectResolutionException. The default behavior can be overriden as follows:

org.jbibtex.BibTeXParser bibtexParser = new org.jbibtex.BibTeXParser(){

	@Override
	public void checkStringResolution(org.jbibtex.Key key, org.jbibtex.BibTeXString string){

		if(string == null){
			System.err.println("Unresolved string: \"" + key.getValue() + "\"");
		}
	}

	@Override
	public void checkCrossReferenceResolution(org.jbibtex.Key key, org.jbibtex.BibTeXEntry entry){

		if(entry == null){
			System.err.println("Unresolved cross-reference: \"" + key.getValue() + "\"");
		}
	}
};

Caution: Prior to JBibTeX version 1.0.12, methods org.jbibtex.BibTeXParser#parse(java.io.Reader) and org.jbibtex.LaTeXParser#parse(java.io.Reader) may throw error org.jbibtex.TokenMgrError if the input contains illegal characters or is otherwise problematic. Library users are advised to surround the affected portions of their code with appropriate try-catch statements. An unhandled org.jbibtex.TokenMgrError could terminate the JVM process.

Library users may use class org.jbibtex.CharacterFilterReader to skip illegal characters in the input:

Reader reader = ...

org.jbibtex.CharacterFilterReader filterReader = new org.jbibtex.CharacterFilterReader(reader);

bibtexParser.parse(filterReader);

Formatting BibTeX

Typical scenario:

Writer writer = ...

org.jbibtex.BibTeXDatabase database = ...

org.jbibtex.BibTeXFormatter bibtexFormatter = new org.jbibtex.BibTeXFormatter();

bibtexFormatter.format(database, writer);

Working with BibTeX databases

Iterating over all the BibTeX entries in the BibTeX database and retrieving their title field:

org.jbibtex.BibTeXDatabase database = ...

Map<org.jbibtex.Key, org.jbibtex.BibTeXEntry> entryMap = database.getEntries();

Collection<org.jbibtex.BibTeXEntry> entries = entryMap.values();
for(org.jbibtex.BibTeXEntry entry : entries){
	org.jbibtex.Value value = entry.getField(org.jbibtex.BibTeXEntry.KEY_TITLE);
	if(value == null){
		continue;
	}

	// Do something with the title value
}

BibTeX entry values could be in LaTeX data format. The easiest way to distinguish between plain text and LaTeX text values is to look for LaTeX special symbols \ and {:

org.jbibtex.Value value = ...

String string = value.toUserString();
if(string.indexOf('\\') > -1 || string.indexOf('{') > -1){
	// LaTeX string that needs to be translated to plain text string
} else {
	// Plain text string
}

Translating LaTeX strings to plain text strings

Typical scenario:

String latexString = ...

org.jbibtex.LaTeXParser latexParser = new org.jbibtex.LaTeXParser();

List<org.jbibtex.LaTeXObject> latexObjects = latexParser.parse(latexString);

org.jbibtex.LaTeXPrinter latexPrinter = new org.jbibtex.LaTeXPrinter();

String plainTextString = latexPrinter.print(latexObjects);

License

JBibTeX is licensed under the BSD 3-Clause License.