The Asciidoctor Interface

The main entry point for AsciidoctorJ is the Asciidoctor Java interface. You obtain an instance from the factory class Asciidoctor.Factory that provides a simple create method.

If you need to get an instance of Asciidoctor using a certain gem path the factory org.asciidoctor.jruby.AsciidoctorJRuby.Factory provides multiple create methods to get an instance with a certain gem or load path:

Methods to create an Asciidoctor instance
Method Name	Description
`org.asciidoctor.Asciidoctor.Factory .create()`	The default create method that is used most often. Only use other methods if you want to load extensions that are not on the classpath.
`org.asciidoctor.jruby.AsciidoctorJRuby.Factory .create(String gemPath)`	Creates a new Asciidoctor instance and sets the global variable `GEM_PATH` to the given String. The variable `GEM_PATH` defines where Ruby looks for installed gems.
`org.asciidoctor.jruby.AsciidoctorJRuby.Factory .create(List<String> loadPaths)`	Creates a new Asciidoctor instance and set the global variable `LOAD_PATH` to the given Strings. The variable `LOAD_PATH` defines where Ruby looks for files.

So most of the time you simply get an Asciidoctor instance like this:

Default way to create an Asciidoctor instance

Asciidoctor asciidoctor = Asciidoctor.Factory.create();

As Asciidoctor instances can be created they can also be explicitly destroyed to free resources used in particular by the Ruby runtime associated with it. Therefore the Asciidoctor interface offers the method shutdown. After calling this method every other method call on the instance will fail!

Destroying an Asciidoctor instance

Asciidoctor asciidoctor = Asciidoctor.Factory.create();
asciidoctor.shutdown();

The Asciidoctor interface also implements the interface java.io.AutoCloseable which also shuts down the Ruby runtime. Therefore the previous example is equivalent to this:

Automatically destroying an Asciidoctor instance

try (Asciidoctor asciidoctor = Asciidoctor.Factory.create()) {
    Options emptyOptions = Options.builder().build();
    asciidoctor.convert("Hello World", emptyOptions);
}

To convert AsciiDoc documents the Asciidoctor interface provides four methods:

convert
convertFile
convertFiles
convertDirectory

Prior to Asciidoctor 1.5.0, the term render was used in these method names instead of convert (i.e., render, renderFile, renderFiles and renderDirectory). AsciidoctorJ continues to support the old method names for backwards compatibility.

Convert methods on the `Asciidoctor` interface
Method Name	Return Type	Description
`convert`	`String`	Parses AsciiDoc content read from a string or stream and converts it to the format specified by the `backend` option.
`convertFile`	`String`	Parses AsciiDoc content read from a file and converts it to the format specified by the `backend` option.
`convertFiles`	`String[]`	Parses a collection of AsciiDoc files and converts them to the format specified by the `backend` option.
`convertDirectory`	`String[]`	Parses all AsciiDoc files found in the specified directory (using the provided strategy) and converts them to the format specified by the `backend` option.

Here’s an example of using AsciidoctorJ to convert an AsciiDoc string.

Converting an AsciiDoc string

Options emptyOptions = Options.builder().build();
String html = asciidoctor.convert(
    "Writing AsciiDoc is _easy_!",
    emptyOptions);
System.out.println(html);

The convertFile method will convert the contents of an AsciiDoc file.

Converting an AsciiDoc file

String html = asciidoctor.convertFile(
    new File("sample.adoc"),
    Options.builder().build());
System.out.println(html);

The convertFiles method will convert a collection of AsciiDoc files:

Converting a collection of AsciiDoc files

String[] result = asciidoctor.convertFiles(
    Arrays.asList(new File("sample.adoc")),
    Options.builder().build());

for (String html : result) {
    System.out.println(html);
}

The convertFile or convertFiles methods will only return a converted String object or array if you disable writing to a file, which is enabled by default. To disable writing to a file, create a new Options object, disable the option to create a new file with option.setToFile(false), and then pass the object as a parameter to convertFile or convertFiles. To learn more check Conversion Options for a description of available customizations.

When converting directly to files, the convertFiles method will return a String Array (i.e., String[]) with the names of all the converted documents.

Another method provided by the Asciidoctor interface is convertDirectory. This method converts all of the files with AsciiDoc extensions (.adoc (preferred), .ad, .asciidoc, .asc) that are present within a specified folder and following given strategy. If the converted content is not written into files, convertDirectory will return an array listing all the documents converted.

Converting all AsciiDoc files in a directory

Options emptyOptions = Options.builder().build();
String[] result = asciidoctor.convertDirectory(
    new AsciiDocDirectoryWalker("src/asciidoc"),
    emptyOptions);

for (String html : result) {
    System.out.println(html);
}

In conjunction with convertDirectory the DirectoryWalker interface. This provides a strategy for locating files to process that can be passed as the first parameter of the convertDirectory method.

Currently, Asciidoctor provides two built-in implementations of the DirectoryWalker interface:

Built-in `DirectoryWalker` implementations
Class	Type	Description
`AsciiDocDirectoryWalker`	Concrete class	Locates all files of given folder and all its subfolders. Ignores files starting with underscore (_).
`GlobDirectoryWalker`	Concrete class	Locates all files of given folder following a glob expression.

To learn more, see Locate Files.