Jarchi support for readfile from local filesystem

[rfamans]

Hi, since it is possible to use $.fs.writeFile(filePath, text) in Jarchi, would it also be possible to use $.fs.readfile in order to consume the contents of a text file on the local filesystem?

[Jean-Baptiste Sarrodie]

Hi,

In fact you can already do it through Nashorn (the JAVA-based JavaScript engine). I have an example on another laptop. I will share it later today.

Regards,

JB

[rfamans]

Ok, that would be great!

[Jean-Baptiste Sarrodie]

Hi,

Here it is:

Code Select Expand

function readFully(url) {
    var result = "";
    var imports = new JavaImporter(java.net, java.lang, java.io);

    with (imports) {

        var urlObj = null;

        try {
            urlObj = new URL(url);
        } catch (e) {
            // If the URL cannot be built, assume it is a file path.
            urlObj = new URL(new File(url).toURI().toURL());
        }

        var reader = new BufferedReader(new InputStreamReader(urlObj.openStream()));

        var line = reader.readLine();
        while (line != null) {
            result += line + "\n";
            line = reader.readLine();
        }

        reader.close();
    }

    return result;
}

Add this function to your jArchi script and you'll then be ale to use the readFully(url_or_filename) function.

Regards,

JB

[rfamans]

  Much appreciated!

[rheward]

I wanted to do something similar and I ended up repurposing smileham's import from CSV in this community script:
https://gist.github.com/smileham/1e57a5946235e780dee5a824f664aa3d

[Jean-Baptiste Sarrodie]

Hi,

Credit where credit's due : this is not my own implementation but I found it here.

Something interresting to know is that jArchi uses Nashorn which is the JavaScript engine embedded inside any JVM. This means that you have access to the whole underlying Java environment, ie. all classes.

This is very similar to NodeJS with the main difference being that NodeJS also provides a DOM (like any browser) to ease HTML document manipulation.

If you google it a bit, you'll find several code snippets and tips & tricks for Nashorn, including some polyfills to make it react a bit more like NodeJS. Some people also succeeded in loading a full-JS DOM implementation, making it easy to manipulate HTML document before loading them in the browser window included with jArchi.

Here are some links of interrest:

• https://www.n-k.de/riding-the-nashorn/
• https://blog.codecentric.de/en/2014/06/project-nashorn-javascript-jvm-polyglott/
• https://stackoverflow.com/a/39861973
• https://github.com/jazdw/domino
• https://gist.github.com/billybong/a462152889b6616deb02
• https://github.com/bripkens/java-with-javascript
• https://github.com/shendepu/nashorn-polyfill#readme
• https://gist.github.com/dasniko/6494bf2c3e0eb8dc2e8a

Regards,

JB