From CauchoWiki

Quercus 4.0.2+ exposes a command-line interface (CLI) that is easier to use than the javax.script API that comes with Java 1.6. The CLI behaves similarly to PHP's CLI.

[edit] Executing a script on the command line

CliQuercus is the class that contains the public void main() method. To execute a script, you would need to pass in the filename to CliQuercus:

 java -cp resin.jar com.caucho.quercus.CliQuercus [flags] <file> [php-args]

[edit] CliQuercus example

 java -cp resin.jar com.caucho.quercus.CliQuercus foo.php

[edit] Supported flags

The following optional flags are supported:

 -f            : Explicitly sets the script filename.
 -d name=value : Sets a php ini value.

[edit] Programmatically executing PHP scripts from within Java

The generic method to call PHP scripts from Java is through the javax.script API. Quercus also offers a simpler interface with the QuercusEngine class. By default, the output goes to System.out.

[edit] QuercusEngine example

 QuercusEngine engine = new QuercusEngine();
 engine.setIni("foo", "bar");
 engine.execute("<?php var_dump(ini_get('foo')); ?>");

[edit] File example

 QuercusEngine engine = new QuercusEngine();
 engine.executeFile("/var/www/index.php");

[edit] Returning objects example

 QuercusEngine engine = new QuercusEngine();
 // a com.caucho.quercus.env.ArrayValue is returned
 Value value = engine.execute("<?php return array(1, 2, 3) ?>");

[edit] For more information

See Resin's Javadocs.