public CompiledScript compile()

in src/main/java/org/apache/maven/plugins/scripting/engine/JavaEngine.java [91:168]
71 lines of code
6 McCabe index (conditional complexity)

    public CompiledScript compile(String script) throws ScriptException {
        // plexus compiler is great but overkill there so don't bring it just for that
        final JavaCompiler compiler =
                requireNonNull(ToolProvider.getSystemJavaCompiler(), "you must run on a JDK to have a compiler");
        Path tmpDir = null;
        try {
            tmpDir = Files.createTempDirectory(getClass().getSimpleName());

            final String packageName = getClass().getPackage().getName() + ".generated";
            final String className = "JavaCompiledScript_" + Math.abs(script.hashCode());
            final String source = toSource(packageName, className, script);
            final Path src = tmpDir.resolve("sources");
            final Path bin = tmpDir.resolve("bin");
            final Path srcDir = src.resolve(packageName.replace('.', '/'));
            Files.createDirectories(srcDir);
            Files.createDirectories(bin);
            final Path java = srcDir.resolve(className + ".java");
            try (Writer writer = Files.newBufferedWriter(java)) {
                writer.write(source);
            }

            // TODO: make it configurable from the project in subsequent releases
            final String classpath = mavenClasspathPrefix()
                    + System.getProperty(
                            getClass().getName() + ".classpath",
                            System.getProperty("java.class.path", System.getProperty("surefire.real.class.path")));

            // TODO: use a Logger in subsequent releases. Not very important as of now, so using std streams
            final int run = compiler.run(
                    null,
                    System.out,
                    System.err,
                    Stream.of(
                                    "-classpath",
                                    classpath,
                                    "-sourcepath",
                                    src.toAbsolutePath().toString(),
                                    "-d",
                                    bin.toAbsolutePath().toString(),
                                    java.toAbsolutePath().toString())
                            .toArray(String[]::new));
            if (run != 0) {
                throw new IllegalArgumentException(
                        "Can't compile the incoming script, here is the generated code: >\n" + source + "\n<\n");
            }
            final URLClassLoader loader = new URLClassLoader(
                    new URL[] {bin.toUri().toURL()}, Thread.currentThread().getContextClassLoader());
            final Class<? extends CompiledScript> loadClass =
                    loader.loadClass(packageName + '.' + className).asSubclass(CompiledScript.class);
            return loadClass
                    .getConstructor(ScriptEngine.class, URLClassLoader.class)
                    .newInstance(this, loader);
        } catch (Exception e) {
            throw new ScriptException(e);
        } finally {
            if (tmpDir != null) {
                try {
                    Files.walkFileTree(tmpDir, new SimpleFileVisitor<Path>() {
                        @Override
                        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
                            Files.delete(file);
                            return FileVisitResult.CONTINUE;
                        }

                        @Override
                        public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
                            Files.delete(dir);
                            return FileVisitResult.CONTINUE;
                        }
                    });
                } catch (IOException e) {
                    if (log != null) {
                        log.debug(e);
                    }
                }
            }
        }
    }