script-access.md

ScriptAccess

ScriptAccess controls which Java members scripts can access on exported Java classes and objects.

script.getModuleManager().setScriptAccess(ScriptAccess.ALL);
script.getModuleManager().setScriptAccess(ScriptAccess.EXPLICIT);

ALL

ALL is the default mode.

In this mode, scripts can access public Java members that the runtime exposes and the security manager allows.

Use ALL only when exported values/classes are intentionally part of the script API.

EXPLICIT

EXPLICIT exposes only members annotated with:

@ScriptAccess.Export

Supported elements:

• constructors;
• public instance methods;
• public static methods;
• public instance fields;
• public static fields;
• enum constants.

Example

public final class UserService {
    private final String user;

    @ScriptAccess.Export
    public UserService(String user) {
        this.user = user;
    }

    @ScriptAccess.Export
    public String getUser() {
        return user;
    }

    public String internalToken() {
        return "hidden";
    }
}

Export:

SimpleScriptInternalModule services = new SimpleScriptInternalModule("services");
services.export(new ScriptValueExport("UserService", UserService.class));

script.getModuleManager().setScriptAccess(ScriptAccess.EXPLICIT);
script.getModuleManager().addModule(services);

JavaScript:

import { UserService } from "services";

const service = new UserService("alice");
service.getUser();      // allowed
service.internalToken;  // unavailable

GraalVM Implementation

GraalVM maps:

• ScriptAccess.ALL to HostAccess.ALL;
• ScriptAccess.EXPLICIT to HostAccess.EXPLICIT.

It also allows members annotated by ScriptAccess.Export.

Rhino Implementation

Rhino uses restricted wrappers for Java classes and Java objects when EXPLICIT is enabled.

The wrapper exposes only annotated fields, methods, and constructors. Non-exported members are hidden from scripts.

Scope of ScriptAccess

ScriptAccess affects Java members on values/classes exported through modules. It does not remove functions you explicitly export as ScriptFunctionExport.

For example, if you export execCommand as a Scriptify function, ScriptAccess.EXPLICIT does not block that function. Use smaller modules and security configuration for capability control.