Package org.graalvm.polyglot

Class HostAccess

java.lang.Object
org.graalvm.polyglot.HostAccess
public final class HostAccess extends Object
Represents the host access policy of a polyglot context. The host access policy specifies which methods and fields are accessible to the guest application, whenever Java host objects are accessed.

There are three predefined instances of host access policies:

  • EXPLICIT - Java host methods or fields, must be public and be annotated with @Export to make them accessible to the guest language.
  • SCOPED - Java host methods or fields, must be public and be annotated with @Export to make them accessible to the guest language. Guest-to-host callback parameter validity is scoped to the duration of the callback by default.
  • NONE - Does not allow any access to methods or fields of host objects. Java host objects may still be passed into a context, but they cannot be accessed.
  • ALL - Does allow full unrestricted access to public methods or fields of host objects. Note that this policy allows unrestricted access to reflection. It is highly discouraged from using this policy in environments where the guest application is not fully trusted.
  • CONSTRAINED host access policy suitable for a context with CONSTRAINED sandbox policy.
  • ISOLATED host access policy suitable for a context with ISOLATED sandbox policy.
  • UNTRUSTED host access policy suitable for a context with UNTRUSTED sandbox policy.
Custom host access policies can be created using newBuilder(). The builder allows to specify a custom export annotation and allowed and denied methods or fields.
Since:
19.0

  • Field Details

    • EXPLICIT

      public static final HostAccess EXPLICIT
      Predefined host access policy that allows access to public host methods or fields that were annotated with @Export and were declared in public class. This is the default configuration if Context.Builder.allowAllAccess(boolean) is false.

      Equivalent of using the following builder configuration: 

       
 HostAccess.newBuilder().allowAccessAnnotatedBy(HostAccess.Export.class).
                allowImplementationsAnnotatedBy(HostAccess.Implementable.class).
                allowImplementationsAnnotatedBy(FunctionalInterface.class).
                .build();
      Since:
      19.0

    • SCOPED

      public static final HostAccess SCOPED
      Predefined host access policy that is the same as EXPLICIT and enables method scoping of callback parameter values on top. Methods that are annotated with HostAccess.DisableMethodScoping are exempt from scoping.

      Equivalent of using the following builder configuration: 

       
 HostAccess.newBuilder().allowAccessAnnotatedBy(HostAccess.Export.class).
                 allowImplementationsAnnotatedBy(HostAccess.Implementable.class).
                 allowImplementationsAnnotatedBy(FunctionalInterface.class).
                 methodScoping(true).
                 disableMethodScopingAnnotatedBy(HostAccess.DisableMethodScoping.class)
                 .build();
      Since:
      21.3

    • ALL

      public static final HostAccess ALL
      Predefined host access policy that allows full unrestricted access to public methods or fields of public host classes. Note that this policy allows unrestricted access to reflection. It is highly discouraged from using this policy in environments where the guest application is not fully trusted. This is the default configuration if Context.Builder.allowAllAccess(boolean) is true.

      Equivalent of using the following builder configuration: 

       
 HostAccess.newBuilder()
           allowPublicAccess(true).
           allowAllImplementations(true).
           allowAllClassImplementations(true).
           allowArrayAccess(true).
           allowListAccess(true).
           allowBufferAccess(true).
           allowIterableAccess(true).
           allowIteratorAccess(true).
           allowMapAccess(true).
           allowAccessInheritance(true).
           .build();
      Since:
      19.0

    • NONE

      public static final HostAccess NONE
      Predefined host access policy that disallows any access to public host methods or fields.

      Equivalent of using the following builder configuration: 

       HostAccess.newBuilder().build();
      Since:
      19.0

    • CONSTRAINED

      public static final HostAccess CONSTRAINED
      Predefined host access policy used by Context with a SandboxPolicy.CONSTRAINED sandbox policy when the host access policy is not explicitly specified by the embedder.

      Equivalent of using the following builder configuration: 

       
 HostAccess.newBuilder().
           allowAccessAnnotatedBy(Export.class).
           allowImplementationsAnnotatedBy(Implementable.class).
           allowMutableTargetMappings().build();
      Since:
      23.0

    • ISOLATED

      public static final HostAccess ISOLATED
      Predefined host access policy used by Context with an SandboxPolicy.ISOLATED sandbox policy when the host access policy is not explicitly specified by the embedder.

      Equivalent of using the following builder configuration: 

       
 HostAccess.newBuilder(CONSTRAINED).
           methodScoping(true).build();
      Since:
      23.0

    • UNTRUSTED

      public static final HostAccess UNTRUSTED
      Predefined host access policy used by Context with an SandboxPolicy.UNTRUSTED sandbox policy when the host access policy is not explicitly specified by the embedder.

      Equivalent of using the following builder configuration: 

       
 HostAccess.newBuilder().
           allowAccessAnnotatedBy(Export.class).
           allowMutableTargetMappings().
           methodScoping(true).build();
      Since:
      23.0

  • Method Details

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object
      Since:
      20.3

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object
      Since:
      20.3

    • newBuilder

      public static HostAccess.Builder newBuilder()
      Creates a new builder that allows to create a custom host access policy. The builder configuration needs to be completed using the method.
      Since:
      19.0

    • newBuilder

      public static HostAccess.Builder newBuilder(HostAccess conf)
      Creates a new builder that allows to create a custom host access policy based of a preset configuration. The preset configuration is copied and used as a template for the returned buidler. The builder configuration needs to be completed using the method.
      Since:
      19.0

    • toString

      public String toString()
      Overrides:
      toString in class Object
      Since:
      19.0