如何在 Java 应用程序中使用 GraalVM SDK 库？

Question

I do not know how to compile my Java application with GraalVM's SDK. I believe they are added to the classpath by default when using the GraalVM javac binary.

My hello world test application:

import java.io.File;
import org.graalvm.polygot.Source;
import org.graalvm.polygot.Context;

public class Application
{
    public static void main() {
        System.out.println("Hello, world");
    }
}

javac output:

$ javac Application.java
Application.java:2: error: package org.graalvm.polygot does not exist
import org.graalvm.polygot.Source;
                          ^
Application.java:3: error: package org.graalvm.polygot does not exist
import org.graalvm.polygot.Context;
                          ^
2 errors

I am using the GraalVM javac binary built with OpenJDK 11:

$ java --version
openjdk 11.0.8 2020-07-14
OpenJDK Runtime Environment GraalVM CE 20.2.0 (build 11.0.8+10-jvmci-20.2-b03)
OpenJDK 64-Bit Server VM GraalVM CE 20.2.0 (build 11.0.8+10-jvmci-20.2-b03, mixed mode, sharing)

$ env | grep JAVA
JAVA_HOME=/home/matt/Software/graalvm-ce-java11-20.2.0

When digging deeper, I found the classes to be contained within .jmod archives at $JAVA_HOME/jmod :

$ jmod list org.graalvm.sdk.jmod | grep Source
classes/org/graalvm/polyglot/Source.class

$ jmod list org.graalvm.sdk.jmod | grep Context.class
classes/org/graalvm/polyglot/Context.class

Answer 1

These classes and packages get on the classpath automatically.

You have a typo in the import statements: polygot -> polyglot .

Note that I've also added the String[] args as the argument to the main method so it has the correct signature and can be run.

Here's my output when I compile/run it.

~/1 ~/.sdkman/candidates/java/20.2.0.r11-grl/bin/java -version
openjdk version "11.0.8" 2020-07-14
OpenJDK Runtime Environment GraalVM CE 20.2.0 (build 11.0.8+10-jvmci-20.2-b03)
OpenJDK 64-Bit Server VM GraalVM CE 20.2.0 (build 11.0.8+10-jvmci-20.2-b03, mixed mode, sharing)

~/1 cat Application.java
───────┬───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
       │ File: Application.java
───────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1   │ import java.io.File;
   2   │ import org.graalvm.polyglot.Source;
   3   │ import org.graalvm.polyglot.Context;
   4   │
   5   │ public class Application
   6   │ {
   7   │     public static void main(String[] args) {
   8   │         System.out.println("Hello, world");
   9   │     }
  10   │ }
───────┴───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────

~/1 ~/.sdkman/candidates/java/20.2.0.r11-grl/bin/javac Application.java

~/1 ll
total 8
-rw-rw-r--. 1 opc opc 428 Nov  2 10:39 Application.class
-rw-rw-r--. 1 opc opc 219 Nov  2 10:39 Application.java

~/1 ~/.sdkman/candidates/java/20.2.0.r11-grl/bin/java Application
Hello, world
~/1