GraalVM系列（一）：JVM的未来——GraalVM集成入门

# https://github.com/graalvm/graalvm-ce-builds/releases 下载需要的版本
# 解压，设置PATH/JAVA_HOME
# 添加多语言环境（可选，gu是GraalVM Updater的命令）
# 没有JS？因为JS内置了，GraalVM带了Node环境，支持各类常用的NPM包！
gu install ruby
gu install r
gu install python
gu install wasm
# 添加Native Image（可选，一般都会安装，这是GraalVM的一大亮点）
gu install native-image
gu install llvm-toolchain

<dependencies>
    <dependency> (1)
        <groupId>org.graalvm.sdk</groupId>
        <artifactId>graal-sdk</artifactId>
        <version>${graalvm.version}</version>
        <scope>provided</scope>
    </dependency>
    <!-- HotSpot 兼容处理 --> (2)
    <dependency>
        <groupId>org.graalvm.truffle</groupId>
        <artifactId>truffle-api</artifactId>
        <version>${graalvm.version}</version>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.graalvm.js</groupId>
        <artifactId>js</artifactId>
        <version>${graalvm.version}</version>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.graalvm.js</groupId>
        <artifactId>js-scriptengine</artifactId>
        <version>${graalvm.version}</version>
        <scope>runtime</scope>
    </dependency>
</dependencies>
...
<profiles>
    <profile>
        <id>native</id> (3)
        <dependencies>
            <!-- 去除 HotSpot 兼容处理 --> (4)
            <dependency>
                <groupId>org.graalvm.truffle</groupId>
                <artifactId>truffle-api</artifactId>
                <version>${graalvm.version}</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>org.graalvm.js</groupId>
                <artifactId>js</artifactId>
                <version>${graalvm.version}</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>org.graalvm.js</groupId>
                <artifactId>js-scriptengine</artifactId>
                <version>${graalvm.version}</version>
                <scope>provided</scope>
            </dependency>
        </dependencies>
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-surefire-plugin</artifactId> (5)
                    <configuration>
                        <argLine>
                            -agentlib:native-image-agent=access-filter-file=${project.basedir}/src/main/resources/META-INF/native-image/com.ecfront.dew/common/agent-access-filter.json,config-output-dir=${project.basedir}/src/main/resources/META-INF/native-image/com.ecfront.dew/common/
                        </argLine>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.graalvm.nativeimage</groupId>
                    <artifactId>native-image-maven-plugin</artifactId> (6)
                    <version>${graalvm.version}</version>
                    <executions>
                        <execution>
                            <goals>
                                <goal>native-image</goal>
                            </goals>
                            <phase>package</phase>
                        </execution>
                    </executions>
                    <configuration>
                        <skip>false</skip>
                        <mainClass>${mainClass}</mainClass>
                        <imageName>${imageName}</imageName>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </profile>
</profiles>

private static final ScriptEngineManager SCRIPT_ENGINE_MANAGER = new ScriptEngineManager(); (1)
private Invocable invocable;
private ScriptHelper(Invocable invocable) {
    this.invocable = invocable;
}
/**
 * Build script helper.
 *
 * @param jsFunsCode    the js funs code
 * @param addCommonCode the add common code
 * @return the script helper
 * @throws RTScriptException the rt script exception
 */
public static ScriptHelper build(String jsFunsCode, boolean addCommonCode) throwsRTScriptException {
    Compilable jsEngine = (Compilable) SCRIPT_ENGINE_MANAGER.getEngineByName("nashorn");
    if (addCommonCode) {
        jsFunsCode = "var $ = Java.type('com.ecfront.dew.common.$');\r\n" + jsFunsCode; (2)
    }
    try {
        CompiledScript script = jsEngine.compile(jsFunsCode);
        script.eval();
        return new ScriptHelper((Invocable) script.getEngine());
    } catch (ScriptException e) {
        throw new RTScriptException(e);
    }
}
/**
 * Execute.
 *
 * @param <T>       the type parameter
 * @param jsFunName the js fun name
 * @param args      the args
 * @return the t
 * @throws RTScriptException              the rt script exception
 * @throws RTReflectiveOperationException the rt reflective operation exception
 */
public <T> T execute(String jsFunName, Object... args) throws RTScriptException, RTReflectiveOperationException {
    try {
        return (T) invocable.invokeFunction(jsFunName, args);
    } catch (ScriptException e) {
        throw new RTScriptException(e);
    } catch (NoSuchMethodException e) {
        throw new RTReflectiveOperationException(e);
    }
}

    private final Context context;
    private final ScriptKind scriptKind;

    /**
     * Build script helper.
     *
     * @param scriptKind     the script kind
     * @param scriptFunsCode the script funs code
     * @param addCommonCode  the add common code
     * @return the script helper
     * @throws RTScriptException the rt script exception
     */
    public static ScriptHelper build(ScriptKind scriptKind, String scriptFunsCode, boolean addCommonCode) throws RTScriptException {
        try {
            Context context = Context.newBuilder().allowAllAccess(true).build();
            if (addCommonCode) {
                switch (scriptKind) {
                    case JS:
                        scriptFunsCode = "const $ = Java.type('com.ecfront.dew.common.$')\r\n" + scriptFunsCode;
                        break;
                    case PYTHON:
                        // ...
                    default:
                        throw new RTScriptException("Script kind {" + scriptKind.toString() + "} NOT exist.");
                }
            }
            context.eval(Source.newBuilder(scriptKind.toString(), scriptFunsCode, "src.js").build());
            return new ScriptHelper(context, scriptKind);
        } catch (IOException e) {
            throw new RTScriptException(e);
        }
    }

    /**
     * Execute.
     *
     * @param <T>         the type parameter
     * @param funName     the fun name
     * @param returnClazz the return clazz
     * @param args        the args
     * @return the t
     */
    public <T> T execute(String funName, Class<T> returnClazz, Object... args) {
        return context.getBindings(scriptKind.toString()).getMember(funName).execute(args).as(returnClazz);
    }

# 正常应该是当前的classpath，但输出为null
ClassLoader.getSystemResource("") > null
# 对于Jar包外打印，正常应该为当前的classpath，Native Image与Jar内打印一样，输出为空
new File("").getPath() >
# XX为某些Class
# 对于Jar包外打印，正常应该为当前的classpath
# 对于jar包内打印，正常应该是当前的Jar路径，但输出的是Native Image文件路径
XX.class.getProtectionDomain().getCodeSource().getLocation().getPath() > /mnt/c/Users/i/OneDrive/workspaces/1.personal/dew/dew-common/it/target/NativeImageTest
# 正常应该是当前的classpath，但输出为null
Thread.currentThread().getContextClassLoader().getResource("") > null