RedefineInterfaceMethods.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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/*
 * @test
 * @bug 8081800 8010319
 * @summary Redefine private and default interface methods
 * @requires vm.jvmti
 * @library /test/lib
 * @modules java.base/jdk.internal.misc
 * @modules java.compiler
 *          java.instrument
 *          jdk.jartool/sun.tools.jar
 * @run main RedefineClassHelper
 * @run main/othervm -javaagent:redefineagent.jar -Xlog:redefine+class*=trace RedefineInterfaceMethods
 */

// package access top-level class to avoid problem with RedefineClassHelper
// and nested types.

interface RedefineInterfaceMethods_B {
    int ORIGINAL_RETURN = 1;
    int NEW_RETURN = 2;
    private int privateMethod() {
        return ORIGINAL_RETURN;
    }
    public default int defaultMethod() {
        return privateMethod();
    }
}

public class RedefineInterfaceMethods {

    static final int RET = -2;

    public static String redefinedPrivateMethod =
        "interface RedefineInterfaceMethods_B {" +
        "    int ORIGINAL_RETURN = 1;" +
        "    int NEW_RETURN = 2;" +
        "    private int privateMethod() {" +
        "        return NEW_RETURN;" +
        "    }" +
        "    public default int defaultMethod() {" +
        "       return privateMethod();" +
        "    }" +
        "}";

    public static String redefinedDefaultMethod =
        "interface RedefineInterfaceMethods_B {" +
        "    int ORIGINAL_RETURN = 1;" +
        "    int NEW_RETURN = 2;" +
        "    private int privateMethod() {" +
        "        return ORIGINAL_RETURN;" +
        "    }" +
        "    public default int defaultMethod() {" +
        "       return RedefineInterfaceMethods.RET;" +
        "    }" +
        "}";

    static class Impl implements RedefineInterfaceMethods_B {
    }


    public static void main(String[] args) throws Exception {

        Impl impl = new Impl();

        int res = impl.defaultMethod();
        if (res != RedefineInterfaceMethods_B.ORIGINAL_RETURN)
            throw new Error("defaultMethod returned " + res +
                            " expected " + RedefineInterfaceMethods_B.ORIGINAL_RETURN);

        RedefineClassHelper.redefineClass(RedefineInterfaceMethods_B.class, redefinedPrivateMethod);

        res = impl.defaultMethod();
        if (res != RedefineInterfaceMethods_B.NEW_RETURN)
            throw new Error("defaultMethod returned " + res +
                            " expected " + RedefineInterfaceMethods_B.NEW_RETURN);

        System.gc();

        RedefineClassHelper.redefineClass(RedefineInterfaceMethods_B.class, redefinedDefaultMethod);

        res = impl.defaultMethod();
        if (res != RET)
            throw new Error("defaultMethod returned " + res +
                            " expected " + RET);
    }
}