Java Code Examples for java.lang.invoke.MethodHandles.Lookup#findVirtual()

The following examples show how to use java.lang.invoke.MethodHandles.Lookup#findVirtual() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
Source File: LambdaDesugaring.java    From bazel with Apache License 2.0 6 votes vote down vote up 
/**
 * Produces a {@link MethodHandle} using either the context or {@link #targetLoader} class
 * loader, depending on {@code target}.
 */
private MethodHandle toMethodHandle(Lookup lookup, Handle asmHandle, boolean target)
    throws ReflectiveOperationException {
  Class<?> owner = loadFromInternal(asmHandle.getOwner());
  MethodType signature =
      MethodType.fromMethodDescriptorString(
          asmHandle.getDesc(),
          target ? targetLoader : Thread.currentThread().getContextClassLoader());
  switch (asmHandle.getTag()) {
    case Opcodes.H_INVOKESTATIC:
      return lookup.findStatic(owner, asmHandle.getName(), signature);
    case Opcodes.H_INVOKEVIRTUAL:
    case Opcodes.H_INVOKEINTERFACE:
      return lookup.findVirtual(owner, asmHandle.getName(), signature);
    case Opcodes.H_INVOKESPECIAL: // we end up calling these using invokevirtual
      return lookup.findSpecial(owner, asmHandle.getName(), signature, owner);
    case Opcodes.H_NEWINVOKESPECIAL:
      return lookup.findConstructor(owner, signature);
    default:
      throw new UnsupportedOperationException("Cannot resolve " + asmHandle);
  }
}
Example 2
Source File: LookupTest.java    From openjdk-jdk9 with GNU General Public License v2.0 6 votes vote down vote up 
public static void main(String... args) throws Throwable {
    // Get a full power lookup
    Lookup lookup1 =  MethodHandles.lookup();
    MethodHandle mh1 = lookup1.findStatic(lookup1.lookupClass(),
                                          "foo",
                                          methodType(String.class));
    assertEquals((String) mh1.invokeExact(), foo());

    // access protected member
    MethodHandle mh2 = lookup1.findVirtual(java.lang.ClassLoader.class,
                                           "getPackage",
                                           methodType(Package.class, String.class));
    ClassLoader loader = ClassLoader.getPlatformClassLoader();
    Package pkg = (Package)mh2.invokeExact(loader, "java.lang");
    assertEquals(pkg.getName(), "java.lang");

    // MethodHandles.lookup will fail if it's called reflectively
    try {
        MethodHandles.class.getMethod("lookup").invoke(null);
    } catch (InvocationTargetException e) {
        if (!(e.getCause() instanceof IllegalArgumentException)) {
            throw e.getCause();
        }
    }
}
Example 3
Source File: MethodHandlesTest.java    From openjdk-jdk9 with GNU General Public License v2.0 5 votes vote down vote up 
public void testUserClassInSignature0() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 4
Source File: MethodHandlesTest.java    From jdk8u-dev-jdk with GNU General Public License v2.0 5 votes vote down vote up 
@Test
public void testUserClassInSignature() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 5
Source File: MethodHandlesTest.java    From jdk8u-jdk with GNU General Public License v2.0 5 votes vote down vote up 
@Test
public void testUserClassInSignature() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 6
Source File: MethodHandlesTest.java    From jdk8u_jdk with GNU General Public License v2.0 5 votes vote down vote up 
public void testUserClassInSignature0() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 7
Source File: MethodHandlesTest.java    From openjdk-8 with GNU General Public License v2.0 5 votes vote down vote up 
@Test
public void testUserClassInSignature() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 8
Source File: MethodHandlesTest.java    From openjdk-8-source with GNU General Public License v2.0 5 votes vote down vote up 
@Test
public void testUserClassInSignature() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 9
Source File: MethodHandlesTest.java    From hottub with GNU General Public License v2.0 5 votes vote down vote up 
public void testUserClassInSignature0() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 10
Source File: MethodHandlesTest.java    From jdk8u-jdk with GNU General Public License v2.0 5 votes vote down vote up 
public void testUserClassInSignature0() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 11
Source File: MethodHandlesTest.java    From dragonwell8_jdk with GNU General Public License v2.0 5 votes vote down vote up 
public void testUserClassInSignature0() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 12
Source File: ReflectionFrames.java    From openjdk-jdk9 with GNU General Public License v2.0 5 votes vote down vote up 
public static Class<?> handleCaller() throws Exception {
    Lookup lookup = MethodHandles.lookup();
    MethodHandle mh = lookup.findVirtual(StackWalker.class, "getCallerClass",
            MethodType.methodType(Class.class));
    try {
        return (Class<?>) mh.invoke(walker.get());
    } catch (Error | Exception x) {
        throw x;
    } catch(Throwable t) {
        throw new AssertionError(t);
    }
}
Example 13
Source File: StringConcatFactory.java    From openjdk-jdk9 with GNU General Public License v2.0 5 votes vote down vote up 
static MethodHandle lookupVirtual(Lookup lookup, Class<?> refc, String name, Class<?> rtype, Class<?>... ptypes) {
    try {
        return lookup.findVirtual(refc, name, MethodType.methodType(rtype, ptypes));
    } catch (NoSuchMethodException | IllegalAccessException e) {
        throw new AssertionError(e);
    }
}
Example 14
Source File: StringConcatFactory.java    From Bytecoder with Apache License 2.0 5 votes vote down vote up 
static MethodHandle lookupVirtual(Lookup lookup, Class<?> refc, String name, Class<?> rtype, Class<?>... ptypes) {
    try {
        return lookup.findVirtual(refc, name, MethodType.methodType(rtype, ptypes));
    } catch (NoSuchMethodException | IllegalAccessException e) {
        throw new AssertionError(e);
    }
}
Example 15
Source File: MethodHandlesTest.java    From openjdk-jdk8u-backup with GNU General Public License v2.0 5 votes vote down vote up 
public void testUserClassInSignature0() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 16
Source File: MethodHandlesTest.java    From openjdk-jdk8u with GNU General Public License v2.0 5 votes vote down vote up 
public void testUserClassInSignature0() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 17
Source File: LoggerImpl.java    From beautiful_logger with MIT License 5 votes vote down vote up 
private static MethodHandle mh(Lookup lookup, String name) {
  try {
    return lookup.findVirtual(ch.qos.logback.classic.Logger.class, name, methodType(void.class, String.class, Throwable.class));
  } catch (NoSuchMethodException | IllegalAccessException e) {
    throw new AssertionError(e);
  }
}
Example 18
Source File: LoggerImpl.java    From beautiful_logger with MIT License 5 votes vote down vote up 
private static MethodHandle mh(Lookup lookup, String name) {
  try {
    return lookup.findVirtual(org.slf4j.Logger.class, name, methodType(void.class, String.class, Throwable.class));
  } catch (NoSuchMethodException | IllegalAccessException e) {
    throw new AssertionError(e);
  }
}
Example 19
Source File: MethodHandlesTest.java    From jdk8u60 with GNU General Public License v2.0 5 votes vote down vote up 
public void testUserClassInSignature0() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}
Example 20
Source File: MethodHandlesTest.java    From TencentKona-8 with GNU General Public License v2.0 5 votes vote down vote up 
public void testUserClassInSignature0() throws Throwable {
    if (CAN_SKIP_WORKING)  return;
    startTest("testUserClassInSignature");
    Lookup lookup = MethodHandles.lookup();
    String name; MethodType mt; MethodHandle mh;
    Object[] args;

    // Try a static method.
    name = "userMethod";
    mt = MethodType.methodType(Example.class, Object.class, String.class, int.class);
    mh = lookup.findStatic(lookup.lookupClass(), name, mt);
    assertEquals(mt, mh.type());
    assertEquals(Example.class, mh.type().returnType());
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);

    // Try a virtual method.
    name = "v2";
    mt = MethodType.methodType(Object.class, Object.class, int.class);
    mh = lookup.findVirtual(Example.class, name, mt);
    assertEquals(mt, mh.type().dropParameterTypes(0,1));
    assertTrue(mh.type().parameterList().contains(Example.class));
    args = randomArgs(mh.type().parameterArray());
    mh.invokeWithArguments(args);
    assertCalled(name, args);
}