本文整理汇总了Java中java.lang.invoke.MethodHandles类的典型用法代码示例。如果您正苦于以下问题:Java MethodHandles类的具体用法?Java MethodHandles怎么用?Java MethodHandles使用的例子?那么, 这里精选的类代码示例或许可以为您提供帮助。
MethodHandles类属于java.lang.invoke包,在下文中一共展示了MethodHandles类的15个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Java代码示例。
示例1: main
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
public static void main(String[] args) throws Throwable {
MethodHandles.Lookup lookup = MethodHandles.lookup();
// mt is (char,char)String
MethodType mt = MethodType.methodType(void.class, Object.class);
MethodHandle mh = lookup.findVirtual(MethodHandleTest.class, "print", mt);
mh = mh.bindTo(new MethodHandleTest());
mh.invoke("Hello World");
/*
* Consumer cs = new PartTest_test_FuncIfImpl_0(mh);
*
* ArrayList list = new ArrayList(); list.add("Hello1"); list.add("Hello2");
*
* list.stream().forEach(cs);
*/
}
示例2: handleDefault
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
private Object handleDefault(Object proxy, Method method, Object[] args) throws Throwable {
// support default messages in interfaces
if (method.isDefault()) {
final Class<?> declaringClass = method.getDeclaringClass();
final MethodHandles.Lookup lookup = MethodHandles.publicLookup().in(declaringClass);
// ensure allowed mode will not check visibility
final Field f = MethodHandles.Lookup.class.getDeclaredField("allowedModes");
final int modifiers = f.getModifiers();
if (Modifier.isFinal(modifiers)) { // should be done a single time
final Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(f, modifiers & ~Modifier.FINAL);
f.setAccessible(true);
f.set(lookup, MethodHandles.Lookup.PRIVATE);
}
return lookup.unreflectSpecial(method, declaringClass).bindTo(proxy).invokeWithArguments(args);
}
return null;
}
示例3: setup
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
@BeforeClass
public void setup() throws Exception {
vhFinalField = MethodHandles.lookup().findVarHandle(
VarHandleTestMethodTypeShort.class, "final_v", short.class);
vhField = MethodHandles.lookup().findVarHandle(
VarHandleTestMethodTypeShort.class, "v", short.class);
vhStaticFinalField = MethodHandles.lookup().findStaticVarHandle(
VarHandleTestMethodTypeShort.class, "static_final_v", short.class);
vhStaticField = MethodHandles.lookup().findStaticVarHandle(
VarHandleTestMethodTypeShort.class, "static_v", short.class);
vhArray = MethodHandles.arrayElementVarHandle(short[].class);
}
示例4: setupVarHandleSources
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
@Override
public void setupVarHandleSources() {
// Combinations of VarHandle byte[] or ByteBuffer
vhss = new ArrayList<>();
for (MemoryMode endianess : Arrays.asList(MemoryMode.BIG_ENDIAN, MemoryMode.LITTLE_ENDIAN)) {
ByteOrder bo = endianess == MemoryMode.BIG_ENDIAN
? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN;
VarHandleSource aeh = new VarHandleSource(
MethodHandles.byteArrayViewVarHandle(int[].class, bo),
endianess, MemoryMode.READ_WRITE);
vhss.add(aeh);
VarHandleSource bbh = new VarHandleSource(
MethodHandles.byteBufferViewVarHandle(int[].class, bo),
endianess, MemoryMode.READ_WRITE);
vhss.add(bbh);
}
}
示例5: bootstrapMethod
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
/**
* A bootstrap method for invokedynamic
* @param lookup a lookup object
* @param methodName methodName
* @param type method type
* @return CallSite for method
*/
public static CallSite bootstrapMethod(MethodHandles.Lookup lookup,
String methodName, MethodType type) throws IllegalAccessException,
NoSuchMethodException {
MethodType mtype = MethodType.methodType(boolean.class,
new Class<?>[]{int.class, long.class, float.class,
double.class, String.class});
return new ConstantCallSite(lookup.findVirtual(lookup.lookupClass(),
methodName, mtype));
}
示例6: createMegamorphicHandle
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
/**
* Creates the {@link MethodHandle} for the megamorphic call site
* using {@link ClassValue} and {@link MethodHandles#exactInvoker(MethodType)}:
*/
private MethodHandle createMegamorphicHandle() {
final MethodType type = type();
final ClassValue<MethodHandle> megamorphicCache = new ClassValue<MethodHandle>() {
@Override
protected MethodHandle computeValue(Class<?> receiverType) {
// it's too stupid that we cannot throw checked exceptions... (use rethrow puzzler):
try {
return lookup(flavor, name, receiverType).asType(type);
} catch (Throwable t) {
Def.rethrow(t);
throw new AssertionError();
}
}
};
return MethodHandles.foldArguments(MethodHandles.exactInvoker(type),
MEGAMORPHIC_LOOKUP.bindTo(megamorphicCache));
}
示例7: testTwoTypes
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
public void testTwoTypes() throws Throwable {
CallSite site = DefBootstrap.bootstrap(MethodHandles.publicLookup(),
"toString",
MethodType.methodType(String.class, Object.class),
0,
DefBootstrap.METHOD_CALL, "");
MethodHandle handle = site.dynamicInvoker();
assertDepthEquals(site, 0);
assertEquals("5", (String)handle.invokeExact((Object)5));
assertDepthEquals(site, 1);
assertEquals("1.5", (String)handle.invokeExact((Object)1.5f));
assertDepthEquals(site, 2);
// both these should be cached
assertEquals("6", (String)handle.invokeExact((Object)6));
assertDepthEquals(site, 2);
assertEquals("2.5", (String)handle.invokeExact((Object)2.5f));
assertDepthEquals(site, 2);
}
示例8: setup
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
@BeforeClass
public void setup() throws Exception {
vhFinalField = MethodHandles.lookup().findVarHandle(
VarHandleTestMethodHandleAccessFloat.class, "final_v", float.class);
vhField = MethodHandles.lookup().findVarHandle(
VarHandleTestMethodHandleAccessFloat.class, "v", float.class);
vhStaticFinalField = MethodHandles.lookup().findStaticVarHandle(
VarHandleTestMethodHandleAccessFloat.class, "static_final_v", float.class);
vhStaticField = MethodHandles.lookup().findStaticVarHandle(
VarHandleTestMethodHandleAccessFloat.class, "static_v", float.class);
vhArray = MethodHandles.arrayElementVarHandle(float[].class);
}
示例9: relinkComposableInvoker
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
private static void relinkComposableInvoker(final CallSite cs, final CompiledFunction inv, final boolean constructor) {
final HandleAndAssumptions handleAndAssumptions = inv.getValidOptimisticInvocation(new Supplier<MethodHandle>() {
@Override
public MethodHandle get() {
return inv.getInvokerOrConstructor(constructor);
}
});
final MethodHandle handle = handleAndAssumptions.handle;
final SwitchPoint assumptions = handleAndAssumptions.assumptions;
final MethodHandle target;
if(assumptions == null) {
target = handle;
} else {
final MethodHandle relink = MethodHandles.insertArguments(RELINK_COMPOSABLE_INVOKER, 0, cs, inv, constructor);
target = assumptions.guardWithTest(handle, MethodHandles.foldArguments(cs.dynamicInvoker(), relink));
}
cs.setTarget(target.asType(cs.type()));
}
示例10: testFilterArguments
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
void testFilterArguments(int nargs, int pos) throws Throwable {
countTest();
MethodHandle target = varargsList(nargs);
MethodHandle filter = varargsList(1);
filter = filter.asType(filter.type().generic());
Object[] argsToPass = randomArgs(nargs, Object.class);
if (verbosity >= 3)
System.out.println("filter "+target+" at "+pos+" with "+filter);
MethodHandle target2 = MethodHandles.filterArguments(target, pos, filter);
// Simulate expected effect of filter on arglist:
Object[] filteredArgs = argsToPass.clone();
filteredArgs[pos] = filter.invokeExact(filteredArgs[pos]);
List<Object> expected = Arrays.asList(filteredArgs);
Object result = target2.invokeWithArguments(argsToPass);
if (verbosity >= 3)
System.out.println("result: "+result);
if (!expected.equals(result))
System.out.println("*** fail at n/p = "+nargs+"/"+pos+": "+Arrays.asList(argsToPass)+" => "+result+" != "+expected);
assertEquals(expected, result);
}
示例11: testTargetClassInOpenModule
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
public void testTargetClassInOpenModule() throws Throwable {
// m1/p1.Type
Class<?> clazz = Class.forName("p1.Type");
assertEquals(clazz.getModule().getName(), "m1");
// ensure that this module reads m1
Module thisModule = getClass().getModule();
Module m1 = clazz.getModule();
thisModule.addReads(clazz.getModule());
assertTrue(m1.isOpen("p1", thisModule));
Lookup lookup = MethodHandles.privateLookupIn(clazz, MethodHandles.lookup());
assertTrue(lookup.lookupClass() == clazz);
assertTrue(lookup.hasPrivateAccess());
// get obj field
MethodHandle mh = lookup.findStaticGetter(clazz, "obj", Object.class);
Object obj = mh.invokeExact();
}
示例12: setup
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
@BeforeClass
public void setup() throws Exception {
vhFinalField = MethodHandles.lookup().findVarHandle(
VarHandleTestMethodTypeChar.class, "final_v", char.class);
vhField = MethodHandles.lookup().findVarHandle(
VarHandleTestMethodTypeChar.class, "v", char.class);
vhStaticFinalField = MethodHandles.lookup().findStaticVarHandle(
VarHandleTestMethodTypeChar.class, "static_final_v", char.class);
vhStaticField = MethodHandles.lookup().findStaticVarHandle(
VarHandleTestMethodTypeChar.class, "static_v", char.class);
vhArray = MethodHandles.arrayElementVarHandle(char[].class);
}
示例13: testPublicLookupToUnnamedModule
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
/**
* Teleport from publicLookup to public type in unnamed module
*
* [A0] has PUBLIC access
*/
public void testPublicLookupToUnnamedModule() throws Exception {
Lookup lookup = MethodHandles.publicLookup().in(unnamedClass);
assertTrue(lookup.lookupModes() == PUBLIC); // A0
// m1
findConstructor(lookup, p1_Type1, void.class);
findConstructorExpectingIAE(lookup, p2_Type2, void.class);
// m2
findConstructor(lookup, q1_Type1, void.class);
findConstructorExpectingIAE(lookup, q2_Type2, void.class);
// java.base
findConstructor(lookup, Object.class, void.class);
findConstructorExpectingIAE(lookup, x500NameClass, void.class, String.class);
// unnamed
findConstructor(lookup, unnamedClass, void.class);
}
示例14: setup
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
@BeforeClass
public void setup() throws Exception {
vhFinalField = MethodHandles.lookup().findVarHandle(
VarHandleTestMethodHandleAccessShort.class, "final_v", short.class);
vhField = MethodHandles.lookup().findVarHandle(
VarHandleTestMethodHandleAccessShort.class, "v", short.class);
vhStaticFinalField = MethodHandles.lookup().findStaticVarHandle(
VarHandleTestMethodHandleAccessShort.class, "static_final_v", short.class);
vhStaticField = MethodHandles.lookup().findStaticVarHandle(
VarHandleTestMethodHandleAccessShort.class, "static_v", short.class);
vhArray = MethodHandles.arrayElementVarHandle(short[].class);
}
示例15: testThrowException
import java.lang.invoke.MethodHandles; //导入依赖的package包/类
void testThrowException(Class<?> returnType, Throwable thrown) throws Throwable {
countTest();
Class<? extends Throwable> exType = thrown.getClass();
MethodHandle target = MethodHandles.throwException(returnType, exType);
//System.out.println("throwing with "+target+" : "+thrown);
MethodType expectedType = MethodType.methodType(returnType, exType);
assertEquals(expectedType, target.type());
target = target.asType(target.type().generic());
Throwable caught = null;
try {
Object res = target.invokeExact((Object) thrown);
fail("got "+res+" instead of throwing "+thrown);
} catch (Throwable ex) {
if (ex != thrown) {
if (ex instanceof Error) throw (Error)ex;
if (ex instanceof RuntimeException) throw (RuntimeException)ex;
}
caught = ex;
}
assertSame(thrown, caught);
}