Java8 Lambda and its disassembled bytecode by javap

disassembled bytecode of Foo.class

Classfile /***/Foo.class
  Last modified 2014/01/22; size 1603 bytes
  MD5 checksum 79b51e1db200ecc888a111f97c169832
  Compiled from "Foo.java"
class Foo
  SourceFile: "Foo.java"
  InnerClasses:
       public static final #78= #77 of #81; //Lookup=class java/lang/invoke/MethodHandles$Lookup of class java/lang/invoke/MethodHandles
  BootstrapMethods:
    0: #29 invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
      Method arguments:
        #30 (Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
        #31 invokestatic Foo.f1:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
        #32 (Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
    1: #29 invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
      Method arguments:
        #30 (Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
        #35 invokespecial Foo.f2:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
        #32 (Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
    2: #29 invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
      Method arguments:
        #30 (Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
        #37 invokestatic Foo.lambda$main$0:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
        #32 (Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  minor version: 0
  major version: 52
  flags: ACC_SUPER
Constant pool:
   #1 = Methodref          #13.#26        //  java/lang/Object."<init>":()V
   #2 = Class              #27            //  Foo
   #3 = Methodref          #2.#26         //  Foo."<init>":()V
   #4 = InvokeDynamic      #0:#33         //  #0:apply:()Ljava/util/function/BiFunction;
   #5 = Methodref          #13.#34        //  java/lang/Object.getClass:()Ljava/lang/Class;
   #6 = InvokeDynamic      #1:#36         //  #1:apply:(LFoo;)Ljava/util/function/BiFunction;
   #7 = InvokeDynamic      #2:#33         //  #2:apply:()Ljava/util/function/BiFunction;
   #8 = Fieldref           #38.#39        //  java/lang/System.out:Ljava/io/PrintStream;
   #9 = Methodref          #40.#41        //  java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
  #10 = InterfaceMethodref #42.#43        //  java/util/function/BiFunction.apply:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
  #11 = Methodref          #44.#45        //  java/io/PrintStream.println:(Ljava/lang/Object;)V
  #12 = Methodref          #40.#46        //  java/lang/Integer.intValue:()I
  #13 = Class              #47            //  java/lang/Object
  #14 = Utf8               <init>
  #15 = Utf8               ()V
  #16 = Utf8               Code
  #17 = Utf8               LineNumberTable
  #18 = Utf8               main
  #19 = Utf8               ([Ljava/lang/String;)V
  #20 = Utf8               f1
  #21 = Utf8               (Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #22 = Utf8               f2
  #23 = Utf8               lambda$main$0
  #24 = Utf8               SourceFile
  #25 = Utf8               Foo.java
  #26 = NameAndType        #14:#15        //  "<init>":()V
  #27 = Utf8               Foo
  #28 = Utf8               BootstrapMethods
  #29 = MethodHandle       #6:#48         //  invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
  #30 = MethodType         #49            //  (Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
  #31 = MethodHandle       #6:#50         //  invokestatic Foo.f1:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #32 = MethodType         #21            //  (Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #33 = NameAndType        #51:#52        //  apply:()Ljava/util/function/BiFunction;
  #34 = NameAndType        #53:#54        //  getClass:()Ljava/lang/Class;
  #35 = MethodHandle       #7:#55         //  invokespecial Foo.f2:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #36 = NameAndType        #51:#56        //  apply:(LFoo;)Ljava/util/function/BiFunction;
  #37 = MethodHandle       #6:#57         //  invokestatic Foo.lambda$main$0:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #38 = Class              #58            //  java/lang/System
  #39 = NameAndType        #59:#60        //  out:Ljava/io/PrintStream;
  #40 = Class              #61            //  java/lang/Integer
  #41 = NameAndType        #62:#63        //  valueOf:(I)Ljava/lang/Integer;
  #42 = Class              #64            //  java/util/function/BiFunction
  #43 = NameAndType        #51:#49        //  apply:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
  #44 = Class              #65            //  java/io/PrintStream
  #45 = NameAndType        #66:#67        //  println:(Ljava/lang/Object;)V
  #46 = NameAndType        #68:#69        //  intValue:()I
  #47 = Utf8               java/lang/Object
  #48 = Methodref          #70.#71        //  java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
  #49 = Utf8               (Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
  #50 = Methodref          #2.#72         //  Foo.f1:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #51 = Utf8               apply
  #52 = Utf8               ()Ljava/util/function/BiFunction;
  #53 = Utf8               getClass
  #54 = Utf8               ()Ljava/lang/Class;
  #55 = Methodref          #2.#73         //  Foo.f2:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #56 = Utf8               (LFoo;)Ljava/util/function/BiFunction;
  #57 = Methodref          #2.#74         //  Foo.lambda$main$0:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #58 = Utf8               java/lang/System
  #59 = Utf8               out
  #60 = Utf8               Ljava/io/PrintStream;
  #61 = Utf8               java/lang/Integer
  #62 = Utf8               valueOf
  #63 = Utf8               (I)Ljava/lang/Integer;
  #64 = Utf8               java/util/function/BiFunction
  #65 = Utf8               java/io/PrintStream
  #66 = Utf8               println
  #67 = Utf8               (Ljava/lang/Object;)V
  #68 = Utf8               intValue
  #69 = Utf8               ()I
  #70 = Class              #75            //  java/lang/invoke/LambdaMetafactory
  #71 = NameAndType        #76:#80        //  metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
  #72 = NameAndType        #20:#21        //  f1:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #73 = NameAndType        #22:#21        //  f2:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #74 = NameAndType        #23:#21        //  lambda$main$0:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
  #75 = Utf8               java/lang/invoke/LambdaMetafactory
  #76 = Utf8               metafactory
  #77 = Class              #82            //  java/lang/invoke/MethodHandles$Lookup
  #78 = Utf8               Lookup
  #79 = Utf8               InnerClasses
  #80 = Utf8               (Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
  #81 = Class              #83            //  java/lang/invoke/MethodHandles
  #82 = Utf8               java/lang/invoke/MethodHandles$Lookup
  #83 = Utf8               java/lang/invoke/MethodHandles
{
  Foo();
    descriptor: ()V
    flags: 
    Code:
      stack=1, locals=1, args_size=1
         0: aload_0       
         1: invokespecial #1                  // Method java/lang/Object."<init>":()V
         4: return        
      LineNumberTable:
        line 2: 0

  public static void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC, ACC_STATIC
    Code:
      stack=4, locals=5, args_size=1
         0: new           #2                  // class Foo
         3: dup           
         4: invokespecial #3                  // Method "<init>":()V
         7: astore_1      
         8: invokedynamic #4,  0              // InvokeDynamic #0:apply:()Ljava/util/function/BiFunction;
        13: astore_2      
        14: aload_1       
        15: dup           
        16: invokevirtual #5                  // Method java/lang/Object.getClass:()Ljava/lang/Class;
        19: pop           
        20: invokedynamic #6,  0              // InvokeDynamic #1:apply:(LFoo;)Ljava/util/function/BiFunction;
        25: astore_3      
        26: invokedynamic #7,  0              // InvokeDynamic #2:apply:()Ljava/util/function/BiFunction;
        31: astore        4
        33: getstatic     #8                  // Field java/lang/System.out:Ljava/io/PrintStream;
        36: aload_2       
        37: iconst_3      
        38: invokestatic  #9                  // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
        41: iconst_5      
        42: invokestatic  #9                  // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
        45: invokeinterface #10,  3           // InterfaceMethod java/util/function/BiFunction.apply:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
        50: invokevirtual #11                 // Method java/io/PrintStream.println:(Ljava/lang/Object;)V
        53: getstatic     #8                  // Field java/lang/System.out:Ljava/io/PrintStream;
        56: aload_3       
        57: iconst_4      
        58: invokestatic  #9                  // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
        61: bipush        6
        63: invokestatic  #9                  // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
        66: invokeinterface #10,  3           // InterfaceMethod java/util/function/BiFunction.apply:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
        71: invokevirtual #11                 // Method java/io/PrintStream.println:(Ljava/lang/Object;)V
        74: getstatic     #8                  // Field java/lang/System.out:Ljava/io/PrintStream;
        77: aload         4
        79: iconst_5      
        80: invokestatic  #9                  // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
        83: bipush        9
        85: invokestatic  #9                  // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
        88: invokeinterface #10,  3           // InterfaceMethod java/util/function/BiFunction.apply:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
        93: invokevirtual #11                 // Method java/io/PrintStream.println:(Ljava/lang/Object;)V
        96: return        
      LineNumberTable:
        line 4: 0
        line 5: 8
        line 6: 14
        line 7: 26
        line 8: 33
        line 9: 53
        line 10: 74
        line 11: 96

  private static java.lang.Integer f1(java.lang.Integer, java.lang.Integer);
    descriptor: (Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
    flags: ACC_PRIVATE, ACC_STATIC
    Code:
      stack=2, locals=2, args_size=2
         0: aload_0       
         1: invokevirtual #12                 // Method java/lang/Integer.intValue:()I
         4: aload_1       
         5: invokevirtual #12                 // Method java/lang/Integer.intValue:()I
         8: imul          
         9: invokestatic  #9                  // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
        12: areturn       
      LineNumberTable:
        line 13: 0

  private java.lang.Integer f2(java.lang.Integer, java.lang.Integer);
    descriptor: (Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
    flags: ACC_PRIVATE
    Code:
      stack=2, locals=3, args_size=3
         0: aload_1       
         1: invokevirtual #12                 // Method java/lang/Integer.intValue:()I
         4: aload_2       
         5: invokevirtual #12                 // Method java/lang/Integer.intValue:()I
         8: imul          
         9: invokestatic  #9                  // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
        12: areturn       
      LineNumberTable:
        line 16: 0

  private static java.lang.Integer lambda$main$0(java.lang.Integer, java.lang.Integer);
    descriptor: (Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
    flags: ACC_PRIVATE, ACC_STATIC, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
         0: aload_0       
         1: invokevirtual #12                 // Method java/lang/Integer.intValue:()I
         4: aload_1       
         5: invokevirtual #12                 // Method java/lang/Integer.intValue:()I
         8: imul          
         9: invokestatic  #9                  // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
        12: areturn       
      LineNumberTable:
        line 7: 0
}

Lambda sample (Foo.java)

import java.util.function.BiFunction;
class Foo {
    public static void main(String[] args) {
        Foo o = new Foo();
        BiFunction<Integer, Integer, Integer> ff1 = Foo::f1;
        BiFunction<Integer, Integer, Integer> ff2 = o::f2;
        BiFunction<Integer, Integer, Integer> ff3 = (x, y) -> x * y;
        System.out.println(ff1.apply(3, 5)); // => 15
        System.out.println(ff2.apply(4, 6)); // => 24
        System.out.println(ff3.apply(5, 9)); // => 45
    }
    private static Integer f1(Integer x, Integer y) {
        return x * y;
    }
    private Integer f2(Integer x, Integer y) {
        return x * y;
    }
}