我对是否有与lambda表达式相关联的对象感到困惑，因为据说在lambda表达式的情况下“ this”不引用lambda表达式的对象，因为lambda表达式没有有任何对象，但又有人说，如果lambda表达式未捕获外部作用域中的变量，则每次lambda表达式的调用都将使用同一单例对象。
现在，我假设将有一个与lambda表达式关联的对象（我想这回答了我的第一个问题，如果我错了，请纠正我），所以我的问题是那就是为什么“ this”不引用lambda表达式的对象，就像匿名类的情况一样。
import java.util.function.Consumer;
public class LambdaByteCodeAnalysis1 {
public static void main(String[] args) {
testConsumer();
}
private static void testConsumer() {
// *** void accept(T t); ***
testConsumerImpl((value) -> System.out.println("Hello, Mr. " + value));
}
private static void testConsumerImpl(Consumer<Object> consumer) {
consumer.accept("testConsumer");
}
}
##############
import java.util.function.Consumer;
public class LambdaByteCodeAnalysis2 {
public static void main(String[] args) {
testConsumer();
}
private static void testConsumer() {
int testing = 0;
testConsumerImpl((value) -> {
System.out.println("Hello, Mr. " + value);
System.out.println(testing);
});
}
private static void testConsumerImpl(Consumer<Object> consumer) {
consumer.accept("testConsumer");
}
}
################
import java.util.function.Consumer;
public class LambdaByteCodeAnalysis3 {
int testing = 0;
public static void main(String[] args) {
testConsumer();
}
private static void testConsumer() {
LambdaByteCodeAnalysis3 lambdaByteCodeAnalysis3 = new LambdaByteCodeAnalysis3();
testConsumerImpl((value) -> {
System.out.println("Hello, Mr. " + value);
System.out.println(lambdaByteCodeAnalysis3.testing);
});
}
private static void testConsumerImpl(Consumer<Object> consumer) {
consumer.accept("testConsumer");
}
}
现在，字节码的顺序相同：
LambdaByteCodeAnalysis1.class
C:\E_Drive\Projects\SourceCode\Learning\learn\src\com\learn\oracle\LearningJavaLang\ClassesAndObject\LamdaExpression>javap -v LambdaByteCodeAnalysis1
Classfile /C:/E_Drive/Projects/SourceCode/Learning/learn/src/com/learn/oracle/LearningJavaLang/ClassesAndObject/LamdaExpression/LambdaByteCodeAnalysis1.class
Last modified 15 Aug, 2018; size 1574 bytes
MD5 checksum d90045ca82de96636d8fc91f54637c32
Compiled from "LambdaByteCodeAnalysis1.java"
public class LambdaByteCodeAnalysis1
minor version: 0
major version: 52
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Methodref #16.#32 // java/lang/Object."<init>":()V
#2 = Methodref #15.#33 // LambdaByteCodeAnalysis1.testConsumer:()V
#3 = InvokeDynamic #0:#38 // #0:accept:()Ljava/util/function/Consumer;
#4 = Methodref #15.#39 // LambdaByteCodeAnalysis1.testConsumerImpl:(Ljava/util/function/Consumer;)V
#5 = String #23 // testConsumer
#6 = InterfaceMethodref #40.#41 // java/util/function/Consumer.accept:(Ljava/lang/Object;)V
#7 = Fieldref #42.#43 // java/lang/System.out:Ljava/io/PrintStream;
#8 = Class #44 // java/lang/StringBuilder
#9 = Methodref #8.#32 // java/lang/StringBuilder."<init>":()V
#10 = String #45 // Hello, Mr.
#11 = Methodref #8.#46 // java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
#12 = Methodref #8.#47 // java/lang/StringBuilder.append:(Ljava/lang/Object;)Ljava/lang/StringBuilder;
#13 = Methodref #8.#48 // java/lang/StringBuilder.toString:()Ljava/lang/String;
#14 = Methodref #49.#50 // java/io/PrintStream.println:(Ljava/lang/String;)V
#15 = Class #51 // LambdaByteCodeAnalysis1
#16 = Class #52 // java/lang/Object
#17 = Utf8 <init>
#18 = Utf8 ()V
#19 = Utf8 Code
#20 = Utf8 LineNumberTable
#21 = Utf8 main
#22 = Utf8 ([Ljava/lang/String;)V
#23 = Utf8 testConsumer
#24 = Utf8 testConsumerImpl
#25 = Utf8 (Ljava/util/function/Consumer;)V
#26 = Utf8 Signature
#27 = Utf8 (Ljava/util/function/Consumer<Ljava/lang/Object;>;)V
#28 = Utf8 lambda$testConsumer$0
#29 = Utf8 (Ljava/lang/Object;)V
#30 = Utf8 SourceFile
#31 = Utf8 LambdaByteCodeAnalysis1.java
#32 = NameAndType #17:#18 // "<init>":()V
#33 = NameAndType #23:#18 // testConsumer:()V
#34 = Utf8 BootstrapMethods
#35 = MethodHandle #6:#53 // invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/Stri
ng;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#36 = MethodType #29 // (Ljava/lang/Object;)V
#37 = MethodHandle #6:#54 // invokestatic LambdaByteCodeAnalysis1.lambda$testConsumer$0:(Ljava/lang/Object;)V
#38 = NameAndType #55:#56 // accept:()Ljava/util/function/Consumer;
#39 = NameAndType #24:#25 // testConsumerImpl:(Ljava/util/function/Consumer;)V
#40 = Class #57 // java/util/function/Consumer
#41 = NameAndType #55:#29 // accept:(Ljava/lang/Object;)V
#42 = Class #58 // java/lang/System
#43 = NameAndType #59:#60 // out:Ljava/io/PrintStream;
#44 = Utf8 java/lang/StringBuilder
#45 = Utf8 Hello, Mr.
#46 = NameAndType #61:#62 // append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
#47 = NameAndType #61:#63 // append:(Ljava/lang/Object;)Ljava/lang/StringBuilder;
#48 = NameAndType #64:#65 // toString:()Ljava/lang/String;
#49 = Class #66 // java/io/PrintStream
#50 = NameAndType #67:#68 // println:(Ljava/lang/String;)V
#51 = Utf8 LambdaByteCodeAnalysis1
#52 = Utf8 java/lang/Object
#53 = Methodref #69.#70 // java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang
/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#54 = Methodref #15.#71 // LambdaByteCodeAnalysis1.lambda$testConsumer$0:(Ljava/lang/Object;)V
#55 = Utf8 accept
#56 = Utf8 ()Ljava/util/function/Consumer;
#57 = Utf8 java/util/function/Consumer
#58 = Utf8 java/lang/System
#59 = Utf8 out
#60 = Utf8 Ljava/io/PrintStream;
#61 = Utf8 append
#62 = Utf8 (Ljava/lang/String;)Ljava/lang/StringBuilder;
#63 = Utf8 (Ljava/lang/Object;)Ljava/lang/StringBuilder;
#64 = Utf8 toString
#65 = Utf8 ()Ljava/lang/String;
#66 = Utf8 java/io/PrintStream
#67 = Utf8 println
#68 = Utf8 (Ljava/lang/String;)V
#69 = Class #72 // java/lang/invoke/LambdaMetafactory
#70 = NameAndType #73:#77 // metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invok
e/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#71 = NameAndType #28:#29 // lambda$testConsumer$0:(Ljava/lang/Object;)V
#72 = Utf8 java/lang/invoke/LambdaMetafactory
#73 = Utf8 metafactory
#74 = Class #79 // java/lang/invoke/MethodHandles$Lookup
#75 = Utf8 Lookup
#76 = Utf8 InnerClasses
#77 = Utf8 (Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke
/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#78 = Class #80 // java/lang/invoke/MethodHandles
#79 = Utf8 java/lang/invoke/MethodHandles$Lookup
#80 = Utf8 java/lang/invoke/MethodHandles
{
public LambdaByteCodeAnalysis1();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: return
LineNumberTable:
line 3: 0
public static void main(java.lang.String[]);
descriptor: ([Ljava/lang/String;)V
flags: ACC_PUBLIC, ACC_STATIC
Code:
stack=0, locals=1, args_size=1
0: invokestatic #2 // Method testConsumer:()V
3: return
LineNumberTable:
line 6: 0
line 7: 3
}
SourceFile: "LambdaByteCodeAnalysis1.java"
InnerClasses:
public static final #75= #74 of #78; //Lookup=class java/lang/invoke/MethodHandles$Lookup of class java/lang/invoke/MethodHandles
BootstrapMethods:
0: #35 invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljav
a/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
Method arguments:
#36 (Ljava/lang/Object;)V
#37 invokestatic LambdaByteCodeAnalysis1.lambda$testConsumer$0:(Ljava/lang/Object;)V
#36 (Ljava/lang/Object;)V
C:\E_Drive\Projects\SourceCode\Learning\learn\src\com\learn\oracle\LearningJavaLang\ClassesAndObject\LamdaExpression>
LambdaByteCodeAnalysis2.class
C:\E_Drive\Projects\SourceCode\Learning\learn\src\com\learn\oracle\LearningJavaLang\ClassesAndObject\LamdaExpression>javap -v LambdaByteCodeAnalysis2
Classfile /C:/E_Drive/Projects/SourceCode/Learning/learn/src/com/learn/oracle/LearningJavaLang/ClassesAndObject/LamdaExpression/LambdaByteCodeAnalysis2.class
Last modified 15 Aug, 2018; size 1639 bytes
MD5 checksum 7e61b6b121ba9d8097f4034f331df1c9
Compiled from "LambdaByteCodeAnalysis2.java"
public class LambdaByteCodeAnalysis2
minor version: 0
major version: 52
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Methodref #17.#33 // java/lang/Object."<init>":()V
#2 = Methodref #16.#34 // LambdaByteCodeAnalysis2.testConsumer:()V
#3 = InvokeDynamic #0:#39 // #0:accept:(I)Ljava/util/function/Consumer;
#4 = Methodref #16.#40 // LambdaByteCodeAnalysis2.testConsumerImpl:(Ljava/util/function/Consumer;)V
#5 = String #24 // testConsumer
#6 = InterfaceMethodref #41.#42 // java/util/function/Consumer.accept:(Ljava/lang/Object;)V
#7 = Fieldref #43.#44 // java/lang/System.out:Ljava/io/PrintStream;
#8 = Class #45 // java/lang/StringBuilder
#9 = Methodref #8.#33 // java/lang/StringBuilder."<init>":()V
#10 = String #46 // Hello, Mr.
#11 = Methodref #8.#47 // java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
#12 = Methodref #8.#48 // java/lang/StringBuilder.append:(Ljava/lang/Object;)Ljava/lang/StringBuilder;
#13 = Methodref #8.#49 // java/lang/StringBuilder.toString:()Ljava/lang/String;
#14 = Methodref #50.#51 // java/io/PrintStream.println:(Ljava/lang/String;)V
#15 = Methodref #50.#52 // java/io/PrintStream.println:(I)V
#16 = Class #53 // LambdaByteCodeAnalysis2
#17 = Class #54 // java/lang/Object
#18 = Utf8 <init>
#19 = Utf8 ()V
#20 = Utf8 Code
#21 = Utf8 LineNumberTable
#22 = Utf8 main
#23 = Utf8 ([Ljava/lang/String;)V
#24 = Utf8 testConsumer
#25 = Utf8 testConsumerImpl
#26 = Utf8 (Ljava/util/function/Consumer;)V
#27 = Utf8 Signature
#28 = Utf8 (Ljava/util/function/Consumer<Ljava/lang/Object;>;)V
#29 = Utf8 lambda$testConsumer$0
#30 = Utf8 (ILjava/lang/Object;)V
#31 = Utf8 SourceFile
#32 = Utf8 LambdaByteCodeAnalysis2.java
#33 = NameAndType #18:#19 // "<init>":()V
#34 = NameAndType #24:#19 // testConsumer:()V
#35 = Utf8 BootstrapMethods
#36 = MethodHandle #6:#55 // invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/Stri
ng;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#37 = MethodType #56 // (Ljava/lang/Object;)V
#38 = MethodHandle #6:#57 // invokestatic LambdaByteCodeAnalysis2.lambda$testConsumer$0:(ILjava/lang/Object;)V
#39 = NameAndType #58:#59 // accept:(I)Ljava/util/function/Consumer;
#40 = NameAndType #25:#26 // testConsumerImpl:(Ljava/util/function/Consumer;)V
#41 = Class #60 // java/util/function/Consumer
#42 = NameAndType #58:#56 // accept:(Ljava/lang/Object;)V
#43 = Class #61 // java/lang/System
#44 = NameAndType #62:#63 // out:Ljava/io/PrintStream;
#45 = Utf8 java/lang/StringBuilder
#46 = Utf8 Hello, Mr.
#47 = NameAndType #64:#65 // append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
#48 = NameAndType #64:#66 // append:(Ljava/lang/Object;)Ljava/lang/StringBuilder;
#49 = NameAndType #67:#68 // toString:()Ljava/lang/String;
#50 = Class #69 // java/io/PrintStream
#51 = NameAndType #70:#71 // println:(Ljava/lang/String;)V
#52 = NameAndType #70:#72 // println:(I)V
#53 = Utf8 LambdaByteCodeAnalysis2
#54 = Utf8 java/lang/Object
#55 = Methodref #73.#74 // java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang
/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#56 = Utf8 (Ljava/lang/Object;)V
#57 = Methodref #16.#75 // LambdaByteCodeAnalysis2.lambda$testConsumer$0:(ILjava/lang/Object;)V
#58 = Utf8 accept
#59 = Utf8 (I)Ljava/util/function/Consumer;
#60 = Utf8 java/util/function/Consumer
#61 = Utf8 java/lang/System
#62 = Utf8 out
#63 = Utf8 Ljava/io/PrintStream;
#64 = Utf8 append
#65 = Utf8 (Ljava/lang/String;)Ljava/lang/StringBuilder;
#66 = Utf8 (Ljava/lang/Object;)Ljava/lang/StringBuilder;
#67 = Utf8 toString
#68 = Utf8 ()Ljava/lang/String;
#69 = Utf8 java/io/PrintStream
#70 = Utf8 println
#71 = Utf8 (Ljava/lang/String;)V
#72 = Utf8 (I)V
#73 = Class #76 // java/lang/invoke/LambdaMetafactory
#74 = NameAndType #77:#81 // metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invok
e/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#75 = NameAndType #29:#30 // lambda$testConsumer$0:(ILjava/lang/Object;)V
#76 = Utf8 java/lang/invoke/LambdaMetafactory
#77 = Utf8 metafactory
#78 = Class #83 // java/lang/invoke/MethodHandles$Lookup
#79 = Utf8 Lookup
#80 = Utf8 InnerClasses
#81 = Utf8 (Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke
/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#82 = Class #84 // java/lang/invoke/MethodHandles
#83 = Utf8 java/lang/invoke/MethodHandles$Lookup
#84 = Utf8 java/lang/invoke/MethodHandles
{
public LambdaByteCodeAnalysis2();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: return
LineNumberTable:
line 3: 0
public static void main(java.lang.String[]);
descriptor: ([Ljava/lang/String;)V
flags: ACC_PUBLIC, ACC_STATIC
Code:
stack=0, locals=1, args_size=1
0: invokestatic #2 // Method testConsumer:()V
3: return
LineNumberTable:
line 6: 0
line 7: 3
}
SourceFile: "LambdaByteCodeAnalysis2.java"
InnerClasses:
public static final #79= #78 of #82; //Lookup=class java/lang/invoke/MethodHandles$Lookup of class java/lang/invoke/MethodHandles
BootstrapMethods:
0: #36 invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljav
a/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
Method arguments:
#37 (Ljava/lang/Object;)V
#38 invokestatic LambdaByteCodeAnalysis2.lambda$testConsumer$0:(ILjava/lang/Object;)V
#37 (Ljava/lang/Object;)V
C:\E_Drive\Projects\SourceCode\Learning\learn\src\com\learn\oracle\LearningJavaLang\ClassesAndObject\LamdaExpression>
LambdaByteCodeAnalysis3.class
C:\E_Drive\Projects\SourceCode\Learning\learn\src\com\learn\oracle\LearningJavaLang\ClassesAndObject\LamdaExpression>javap -v LambdaByteCodeAnalysis3
Classfile /C:/E_Drive/Projects/SourceCode/Learning/learn/src/com/learn/oracle/LearningJavaLang/ClassesAndObject/LamdaExpression/LambdaByteCodeAnalysis3.class
Last modified 15 Aug, 2018; size 1742 bytes
MD5 checksum 18bf579a4a95e700e29ec7e35bbac1b4
Compiled from "LambdaByteCodeAnalysis3.java"
public class LambdaByteCodeAnalysis3
minor version: 0
major version: 52
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Methodref #19.#37 // java/lang/Object."<init>":()V
#2 = Fieldref #4.#38 // LambdaByteCodeAnalysis3.testing:I
#3 = Methodref #4.#39 // LambdaByteCodeAnalysis3.testConsumer:()V
#4 = Class #40 // LambdaByteCodeAnalysis3
#5 = Methodref #4.#37 // LambdaByteCodeAnalysis3."<init>":()V
#6 = InvokeDynamic #0:#45 // #0:accept:(LLambdaByteCodeAnalysis3;)Ljava/util/function/Consumer;
#7 = Methodref #4.#46 // LambdaByteCodeAnalysis3.testConsumerImpl:(Ljava/util/function/Consumer;)V
#8 = String #28 // testConsumer
#9 = InterfaceMethodref #47.#48 // java/util/function/Consumer.accept:(Ljava/lang/Object;)V
#10 = Fieldref #49.#50 // java/lang/System.out:Ljava/io/PrintStream;
#11 = Class #51 // java/lang/StringBuilder
#12 = Methodref #11.#37 // java/lang/StringBuilder."<init>":()V
#13 = String #52 // Hello, Mr.
#14 = Methodref #11.#53 // java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
#15 = Methodref #11.#54 // java/lang/StringBuilder.append:(Ljava/lang/Object;)Ljava/lang/StringBuilder;
#16 = Methodref #11.#55 // java/lang/StringBuilder.toString:()Ljava/lang/String;
#17 = Methodref #56.#57 // java/io/PrintStream.println:(Ljava/lang/String;)V
#18 = Methodref #56.#58 // java/io/PrintStream.println:(I)V
#19 = Class #59 // java/lang/Object
#20 = Utf8 testing
#21 = Utf8 I
#22 = Utf8 <init>
#23 = Utf8 ()V
#24 = Utf8 Code
#25 = Utf8 LineNumberTable
#26 = Utf8 main
#27 = Utf8 ([Ljava/lang/String;)V
#28 = Utf8 testConsumer
#29 = Utf8 testConsumerImpl
#30 = Utf8 (Ljava/util/function/Consumer;)V
#31 = Utf8 Signature
#32 = Utf8 (Ljava/util/function/Consumer<Ljava/lang/Object;>;)V
#33 = Utf8 lambda$testConsumer$0
#34 = Utf8 (LLambdaByteCodeAnalysis3;Ljava/lang/Object;)V
#35 = Utf8 SourceFile
#36 = Utf8 LambdaByteCodeAnalysis3.java
#37 = NameAndType #22:#23 // "<init>":()V
#38 = NameAndType #20:#21 // testing:I
#39 = NameAndType #28:#23 // testConsumer:()V
#40 = Utf8 LambdaByteCodeAnalysis3
#41 = Utf8 BootstrapMethods
#42 = MethodHandle #6:#60 // invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/Stri
ng;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#43 = MethodType #61 // (Ljava/lang/Object;)V
#44 = MethodHandle #6:#62 // invokestatic LambdaByteCodeAnalysis3.lambda$testConsumer$0:(LLambdaByteCodeAnalysis3;Ljava/lang/Object;)V
#45 = NameAndType #63:#64 // accept:(LLambdaByteCodeAnalysis3;)Ljava/util/function/Consumer;
#46 = NameAndType #29:#30 // testConsumerImpl:(Ljava/util/function/Consumer;)V
#47 = Class #65 // java/util/function/Consumer
#48 = NameAndType #63:#61 // accept:(Ljava/lang/Object;)V
#49 = Class #66 // java/lang/System
#50 = NameAndType #67:#68 // out:Ljava/io/PrintStream;
#51 = Utf8 java/lang/StringBuilder
#52 = Utf8 Hello, Mr.
#53 = NameAndType #69:#70 // append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
#54 = NameAndType #69:#71 // append:(Ljava/lang/Object;)Ljava/lang/StringBuilder;
#55 = NameAndType #72:#73 // toString:()Ljava/lang/String;
#56 = Class #74 // java/io/PrintStream
#57 = NameAndType #75:#76 // println:(Ljava/lang/String;)V
#58 = NameAndType #75:#77 // println:(I)V
#59 = Utf8 java/lang/Object
#60 = Methodref #78.#79 // java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang
/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#61 = Utf8 (Ljava/lang/Object;)V
#62 = Methodref #4.#80 // LambdaByteCodeAnalysis3.lambda$testConsumer$0:(LLambdaByteCodeAnalysis3;Ljava/lang/Object;)V
#63 = Utf8 accept
#64 = Utf8 (LLambdaByteCodeAnalysis3;)Ljava/util/function/Consumer;
#65 = Utf8 java/util/function/Consumer
#66 = Utf8 java/lang/System
#67 = Utf8 out
#68 = Utf8 Ljava/io/PrintStream;
#69 = Utf8 append
#70 = Utf8 (Ljava/lang/String;)Ljava/lang/StringBuilder;
#71 = Utf8 (Ljava/lang/Object;)Ljava/lang/StringBuilder;
#72 = Utf8 toString
#73 = Utf8 ()Ljava/lang/String;
#74 = Utf8 java/io/PrintStream
#75 = Utf8 println
#76 = Utf8 (Ljava/lang/String;)V
#77 = Utf8 (I)V
#78 = Class #81 // java/lang/invoke/LambdaMetafactory
#79 = NameAndType #82:#86 // metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invok
e/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#80 = NameAndType #33:#34 // lambda$testConsumer$0:(LLambdaByteCodeAnalysis3;Ljava/lang/Object;)V
#81 = Utf8 java/lang/invoke/LambdaMetafactory
#82 = Utf8 metafactory
#83 = Class #88 // java/lang/invoke/MethodHandles$Lookup
#84 = Utf8 Lookup
#85 = Utf8 InnerClasses
#86 = Utf8 (Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke
/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#87 = Class #89 // java/lang/invoke/MethodHandles
#88 = Utf8 java/lang/invoke/MethodHandles$Lookup
#89 = Utf8 java/lang/invoke/MethodHandles
{
int testing;
descriptor: I
flags:
public LambdaByteCodeAnalysis3();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=2, locals=1, args_size=1
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: aload_0
5: iconst_0
6: putfield #2 // Field testing:I
9: return
LineNumberTable:
line 3: 0
line 5: 4
public static void main(java.lang.String[]);
descriptor: ([Ljava/lang/String;)V
flags: ACC_PUBLIC, ACC_STATIC
Code:
stack=0, locals=1, args_size=1
0: invokestatic #3 // Method testConsumer:()V
3: return
LineNumberTable:
line 8: 0
line 9: 3
}
SourceFile: "LambdaByteCodeAnalysis3.java"
InnerClasses:
public static final #84= #83 of #87; //Lookup=class java/lang/invoke/MethodHandles$Lookup of class java/lang/invoke/MethodHandles
BootstrapMethods:
0: #42 invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljav
a/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
Method arguments:
#43 (Ljava/lang/Object;)V
#44 invokestatic LambdaByteCodeAnalysis3.lambda$testConsumer$0:(LLambdaByteCodeAnalysis3;Ljava/lang/Object;)V
#43 (Ljava/lang/Object;)V
C:\E_Drive\Projects\SourceCode\Learning\learn\src\com\learn\oracle\LearningJavaLang\ClassesAndObject\LamdaExpression>
答案 0 :(得分：2)
Java Language Specification 说：
与出现在匿名类声明中的代码不同，lambda正文中出现的名称以及
this和super关键字的含义以及引用声明的可访问性与周围环境相同上下文（lambda参数引入新名称除外）。lambda表达式主体中的
this（包括显式和隐式）的透明性（即，与周围环境中相同）将为实现提供更大的灵活性，并防止不合格的含义体内的名称不依赖于重载分辨率。实际上，lambda表达式需要谈论自己（以递归方式调用其自身或调用其其他方法）是不寻常的，而更常见的是想使用名称来指代外壳中的事物否则会被遮盖的类（
this，toString()）。如果有必要让lambda表达式引用自身（就像通过this一样），则应改用方法引用或匿名内部类。
答案 1 :(得分：1)
我的回答和简单的逻辑是，由于this用于引用对象的状态，而lambda表达式没有任何状态（也捕获了外部变量访问），所以没有意义this引用了lambda表达式的对象。