Stream中findAny

ReferencePipeline$Head@967的ReferencePipeline的forEachWithCancel方法传入ReferencePipeline$2$1@999 filter的spliterator font color=\"#f44336\

ReferencePipeline$3@978的AbstractPipeline的 wrapSinksink FindOps$FindSink$OfRef@995final <P_IN> Sink<P_IN> wrapSink(Sink<E_OUT> sink) {        Objects.requireNonNull(sink);        for ( @SuppressWarnings(\"rawtypes\") AbstractPipeline p=AbstractPipeline.this; p.depth > 0; p=p.previousStage) {// p指向上一阶段            sink = p.font color=\"#2196f3\

注意：因为一级一级向前调用操作符，所以当第一个操作符即filter为true的时候就会返回，之后的数据都不会匹配，也就是说findAny方法总是获取到的是filter第一个匹配的值，因此可能不会遍历完整个数组，短路操作

AbstractPipeline 方法 evaluateterminalOp地址  font color=\"#f44336\

调ReferencePipeline$3@978的AbstractPipeline 的copyInto方法传入ReferencePipeline$2$1@999 filter的spliterator font color=\"#f44336\

调ReferencePipeline$3@978的AbstractPipeline 的copyIntoWithCancel方法传入ReferencePipeline$2$1@999 filter的spliterator font color=\"#f44336\

Stream<String> stream2 = stream1.map(author -> author.getName());// stream2 ReferencePipeline$3@978// 类$lambda@977Optional<String> stream2Any = stream2.findAny();// Optional@1037

调用AbstractPipeline抽象类的evaluate方法，和filter调用的方法一样

调findAny（）

font color=\"#f44336\

List<Author> authorList = getAuthors();Stream<Author> stream = authorList.stream();Stream<Author> stream1 = stream.filter(author -> author.getAge() > 10);long count = stream1.count();Stream<String> stream2 = stream1.map(author -> author.getName());Optional<String> stream2Any = stream2.findAny();String name = stream2Any.orElseGet(() -> \"佚名\");System.out.println(count);System.out.println(name);// 错误用法

第一次map的opWrapSink

分别调用map ReferencePipeline$3$1@998的cancellationRequestedpublic boolean cancellationRequested() {            return downstream.cancellationRequested();        }downstream findAny FindOps$FindSink$OfRef@995

List<Author> authorList = getAuthors();//ArrayList@725，分割迭代器对象ArrayList$ArrayListSpliterator@960Stream<Author> stream = authorList.stream();// ReferencePipeline$Head@967//类名$lambda@972Stream<Author> stream1 = stream.filter(author -> author.getAge() > 10);// stream1 ReferencePipeline$2@973

分别调用filterReferencePipeline$2$1@999的cancellationRequestedpublic boolean cancellationRequested() {            return downstream.cancellationRequested();        }downstream map ReferencePipeline$3$1@998

new FindOp

helper调ReferencePipeline$3@978的AbstractPipeline 的wrapAndCopyInto方法sink FindOps$FindSink$OfRef@995spliterator font color=\"#f44336\

调ReferencePipeline抽象类的map方法new StatelessOp() stream2 ReferencePipeline$3@978

匿名对象  类$lambda@1159String name = stream2Any.orElseGet(() -> \"佚名\");System.out.println(name);

ArrayList终态内部类ArrayListSpliteratorthis ArrayList$ArrayListSpliterator@960传入ReferencePipeline$2$1@999public boolean font color=\"#0097a7\

看同个流中间操作

public ChainedReference(Sink<? super E_OUT> downstream) {            this.downstream = Objects.requireNonNull(downstream);        }downstream地址ReferencePipeline$3$1@998

调FindOps类中FindSink内部静态抽象类OfRef中的静态属性font color=\"#388e3c\

List<Author> authorList = getAuthors();Stream<Author> stream = authorList.stream();Stream<Author> stream1 = stream.filter(author -> author.getAge() > 10);Stream<String> stream2 = stream1.map(author -> author.getName());Optional<String> stream2Any = stream2.findAny();String name = stream2Any.orElseGet(() -> \"佚名\");System.out.println(name);

第二次filter的opWrapSink

Optional类的orElseGetpublic T orElseGet(Supplier<? extends T> supplier) {        return value != null ? value : supplier.get();    }

public ChainedReference(Sink<? super E_OUT> downstream) {            this.downstream = Objects.requireNonNull(downstream);        }downstream地址FindOps$FindSink$OfRef@995

new FindOps中私有静态终态内部类FindOp实现font color=\"#388e3c\

Optional::isPresentnew Predicate匿名内部类实现test方法，返回判断接口的isPresent()new Predicate<Optional<Object>>() {@Overridepublic boolean test(Optional<Object> o) {return o.isPresent();}}FindOps$FindSink$OfRef$lambda@981

do { } while (!(cancelled = sink.cancellationRequested()) && spliterator.font color=\"#0097a7\

downstream.accept(mapper.apply(u));mapper地址map(lambda表达式地址返回name)类$lambda@977在调用downstream FindOps$FindSink$OfRef@995的accept即FindOps类的私有抽象静态类FindSink的public void accept(T value) {            if (!hasValue) {                hasValue = true;// 对hasValue设置为true，避免forEachWithCancelfont color=\"#212121\

List<Author> authorList = getAuthors();//font color=\"#f44336\

FindOps类的私有抽象静态类的FindSinkpublic boolean cancellationRequested() {            return hasValue;// 构建findAny的时候初始默认值 false        }

调ReferencePipeline抽象类的findAny()public final Optional<P_OUT> findAny() {        return evaluate(FindOps.makeRef(false));    }FindOps.makeRef(false)地址FindOps$FindOp@979

mustFindFirst=false

ReferencePipeline$3$1@998指向的是ReferencePipeline的map的opWrapSink()的new Sink.ChainedReference匿名内部类的public void accept(P_OUT u) {downstream.accept(mapper.apply(u));}downstream FindOps$FindSink$OfRef@995

由于和filter一样这里就不赘述了，写生成的类记录有区别的地方

Stream<String> stream2 = stream1.map(author -> author.getName());Optional<String> stream2Any = stream2.findAny();String name = stream2Any.orElseGet(() -> \"佚名\");

Stream<String> stream2 = stream1.map(author -> author.getName());

调FindOps类的静态方法makeRefmustFindFirst=falsefont color=\"#f44336\

ReferencePipeline$2$1@999指向的是ReferencePipeline的filter的opWrapSink()的new Sink.ChainedReference匿名内部类的public void accept(P_OUT u) {if (predicate.test(u))downstream.accept(u);}downstream ReferencePipeline$3$1@998