如何将其转换为流表达式？（使用原子引用）

Question

我需要更改以下代码：

protected void checkNoDuplicateLabels( List<CompileResult> compileResult ) {

    Set<Label> infos = new HashSet<>();

    for ( AbstractTypeInfo info : infoRepo.getList() ) {

        if ( info instanceof Label ) {

            Label label = (Label) info;

            if ( infos.contains( label ) ) {

                compileResult.add( new CompileResult( Severity.FATAL, MessageFormat.format( "Duplicate label found! \n Type: '{0}' \n Language: '{1}'", label.getType(), label.getLanguage() ) ) );

            }

            infos.add( label );

        }

    }

}

成一条溪流。我知道将 Sets 与流一起使用的一种方法是实现 AtomicReferences，它将方法的第一行替换为：

AtomicReference<Set<Label>> infos = new AtomicReference<>( new HashSet<Label>() );

我怎样才能实现循环现在对流执行的相同功能？

Answer 1

你可以不这样做AtomicReference：BinaryOperator<Label> logDuplicate = (label1, label2) -> {&nbsp; &nbsp; // Log label2 as duplicate&nbsp; &nbsp; compileResult.add(new CompileResult(Severity.FATAL, MessageFormat.format("Duplicate label found! \n Type: '{0}' \n Language: '{1}'", label2.getType(), label2.getLanguage())));&nbsp; &nbsp; return label1;};Set<Label> infos = infoRepo.getList()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;.stream()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;.filter(Label.class::isInstance)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;.map(Label.class::cast)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;.collect(toMap(identity(), identity(), logDuplicate, HashMap::new))&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;.keySet();更新：import static java.util.stream.Collectors.toMap;import static java.util.function.Function.identity;