🙌🏻 ▫️ 🍦 API para las que vale la pena actualizar finalmente desde Java 8. Parte 3 🛳️ 🎾 ⛈️

¿Cuáles son las razones para migrar a nuevas versiones de Java? Alguien lo hará debido a la nueva lengua características tales como switch

, bloques de texto o registros . Alguien necesitará nuevas características interesantes como módulos o recolectores de basura de pausa baja . Alguien hará esto simplemente porque al actualizar la versión de Java, su programa será más rápido y consumirá menos memoria . Pero hay una razón más, no menos importante. Se trata de nuevas API que le permitirán escribir menos código y evitar perder tiempo buscando la funcionalidad deseada en bibliotecas externas. Y en algunos casos harán que su código sea más rápido.

En las dos partes anteriores, ya hemos cubierto 10 nuevas API que aparecieron en Java 9 y versiones posteriores ( parte 1 , parte 2 ). Hoy veremos 10 más.

uno. `Stream.toList()`

Introducido en: Java 16

¿Cuál es la tarea más utilizada Stream

en Java? Por supuesto, para la transformación de listas: tenemos una lista sobre la que necesitamos realizar algún tipo de transformación y devolver una nueva. Probablemente hayas visto este patrón muchas veces en tu proyecto:

List<T> targetList = sourceList
        .stream()
        //  
        .collect(Collectors.toList());

Esto no quiere decir que collect(Collectors.toList())

sea una construcción muy engorrosa, pero aún así quiero escribir menos código para una operación tan frecuente. Y en Java 16, esto se hizo posible con un nuevo método Stream.toList()

:

List<T> targetList = sourceList
        .stream()
        //  
        .toList();

- toList()

collect(Collectors.toList())

? ? , : toList()

, collect(Collectors.toList())

, , . (, ), collect(Collectors.toList())

toList()

.

Stream.toList()

, ! , Stream.toList()

Stream.toArray()

, , Spliterator

SIZED

. Collectors.toList()

ArrayList

, .

. : , , .. . Stream

, new ArrayList<>(sourceList)

List.copyOf(sourceList)

, :

JMH-

import org.openjdk.jmh.annotations.*;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@State(Scope.Thread)
public class ToList {

    @Param({"10", "100", "1000"})
    private int size;

    private List<Integer> sourceList;

    @Setup
    public void setup() {
        sourceList = IntStream
                .range(0, size)
                .boxed()
                .collect(Collectors.toList());
    }

    @Benchmark
    public List<Integer> newArrayList() {
        return new ArrayList<>(sourceList);
    }

    @Benchmark
    public List<Integer> toList() {
        return sourceList.stream().toList();
    }

    @Benchmark
    public List<Integer> copyOf() {
        return List.copyOf(sourceList);
    }

    @Benchmark
    public List<Integer> collectToList() {
        return sourceList.stream().collect(Collectors.toList());
    }

    @Benchmark
    public List<Integer> collectToUnmodifiableList() {
        return sourceList.stream().collect(Collectors.toUnmodifiableList());
    }
}

OpenJDK 64-Bit Server VM (build 16+36-2231, mixed mode, sharing)
Intel Core i5-9500 3.00GHZ
 : -f 3 -wi 3 -w 5 -i 5 -r 5 -t 6 -jvmArgs -XX:+UseParallelGC

, Stream.toList()

collect(Collectors.toList())

, List.copyOf()

! , List.copyOf()

requireNonNull

, null

-, Stream.toList()

null

. List.copyOf()

, null

, Stream

: Spliterator

, ReferencePipeline

..

, . , filter()

:

JMH-

import org.openjdk.jmh.annotations.*;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@State(Scope.Thread)
public class ToListFilter {

    @Param({"10", "100", "1000"})
    private int size;

    private List<Integer> sourceList;

    @Setup
    public void setup() {
        sourceList = IntStream
                .range(0, size)
                .boxed()
                .collect(Collectors.toList());
    }

    @Benchmark
    public List<Integer> toList() {
        return sourceList.stream().filter(i -> i % 2 == 0).toList();
    }

    @Benchmark
    public List<Integer> newArrayList() {
        var list = new ArrayList<Integer>();
        for (var i : sourceList) {
            if (i % 2 == 0) {
                list.add(i);
            }
        }
        return list;
    }

    @Benchmark
    public List<Integer> collectToList() {
        return sourceList.stream().filter(i -> i % 2 == 0).collect(Collectors.toList());
    }

    @Benchmark
    public List<Integer> collectToUnmodifiableList() {
        return sourceList.stream().filter(i -> i % 2 == 0).collect(Collectors.toUnmodifiableList());
    }
}

OpenJDK 64-Bit Server VM (build 16+36-2231, mixed mode, sharing)
Intel Core i5-9500 3.00GHZ
 : -f 3 -wi 3 -w 5 -i 5 -r 5 -t 6 -jvmArgs -XX:+UseParallelGC

! Stream.toList()

new ArrayList()

. ? , Stream.toArray()

SpinedBuffer

, , ArrayList

. , ( chunk ). SpinedBuffer

, 100 (Integer

0 99):

ArrayList

, 1.5 , , . ArrayList

add()

, SpinedBuffer

, . , , .

: Stream.toList()

, , collect(Collectors.toList())

. ( Collectors.toList()

, downstream Collector

Collector

'). , collect(Collectors.toCollection(ArrayList::new))

.

2. `String`

: `formatted()`

, `stripIndent()`

`translateEscapes()`

: Java 15

Java 15 – , :

String str = """
        ,
        !""";

String str = String.format("""
        ,
        %s!""", user);

, ? . , . String.formatted()

, String.format()

:

String str = """
        ,
        %s!""".formatted(user);

, , , , , -, ( ), -, .

, formatted()

:

String str = ", %s!".formatted(user);

, .

, Java 15 – String.stripIndent()

, . , hello.txt

:

    ,
    !

, stripIndent()

:

String str = Files.readString(Path.of("hello.txt")).stripIndent();
System.out.println(str);

,
!

, – String.translateEscapes()

. : .

, hello.txt:

,\n!

String str = Files.readString(Path.of("hello.txt")).translateEscapes();
System.out.println(str);

,
!

3. `CharSequence.isEmpty()`

, `CharSequence.compare()`

`StringBuilder.compareTo()`

: Java 15 / Java 11

, .

, Java 1.5 , , String

isEmpty()

. length()

:

if (str.length() != 0) {
    ...
}

, Java 1.6 String.isEmpty()

- :

if (!str.isEmpty()) {
    ...
}

, String

– CharSequence

( ), - , (, default

- ). , StringBuilder

length()

:

if (stringBuilder.length() != 0) {
    ...
}

14 - : Java 15, isEmpty()

String

, CharSequence

:

if (!stringBuilder.isEmpty()) {
    ...
}

CharSequence

. equals()

: ? : CharSequence

String

, , .

, Java 11, , CharSequence.compare()

:

if (CharSequence.compare(charSeq1, charSeq2) == 0) {
    ...
}

compare()

, .

Java 11 StringBuilder

Comparable

, StringBuilder

compareTo()

:

if (stringBuilder1.compareTo(stringBuilder2) == 0) {
    ...
}

4. `Collectors.filtering()`

`Collectors.flatMapping()`

: Java 9

Collectors.groupingBy()

? , :

record Movie(String title, String genre, double rating) {
}

, :

Stream<Movie> allMovies = Stream.of(
    new Movie("", "", 7.385),
    new Movie("", "", 7.974),
    new Movie(" 2", "", 8.312),
    new Movie(" ", "", 8.33),
    new Movie(" ", "", 8.619),
    new Movie("", "", 8.363),
    new Movie("", "", 7.699)
);

Map<String, List<Movie>> groups = allMovies.collect(
    Collectors.groupingBy(Movie::genre));

groups.forEach((genre, movies) -> {
    System.out.println(genre + ":");
    movies.forEach(movie ->
        System.out.printf("    %s: %.2f%n", movie.title(), movie.rating()));
});

:
    : 8.36
:
    : 7.39
    : 7.97
     2: 8.31
:
     : 8.33
     : 8.62
:
    : 7.70

, , , , 8. ? , Stream.filter()

:

Map<String, List<Movie>> groups = allMovies
    .filter(movie -> movie.rating() > 8)
    .collect(Collectors.groupingBy(Movie::genre));

:
    : 8.36
:
     2: 8.31
:
     : 8.33
     : 8.62

: , , 8. ? : Java, Collectors.filtering()

:

Map<String, List<Movie>> groups = allMovies.collect(
    Collectors.groupingBy(Movie::genre,
        Collectors.filtering(movie -> movie.rating() > 8,
            Collectors.toList())));

groups.forEach((genre, movies) -> {
    System.out.println(genre + ":");
    if (movies.isEmpty()) {
        System.out.println("    <    8 >");
    } else {
        movies.forEach(movie ->
            System.out.printf("    %s: %.2f%n", movie.title(), movie.rating()));
    }
});

groupingBy()

, :

:
    : 8.36
:
     2: 8.31
:
     : 8.33
     : 8.62
:
    <    8 >

. :

record Movie(String title, String genre, double rating, List<String> actors) {
}

Stream<Movie> allMovies = Stream.of(
    new Movie("", "", 7.385,
        List.of("", "", "")),
    new Movie("", "", 7.974,
        List.of("", "", "")),
    new Movie(" 2", "", 8.312,
        List.of("", "", "", "")),
    new Movie(" ", "", 8.33,
        List.of("", "")),
    new Movie(" ", "", 8.619,
        List.of("", "", "", "")),
    new Movie("", "", 8.363,
        List.of("", "")),
    new Movie("", "", 7.699,
        List.of("", ""))
);

groupingBy()

, Set

? Collectors.mapping()

:

Map<String, Set<List<String>>> groups = allMovies.collect(
    Collectors.groupingBy(Movie::genre,
        Collectors.mapping(Movie::actors, Collectors.toSet())));

, , . ? Collectors.flatMapping()

, , Java 9:

Map<String, Set<String>> groups = allMovies.collect(
    Collectors.groupingBy(Movie::genre,
        Collectors.flatMapping(movie -> movie.actors().stream(),
            Collectors.toSet())));

! , :

5. `StackWalker`

: Java 9

? , ? , :

public final class MyLogger {
    public static void log(String message) {
        System.out.println(message);
    }
}

, , , , log()

. Java 8 StackTraceElement[]

, , Thread.getStackTrace()

:

public static void log(String message) {
    StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
    StackTraceElement stackTraceElement = stackTrace[2];
    String msg = stackTraceElement.getClassName() + "."
               + stackTraceElement.getMethodName() + "("
               + stackTraceElement.getFileName() + ":"
               + stackTraceElement.getLineNumber() + ") "
               + message;
    System.out.println(msg);
}

, . , ( , ), JVM Java-. , . :

@Benchmark
public String stackTrace() {
    StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
    StackTraceElement stackTraceElement = stackTrace[2];
    return stackTraceElement.getClassName() + "."
         + stackTraceElement.getMethodName() + "("
         + stackTraceElement.getFileName() + ":"
         + stackTraceElement.getLineNumber() + ")";
}

OpenJDK 64-Bit Server VM (build 16+36-2231, mixed mode, sharing)
Intel Core i5-9500 3.00GHZ
 : -f 1 -wi 3 -w 3 -i 5 -r 5 -t 6

Benchmark          Mode  Cnt    Score   Error  Units
Stack.stackTrace   avgt    5  103,704 ? 1,123  us/op

104 ! ! ? : StackWalker

, Java 9. .

StackWalker

«» . , StackWalker

StackWalker.getInstance()

. StackWalker

. getInstance()

StackWalker

. .

, StackWalker

, :

forEach()

.
getCallerClass()

, ( RETAIN_CLASS_REFERENCE

).
walk()

, Stream<StackFrame>

T

, T

– . .

. log()

:

public static void log(String message) {
    String msg = StackWalker
        .getInstance()
        .walk((Stream<StackFrame> frames) -> {
            StackFrame frame = frames.skip(2).findFirst().get();
            return frame.getClassName() + "."
                 + frame.getMethodName() + "("
                 + frame.getFileName() + ":"
                 + frame.getLineNumber() + ") "
                 + message;
        });
    System.out.println(msg);
}

StackWalker

:

@Benchmark
public String stackWalker() {
    return StackWalker
        .getInstance()
        .walk(frames -> {
            StackFrame frame = frames.skip(2).findFirst().get();
            return frame.getClassName() + "."
                 + frame.getMethodName() + "("
                 + frame.getFileName() + ":"
                 + frame.getLineNumber() + ")";
        });
}

OpenJDK 64-Bit Server VM (build 16+36-2231, mixed mode, sharing)
Intel Core i5-9500 3.00GHZ
 : -f 1 -wi 3 -w 3 -i 5 -r 5 -t 6

Benchmark          Mode  Cnt    Score   Error  Units
Stack.stackTrace   avgt    5  103,704 ? 1,123  us/op
Stack.stackWalker  avgt    5    2,781 ? 0,156  us/op

37 ! . , 2.8 , , .

StackWalker.walk()

Stream

, : , , -. , «», :

package org.mylogger;

public final class MyLogger {
    public enum Level {
        ERROR, WARN, INFO
    }

    public static void error(String message) {
        log(Level.ERROR, message);
    }

    public static void warn(String message) {
        log(Level.WARN, message);
    }

    public static void info(String message) {
        log(Level.INFO, message);
    }

    public static void log(Level level, String message) {
        ...
    }
}

frames.skip(2)

, log()

, error()

, warn()

, log()

, . – Stream.dropWhile()

:

public static void log(Level level, String message) {
    String msg = StackWalker
        .getInstance()
        .walk((Stream<StackFrame> frames) -> {
            StackFrame frame = frames
                .dropWhile(f -> f.getClassName().startsWith("org.mylogger"))
                .findFirst()
                .get();
            return level + " "
                 + frame.getClassName() + "."
                 + frame.getMethodName() + "("
                 + frame.getFileName() + ":"
                 + frame.getLineNumber() + ") "
                 + message;
        });
    System.out.println(msg);
}

StackWalker

?

, Java 9 . , classpath. – , . , org.example.mylib.internal

, , :

package org.example.mylib.internal;

public final class Handler {
    public static void handle() {
        ...
    }
}

Handler

, . , , ? , StackWalker.getCallerClass()

, :

package org.example.mylib.internal;

public final class Handler {
    public static void handle() {
        if (!StackWalker
            .getInstance(Option.RETAIN_CLASS_REFERENCE)
            .getCallerClass()
            .getPackageName()
            .startsWith("org.example.mylib.")) {
            throw new RuntimeException("Security error");
        }
        ...
    }
}

RETAIN_CLASS_REFERENCE

, Class . , Stream.walk()

, getCallerClass()

.

6. `System.Logger`

: Java 9

, API , Java 9. API : System.Logger

, System.LoggerFinder

System.Logger.Level

.

System.Logger

:

public final class Main {
    private static final Logger LOGGER = System.getLogger("");

    public static void main(String[] args)  {
        LOGGER.log(Level.ERROR, "Critical error!");
    }
}

. 17, 2021 6:24:57 PM org.example.Main main
SEVERE: Critical error!

System.Logger

– , , . , : , SLF4J – , Logback. Log4j API – Log4j Core. , System.Logger

– java.util.logging

, java.logging

.

SLF4J , , Log4j java.util.logging

. Log4j API SLF4J java.util.logging

. System.Logger

: , . java.util.logging

, - . , Log4j, :

<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-api</artifactId>
    <version>2.14.1</version> <!--       -->
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.14.1</version>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-jpl</artifactId>
    <version>2.14.1</version>
    <scope>runtime</scope>
</dependency>

: , log4j-jpl

classpath, . Java ServiceLoader

LoggerFinder

Log4jSystemLoggerFinder

Log4j:

18:24:57.941 [main] ERROR  - Critical error!

java.logging

JRE/JDK, ( java.util.logging

).

, System.Logger

SLF4J/Logback . – , SLF4J . GitHub . Log4j – .

System.Logger

:

LOGGER.log(Level.INFO, "Information");
LOGGER.log(Level.DEBUG, "Sum of {} and {} is {}:", 2, 3, 2+3);
LOGGER.log(Level.TRACE, () -> "Lazy message");
LOGGER.log(Level.ERROR, "Log exception", new Exception());

7. `Lookup.defineHiddenClass()`

: Java 15

MethodHandles.Lookup.defineClass()

, , . , : , , ( ). , . Java 15 , .

Lookup.defineHiddenClass()

. Unsafe.defineAnonymousClass()

, , . Unsafe.defineAnonymousClass()

Java 15 deprecated for removal.

. .
. , ( Class.forName()

, ClassLoader.loadClass()

, ClassLoader.findLoadedClass()

..). - < ->/<suffix>

(, org.example.Temp/0x0000000800cb8000

).
, , , Class

( , , ClassOption.STRONG

defineHiddenClass()

).
, -XX:+UnlockDiagnosticVMOptions -XX:+ShowHiddenFrames

.

, , . :

jshell> Runnable runnable = () -> {}
runnable ==> $Lambda$26/0x0000000800c0aa00@443b7951

jshell> runnable.getClass().isHidden()
$2 ==> true

« ». int

'. javac, ByteBuddy.

- :

byte[] bytes = new ByteBuddy()
        .subclass(Object.class)
        .name("org.example.Temp")
        .defineMethod("sum", int.class, Modifier.PUBLIC)
        .withParameters(int.class, int.class)
        .intercept(new Implementation.Simple(
                MethodVariableAccess.INTEGER.loadFrom(1),
                MethodVariableAccess.INTEGER.loadFrom(2),
                Addition.INTEGER,
                MethodReturn.INTEGER))
        .make()
        .getBytes();

, -:

package org.example;
public class Temp {
    public int sum(int x, int y) {
        return x + y;
    }
}

, - , - :

Lookup lookup = MethodHandles
        .lookup()
        .defineHiddenClass(bytes, false);

//     MethodHandle  reflection
Object obj = lookup
        .findConstructor(lookup.lookupClass(), MethodType.methodType(void.class))
        .invoke();

MethodHandle sumHandle = lookup.findVirtual(lookup.lookupClass(), "sum",
        MethodType.methodType(int.class, int.class, int.class));

//   sum.   5
System.out.println(sumHandle.invoke(obj, 3, 2));

, , . :

Lookup lookup1 = MethodHandles.lookup().defineHiddenClass(bytes, false);
Lookup lookup2 = MethodHandles.lookup().defineHiddenClass(bytes, false);
Lookup lookup3 = MethodHandles.lookup().defineHiddenClass(bytes, false);
System.out.println(lookup1.lookupClass()); // class org.example.Temp/0x0000000800cb4000
System.out.println(lookup2.lookupClass()); // class org.example.Temp/0x0000000800cb4400
System.out.println(lookup3.lookupClass()); // class org.example.Temp/0x0000000800cb4800

8. `Math`

: Java 9 / Java 15

, , Java, :

int x = ...
int y = ...
long z = x * y;

Java, : int

– int

, , z

long

, . long

:

long z = (long) x * y;

, - . -, , , . -, , , . , . :

  int     long

Java 9 . Math.multiplyFull()

:

long z = Math.multiplyFull(x, y);

Java , , Java 8 Math

:

int toIntExact(long value)
int incrementExact(int a)
long incrementExact(long a)
int decrementExact(int a)
long decrementExact(long a)
int negateExact(int a)
long negateExact(long a)
int addExact(int x, int y)
long addExact(long x, long y)
int subtractExact(int x, int y)
long subtractExact(long x, long y)
int multiplyExact(int x, int y)
long multiplyExact(long x, long y)

, , – , - . ? , . , , , :

jshell> Math.abs(Integer.MIN_VALUE)
$1 ==> -2147483648

, – ? , , 2147483648 int

, . , Math.absExact()

, Java 15:

jshell> Math.absExact(Integer.MIN_VALUE)
|  Exception java.lang.ArithmeticException: Overflow to represent absolute value of Integer.MIN_VALUE
|        at Math.absExact (Math.java:1392)
|        at (#1:1)

jshell> Math.absExact(Long.MIN_VALUE)
|  Exception java.lang.ArithmeticException: Overflow to represent absolute value of Long.MIN_VALUE
|        at Math.absExact (Math.java:1438)
|        at (#2:1)

, , -11 3? ? :

jshell> -11 / 3
$1 ==> -3

jshell> -11 % 3
$2 ==> -2

, -11 = 3 * (-3) - 2

. , , Python, :

>>> -11 / 3
-4
>>> -11 % 3
1

- : -11 = 3 * (-4) + 1

. , : . Java , Python – . , Java -? Java 9 Math.floorDiv()

Math.floorMod()

:

jshell> Math.floorDiv(-11, 3)
$1 ==> -4

jshell> Math.floorMod(-11, 3)
$2 ==> 1

Java 9 Math.fma(float, float, float)

Math.fma(double, double, double)

, , a * b + c

, , :

jshell> Math.fma(2.99, 5.91, 7.1)
$1 ==> 24.7709

jshell> 2.99 * 5.91 + 7.1
$2 ==> 24.770900000000005

9. `java.io.Serial`

: Java 14

Java? , , Java-. :

public class Point {
    private static final long serialVersionUID = 1L;

    public int x;
    public int y;
}

Point

, :

var point = new Point();
point.x = 1;
point.y = 2;

var baos = new ByteArrayOutputStream();
try (var oos = new ObjectOutputStream(baos)) {
    oos.writeObject(point);
}
byte[] bytes = baos.toByteArray();

. , ? , Serializable

! ( serialVersionUID

, .)

public class Point implements Serializable {
    private static final long serialVersionUID = 1;

    public int x;
    public int y;
}

– : Serializable

, serialVersionUID

, .. , Java 14 Serial

.

, :

public class Point implements Serializable {
    @Serial
    private static final long serialVersionUID = 1;
    ...
}

, , :

public class Point {
    @Serial // Annotated member is not a part of the serialization mechanism
    private static final long serialVersionUID = 1;
    ...
}

public class Point implements Serializable {
    @Serial // Annotated member is not a part of the serialization mechanism
    private static final int serialVersionUID = 1;
    ...
}

, : serialVersionUID

, serialPersistentFields

, writeObject()

, readObject()

..

, IntelliJ IDEA. JDK 16 -Xlint:serial

. , javac

:

> javac -Xlint:serial Point.java
Point.java:6: warning: [serial] serialVersionUID must be of type long in class Point
    private static final int serialVersionUID = 1;
                             ^

, Java 17.

10. `Objects`

: `checkIndex()`

, `checkFromIndexSize()`

, `checkFromToIndex()`

: Java 9 / Java 16

, , , , . :

private static void getAt(int index, int length) {
    if (index < 0) {
        throw new IllegalArgumentException("index < 0");
    }
    if (index >= length) {
        throw new IllegalArgumentException("index >= length");
    }
    ...
}

, , :

public final class PreconditionUtils {
    public static void checkIndex(int index, int length) {
        if (index < 0) {
            throw new IllegalArgumentException("index < 0");
        }
        if (index >= length) {
            throw new IllegalArgumentException("index >= length");
        }
    }
}

Java 9 , Objects

.

Objects.checkIndex()

, [0, length)

:

jshell> Objects.checkIndex(-3, 10)
|  Exception java.lang.IndexOutOfBoundsException: Index -3 out of bounds for length 10
|        at Preconditions.outOfBounds (Preconditions.java:64)
|        at Preconditions.outOfBoundsCheckIndex (Preconditions.java:70)
|        at Preconditions.checkIndex (Preconditions.java:248)
|        at Objects.checkIndex (Objects.java:372)
|        at (#1:1)

jshell> Objects.checkIndex(10, 10)
|  Exception java.lang.IndexOutOfBoundsException: Index 10 out of bounds for length 10
|        at Preconditions.outOfBounds (Preconditions.java:64)
|        at Preconditions.outOfBoundsCheckIndex (Preconditions.java:70)
|        at Preconditions.checkIndex (Preconditions.java:248)
|        at Objects.checkIndex (Objects.java:372)
|        at (#2:1)

Objects.checkFromIndexSize()

, [fromIndex, fromIndex + size)

[0, length)

:

jshell> Objects.checkFromIndexSize(3, 8, 10)
|  Exception java.lang.IndexOutOfBoundsException: Range [3, 3 + 8) out of bounds for length 10
|        at Preconditions.outOfBounds (Preconditions.java:64)
|        at Preconditions.outOfBoundsCheckFromIndexSize (Preconditions.java:82)
|        at Preconditions.checkFromIndexSize (Preconditions.java:343)
|        at Objects.checkFromIndexSize (Objects.java:424)
|        at (#3:1)

jshell> Objects.checkFromIndexSize(-2, 8, 10)
|  Exception java.lang.IndexOutOfBoundsException: Range [-2, -2 + 8) out of bounds for length 10
|        at Preconditions.outOfBounds (Preconditions.java:64)
|        at Preconditions.outOfBoundsCheckFromIndexSize (Preconditions.java:82)
|        at Preconditions.checkFromIndexSize (Preconditions.java:343)
|        at Objects.checkFromIndexSize (Objects.java:424)
|        at (#4:1)

jshell> Objects.checkFromIndexSize(3, -4, 10)
|  Exception java.lang.IndexOutOfBoundsException: Range [3, 3 + -4) out of bounds for length 10
|        at Preconditions.outOfBounds (Preconditions.java:64)
|        at Preconditions.outOfBoundsCheckFromIndexSize (Preconditions.java:82)
|        at Preconditions.checkFromIndexSize (Preconditions.java:343)
|        at Objects.checkFromIndexSize (Objects.java:424)
|        at (#5:1)

, Objects.checkFromToIndex()

, [fromIndex, toIndex)

[0, length)

:

jshell> Objects.checkFromToIndex(3, 11, 10)
|  Exception java.lang.IndexOutOfBoundsException: Range [3, 11) out of bounds for length 10
|        at Preconditions.outOfBounds (Preconditions.java:64)
|        at Preconditions.outOfBoundsCheckFromToIndex (Preconditions.java:76)
|        at Preconditions.checkFromToIndex (Preconditions.java:295)
|        at Objects.checkFromToIndex (Objects.java:398)
|        at (#6:1)

jshell> Objects.checkFromToIndex(-4, 8, 10)
|  Exception java.lang.IndexOutOfBoundsException: Range [-4, 8) out of bounds for length 10
|        at Preconditions.outOfBounds (Preconditions.java:64)
|        at Preconditions.outOfBoundsCheckFromToIndex (Preconditions.java:76)
|        at Preconditions.checkFromToIndex (Preconditions.java:295)
|        at Objects.checkFromToIndex (Objects.java:398)
|        at (#7:1)

jshell> Objects.checkFromToIndex(6, 4, 10)
|  Exception java.lang.IndexOutOfBoundsException: Range [6, 4) out of bounds for length 10
|        at Preconditions.outOfBounds (Preconditions.java:64)
|        at Preconditions.outOfBoundsCheckFromToIndex (Preconditions.java:76)
|        at Preconditions.checkFromToIndex (Preconditions.java:295)
|        at Objects.checkFromToIndex (Objects.java:398)
|        at (#8:1)

, Java 16 long

:

10 API, Java 16, 9- . , Java. , Java , , (1, 2, 3, 4, 5, 6, 7, 8). Java 8 , .

...

API para las que vale la pena actualizar finalmente desde Java 8. Parte 3

uno. Stream.toList() (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

Introducido en: Java 16

: Java 15

: Java 15 / Java 11

: Java 9

5. StackWalker (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

: Java 9

6. System.Logger (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

: Java 9

7. Lookup.defineHiddenClass() (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

: Java 15

8. Math (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

: Java 9 / Java 15

9. java.io.Serial (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

: Java 14

: Java 9 / Java 16

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uno. `Stream.toList()`

5. `StackWalker`

6. `System.Logger`

7. `Lookup.defineHiddenClass()`

8. `Math`

9. `java.io.Serial`