---
title: Java 24
description: JDK 24 Java
category: Java
tag:
- Java
head:
- - meta
- name: keywords
content: Java 24,JDK24,JEP ,,GC ,
---
JDK 24 2025 3 LTS 2025 9 LTS **JDK 25**
JDK 24 24
- [JEP 478: Key Derivation Function API ( API, )](https://openjdk.org/jeps/478)
- [JEP 483: Early Class-File Loading & Linking ()](https://openjdk.org/jeps/483)
- [JEP 484: Class File API ( API)](https://openjdk.org/jeps/484)
- [JEP 485: Stream Gatherers ()](https://openjdk.org/jeps/485)
- [JEP 486: Disable the Security Manager ()](https://openjdk.org/jeps/486)
- [JEP 487: Scoped Values (, )](https://openjdk.org/jeps/487)
- [JEP 495: Simplified Source Files and Instance Main Methods (, )](https://openjdk.org/jeps/495)
- [JEP 497: Quantum-Resistant Digital Signature Algorithm (ML-DSA) ()](https://openjdk.org/jeps/497)
- [JEP 499: Structured Concurrency (, )](https://openjdk.org/jeps/499)
JDK 8 JDK 25
## JEP 478: Key Derivation Function API API
API API JDK 24
API HKDF
```java
// KDF HKDF-SHA256
KDF hkdf = KDF.getInstance("HKDF-SHA256");
// Extract Expand
AlgorithmParameterSpec params =
HKDFParameterSpec.ofExtract()
.addIKM(initialKeyMaterial) //
.addSalt(salt) //
.thenExpand(info, 32); //
// 32 AES
SecretKey key = hkdf.deriveKey("AES", params);
// KDF
```
## JEP 483: Early Class-File Loading & Linking
JVM JEP 483 Spring PetClinic AOT 42%
AOT `-XX:AOTMode=record``-XX:AOTConfiguration``-XX:AOTMode=create` `-XX:AOTCache`
## JEP 484: Class File API API
API JDK 22 [JEP 457](https://openjdk.org/jeps/457) JDK 23 [JEP 466](https://openjdk.org/jeps/466) JDK 24
API API Java ASM
```java
// ClassFile
ClassFile cf = ClassFile.of();
// ClassModel
ClassModel classModel = cf.parse(bytes);
// "debug"
byte[] newBytes = cf.build(classModel.thisClass().asSymbol(),
classBuilder -> {
//
for (ClassElement ce : classModel) {
// "debug"
if (!(ce instanceof MethodModel mm
&& mm.methodName().stringValue().startsWith("debug"))) {
//
classBuilder.with(ce);
}
}
});
```
## JEP 485: Stream Gatherers
`Stream::gather(Gatherer)` `Gatherer`
`filter``map` `distinct` `Stream::gather` Stream `Stream::gather` Stream API
`Stream::gather(Gatherer)`
```java
var result = Stream.of("foo", "bar", "baz", "quux")
.gather(Gatherer.ofSequential(
HashSet::new, // HashSet,
(set, str, downstream) -> {
if (set.add(str.length())) {
return downstream.push(str);
}
return true; //
}
))
.toList();//
// ==> [foo, quux]
```
## JEP 486: Disable the Security Manager
JDK 24 `Security Manager` `java -Djava.security.manager` `Security Manager` Java Java
## JEP 487: Scoped Values,
Scoped Values
```java
final static ScopedValue V = ScopedValue.newInstance();
// In some method
ScopedValue.where(V, )
.run(() -> { ... V.get() ... call methods ... });
// In a method called directly or indirectly from the lambda expression
... V.get() ...
```
## JEP 491: Virtual Threads Synchronization Without Pinning
`synchronized` `synchronized` (Pinning)
`synchronized` Java I/O `synchronized`
## JEP 493: Linking Run-Time Images Without JMOD Files JMOD
JDK JMOD jlink JDK JMOD JDK 25%
- Jlink Java 9 Java JRE
- JMOD
## JEP 495: Simplified Source Files and Instance Main Methods,
`main` Java `main` Java
`main`
```java
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}
```
`main`
```java
class HelloWorld {
void main() {
System.out.println("Hello, World!");
}
}
```
```java
void main() {
System.out.println("Hello, World!");
}
```
## JEP 497: Quantum-Resistant Digital Signature Algorithm (ML-DSA)
JDK 24 Module-Lattice-Based Digital Signature Algorithm, **ML-DSA**
ML-DSA NIST FIPS 204
## JEP 498: Warnings When Using `sun.misc.Unsafe` Memory Access Methods ( `sun.misc.Unsafe` )
JDK 23([JEP 471](https://openjdk.org/jeps/471)) `sun.misc.Unsafe` JDK 24 `sun.misc.Unsafe`
- `java.lang.invoke.VarHandle`JDK 9 (JEP 193)
- `java.lang.foreign.MemorySegment`JDK 22 (JEP 454) `VarHandle`
`MemorySegment` Foreign Function & Memory API API`VarHandle` APIForeign Function & Memory API JDK 22
```java
import java.lang.foreign.*;
import java.lang.invoke.VarHandle;
//
class OffHeapIntBuffer {
// VarHandle
private static final VarHandle ELEM_VH = ValueLayout.JAVA_INT.arrayElementVarHandle();
//
private final Arena arena;
//
private final MemorySegment buffer;
//
public OffHeapIntBuffer(long size) {
this.arena = Arena.ofShared();
this.buffer = arena.allocate(ValueLayout.JAVA_INT, size);
}
//
public void deallocate() {
arena.close();
}
// volatile
public void setVolatile(long index, int value) {
ELEM_VH.setVolatile(buffer, 0L, index, value);
}
// 0
public void initialize(long start, long n) {
buffer.asSlice(ValueLayout.JAVA_INT.byteSize() * start,
ValueLayout.JAVA_INT.byteSize() * n)
.fill((byte) 0);
}
//
public int[] copyToNewArray(long start, int n) {
return buffer.asSlice(ValueLayout.JAVA_INT.byteSize() * start,
ValueLayout.JAVA_INT.byteSize() * n)
.toArray(ValueLayout.JAVA_INT);
}
}
```
## JEP 499: Structured Concurrency,
JDK 19 API JDK 24 API `java.util.concurrent`
API `StructuredTaskScope`
`StructuredTaskScope`
```java
try (var scope = new StructuredTaskScope()) {
// fork
Subtask subtask1 = scope.fork(task1);
Subtask subtask2 = scope.fork(task2);
//
scope.join();
//
... process results/exceptions ...
} // close
```
JDK