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mkyongmkyong
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jep138
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5 files changed

+108
-32
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‎java-11/src/main/java/com/mkyong/java11/Main.java‎

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@@ -1,37 +1,7 @@
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package com.mkyong.java11;
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import java.nio.charset.StandardCharsets;
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import java.security.*;
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import java.security.spec.InvalidKeySpecException;
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import java.security.spec.NamedParameterSpec;
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import java.security.spec.PKCS8EncodedKeySpec;
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import java.security.spec.X509EncodedKeySpec;
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import java.util.Base64;
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public class Main {
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public static void main(String[] args) throws NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeySpecException {
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KeyPairGenerator kpg = KeyPairGenerator.getInstance("XDH");
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NamedParameterSpec paramSpec = new NamedParameterSpec("X25519");
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kpg.initialize(paramSpec); // equivalent to kpg.initialize(255)
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// alternatively: kpg = KeyPairGenerator.getInstance("X25519")
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KeyPair kp = kpg.generateKeyPair();
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/*KeyPairGenerator kpg = KeyPairGenerator.getInstance("X25519");
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KeyPair kp = kpg.generateKeyPair();
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PublicKey publicKey = kp.getPublic();
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System.out.println(publicKey.getAlgorithm());
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System.out.println(publicKey.getFormat());
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System.out.println(new String(publicKey.getEncoded(), StandardCharsets.UTF_8));
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PrivateKey privateKey = kp.getPrivate();
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System.out.println(privateKey.getAlgorithm());
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System.out.println(privateKey.getFormat());*/
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public static void main(String[] args) {
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System.out.println("Hello Java 11");
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}
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}

‎java-11/src/main/java/com/mkyong/java11/jep327/PrintUnicode.java‎

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package com.mkyong.java11.jep327;
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public class PrintUnicode {
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public static void main(String[] args) {
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String codepoint = "U+1F92A";
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System.out.println(convertCodePoints(codepoint));
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}
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// Java, UTF-16
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// Convert code point to unicode
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static char[] convertCodePoints(String codePoint) {
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Integer i = Integer.valueOf(codePoint.substring(2), 16);
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char[] chars = Character.toChars(i);
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return chars;
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}
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}

‎java-11/src/main/java/com/mkyong/java11/jep327/PrintUnicode2.java‎

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package com.mkyong.java11.jep327;
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// https://stackoverflow.com/questions/18380901/how-do-i-convert-unicode-codepoints-to-their-character-representation
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public class PrintUnicode2 {
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public static void main(String[] args) {
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printCodePoints("U+0041"); // Latin capital A
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printCodePoints("U+20BF"); // Bitcoin icon = ₿
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printCodePoints("U+32C0"); // January in Chinese = ㋀
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printCodePoints("U+1F929"); // emoji 🤩
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printCodePoints("U+4F60");
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// convert Unicode code points
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//String codePoints = "U+20BF"; // Bitcoin icon = ₿
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String codePoints = "U+1F929"; // Bitcoin icon = ₿
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Integer i = Integer.valueOf(codePoints.substring(2), 16);
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System.out.println(i); // 8383
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// Unicode in UTF-16 encoding
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char[] unicode16 = Character.toChars(i);
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System.out.println(unicode16);
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String s = Character.toString(i);
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// convert Unicode in UTF-16 to Unicode code points
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if(Character.isBmpCodePoint(i)){
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String hex = Integer.toHexString(i);
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System.out.println(String.format("U+%S", hex));
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}else{
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// Supplementary code point
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int supCodePoints = Character.toCodePoint(unicode16[0], unicode16[1]);
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String hex = Integer.toHexString(supCodePoints);
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System.out.println(String.format("U+%S", hex));
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}
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}
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static void printCodePoints(String codePoint) {
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Integer i = Integer.valueOf(codePoint.substring(2), 16);
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char[] chars = Character.toChars(i);
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System.out.println(chars);
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}
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}

‎java-11/src/main/java/com/mkyong/java11/jep328/MemoryLeak.java‎

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package com.mkyong.java11.jep328;
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import java.util.concurrent.*;
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public class MemoryLeak {
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private static BlockingQueue<byte[]> queue = new LinkedBlockingQueue<>(10);
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public static void main(String[] args) {
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Runnable producer = () -> {
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while (true) {
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// generates 1mb of object every 10ms
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queue.offer(new byte[1 * 1024 * 1024]);
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try {
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TimeUnit.MILLISECONDS.sleep(10);
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} catch (InterruptedException e) {
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e.printStackTrace();
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}
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}
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};
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Runnable consumer = () -> {
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while (true) {
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try {
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// process every 100ms
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queue.take();
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TimeUnit.MILLISECONDS.sleep(100);
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} catch (InterruptedException e) {
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e.printStackTrace();
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}
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}
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};
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// give a name, good for profiling
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new Thread(producer, "Producer Thread").start();
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new Thread(consumer, "Consumer Thread").start();
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}
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}

‎java-11/src/main/resources/jep328/leak.jfr‎

3.2 MB
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