Merge branch 'eugenp:master' into master

Author: wynnteo

core-java-modules/core-java-25/stringbuilder/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.example</groupId>
+    <artifactId>stringbuilder</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+    </properties>
+
+</project>

core-java-modules/core-java-25/stringbuilder/src/main/java/com/example/BufferedReaderApproach.java

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+package com.example;
+
+import java.io.BufferedReader;
+import java.io.StringReader;
+import java.io.IOException;
+
+public class BufferedReaderApproach {
+
+    public static void main(String[] args) {
+
+        StringBuilder sb = new StringBuilder(
+            "StringBuilder\nBufferedReader Approach\r\nLine by Line Reading\rAnother line"
+        );
+
+        try (BufferedReader reader = new BufferedReader(new StringReader(sb.toString()))) {
+
+            String line;
+            while ((line = reader.readLine()) != null) {
+                System.out.println(line);
+            }
+
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+    }
+
+}

core-java-modules/core-java-25/stringbuilder/src/main/java/com/example/LineSeparatorApproach.java

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+package com.example;
+
+public class LineSeparatorApproach {
+    public static void main(String[] args) {
+        StringBuilder sb = new StringBuilder(
+            "StringBuilder\nLine Separator Approach\r\nLine by Line Reading\rAnother line"
+        );
+
+        // \R matches any line break (\n, \r\n, \r)
+        String[] lines = sb.toString().split("\\R");
+
+        for (String line : lines) {
+            System.out.println(line);
+        }
+    }
+}

core-java-modules/core-java-25/stringbuilder/src/main/java/com/example/Main.java

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+package com.example;
+
+public class Main {
+    public static void main(String[] args) {
+
+      
+
+    }
+}

core-java-modules/core-java-25/stringbuilder/src/main/java/com/example/ManualIterationApproach.java

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+package com.example;
+
+public class ManualIterationApproach {
+
+    public static void main(String[] args) {
+
+        StringBuilder sb = new StringBuilder(
+            "StringBuilder\nManual Iteration Approach\r\nLine by Line Reading\rAnother line"
+        );
+
+        int start = 0;
+
+        for (int i = 0; i < sb.length(); i++) {
+
+            char c = sb.charAt(i);
+
+            if (c == '\n' || c == '\r') {
+
+                System.out.println(sb.substring(start, i));
+
+                if (c == '\r' && i + 1 < sb.length() && sb.charAt(i + 1) == '\n') {
+                    i++;
+                }
+
+                start = i + 1;
+            }
+        }
+
+        if (start < sb.length()) {
+            System.out.println(sb.substring(start));
+        }
+    }
+}

core-java-modules/core-java-25/stringbuilder/src/main/java/com/example/ScannerApproach.java

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+package com.example;
+
+import java.util.Scanner;
+import java.io.StringReader;
+
+public class ScannerApproach {
+
+    public static void main(String[] args) {
+
+        StringBuilder sb = new StringBuilder(
+            "StringBuilder\nScanner Approach\r\nLine by Line Reading\rAnother line"
+        );
+
+        Scanner scanner = new Scanner(new StringReader(sb.toString()));
+
+        while (scanner.hasNextLine()) {
+            System.out.println(scanner.nextLine());
+        }
+
+        scanner.close();
+    }
+
+}

core-java-modules/core-java-25/stringbuilder/src/main/java/com/example/StreamLinesApproach.java

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+package com.example;
+
+public class StreamLinesApproach {
+
+    public static void main(String[] args) {
+
+        StringBuilder sb = new StringBuilder(
+            "StringBuilder\nStream Approach\r\nLine by Line Reading\rAnother line"
+        );
+
+        sb.toString()
+          .lines()
+          .forEach(System.out::println);
+
+    }
+}

core-java-modules/core-java-8-datetime-4/src/main/java/com/baeldung/instantandlong/InstantAndLong.java

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+package com.baeldung.instantandlong;
+
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
+
+public class InstantAndLong {
+
+    public static void main(String[] args) {
+        long nowLong = Instant.now().toEpochMilli();
+
+        long someDayLong = 1_753_610_399_076L;
+        Instant someDay = Instant.ofEpochMilli(someDayLong);
+
+        long expirationPeriod = 2_592_000_000L; // 30 days in milliseconds
+        Instant now = Instant.now();
+        Instant expirationTime = now.plus(expirationPeriod, ChronoUnit.MILLIS);
+
+        expirationTime = Instant.now().plusMillis(2_592_000_000L);
+
+        Instant aDayAgo = now.minus(86_400_000L, ChronoUnit.MILLIS);
+
+        aDayAgo = now.plus(-86_400_000L, ChronoUnit.MILLIS);
+        
+        expirationPeriod = 30    // number of days
+                         * 24    // hours in one day
+                         * 3600  // seconds in one hour
+                         * 1000L;// from seconds to milliseconds
+
+        nowLong = Instant.now().toEpochMilli();
+
+        long expirationTimeLong = nowLong + expirationPeriod;
+    }
+
+}

core-java-modules/core-java-8-datetime-4/src/test/java/com/baeldung/instantandlong/InstantAndLongUnitTest.java

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+package com.baeldung.instantandlong;
+
+
+import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.time.temporal.ChronoUnit;
+import java.util.Locale;
+
+public class InstantAndLongUnitTest {
+
+    private long someDayLong = 1_753_610_399_076L;
+    private long oneDayLong = 86_400_000L;
+    private String stringDate = "2025-01-30T17:33:21";
+    //2025.01.30 17:33:21 in milliseconds, Java epoch
+    private long dayInMillis = ((((2025 - 1970) * 365 + 29 + 14) * 24 // days, including an additional day for each of the 14 leap years
+                                + 17) * 3600  //to seconds
+                                + 33*60 + 21) //add minutes and seconds
+                                * 1000L;      //to milliseconds
+
+    @Test
+    public void whenPlusMillis_thenNextDay() {
+        Instant someDay = Instant.ofEpochMilli(someDayLong);
+        Instant nextDay = someDay.plusMillis(oneDayLong);
+
+        assertEquals(nextDay.toEpochMilli(), someDayLong + oneDayLong);
+    }
+
+    @Test
+    public void whenPlus_thenNextDay() {
+        Instant someDay = Instant.ofEpochMilli(someDayLong);
+        Instant nextDay = someDay.plus(oneDayLong, ChronoUnit.MILLIS);
+
+        assertEquals(nextDay.toEpochMilli(), someDayLong + oneDayLong);
+    }
+
+    @Test
+    public void whenMinusMillis_thenPreviousDay() {
+        Instant someDay = Instant.ofEpochMilli(someDayLong);
+        Instant previousDay = someDay.minusMillis(oneDayLong);
+
+        assertEquals(previousDay.toEpochMilli(), someDayLong - oneDayLong);
+    }
+
+    @Test
+    public void whenMinus_thenPreviousDay() {
+        Instant someDay = Instant.ofEpochMilli(someDayLong);
+        Instant previousDay = someDay.minus(oneDayLong, ChronoUnit.MILLIS);
+
+        assertEquals(previousDay.toEpochMilli(), someDayLong - oneDayLong);
+    }
+
+    @Test
+    public void whenToEpochMilli_thenDaysInMillis() {
+        LocalDateTime dateTime = LocalDateTime.parse(stringDate, DateTimeFormatter.ISO_LOCAL_DATE_TIME);
+        ZonedDateTime zonedDateTime = dateTime.atZone(ZoneId.of("UTC"));
+        Instant instant = zonedDateTime.toInstant();
+
+        assertEquals(instant.toEpochMilli(), dayInMillis);
+    }
+
+    @Test
+    public void whenOfEpochMilli_thenDateTimeAsInstant() {
+        LocalDateTime dateTime = LocalDateTime.parse(stringDate, DateTimeFormatter.ISO_LOCAL_DATE_TIME);
+        ZonedDateTime zonedDateTime = dateTime.atZone(ZoneId.of("UTC"));
+        Instant instant = zonedDateTime.toInstant();
+
+        assertEquals(Instant.ofEpochMilli(dayInMillis), instant);
+    }
+
+}
+

core-java-modules/core-java-collections-list-8/src/test/java/com/baeldung/listwithnullorempty/ListNullOrEmptyUnitTest.java

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+package com.baeldung.listwithnullorempty;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ListNullOrEmptyUnitTest {
+
+    List<String> list = Arrays.asList("Madrid", null, "  ", "Havana", "");
+
+    @Test
+    void givenListWithNullOrEmpty_whenCheckForNullOrEmptyUsingForLoop_thenReturnTrue() {
+        boolean hasNullOrEmpty = false;
+        for (String s : list) {
+            if (s == null || s.isEmpty()) {
+                hasNullOrEmpty = true;
+                break;
+            }
+        }
+
+        assertTrue(hasNullOrEmpty, "List should contain null or empty elements");
+    }
+
+    @Test
+    void givenListWithNullOrEmpty_whenCheckForNullOrEmptyUsingStreams_thenReturnTrue() {
+        boolean hasNullOrEmpty = list.stream()
+          .anyMatch(s -> s == null || s.isEmpty());
+
+        assertTrue(hasNullOrEmpty, "List should contain null or blank elements");
+    }
+
+    @Test
+    void givenListWithNullOrEmpty_whenCheckUsingParallelStream_thenReturnTrue() {
+        boolean hasNullOrEmpty = list.parallelStream()
+                .anyMatch(s -> s == null || s.isEmpty());
+
+        assertTrue(hasNullOrEmpty, "List should contain null or empty elements");
+    }
+
+}