Merge branch 'eugenp:master' into master

2021-05-21 15:11:13 +05:30
parent 3e61f32493 31f40d8623
commit baf1093fb3
190 changed files with 1113 additions and 1258 deletions
@@ -7,3 +7,4 @@ This module contains articles about Java 11 core features
 - [Guide to Java Reflection](http://www.baeldung.com/java-reflection)
 - [Guide to Java 8’s Collectors](https://www.baeldung.com/java-8-collectors)
 - [New Features in Java 11](https://www.baeldung.com/java-11-new-features)
+- [Getting the Java Version at Runtime](https://www.baeldung.com/get-java-version-runtime)
@@ -34,4 +34,4 @@
        <maven.compiler.target>1.9</maven.compiler.target>
    </properties>

-</project>
+</project>
@@ -7,7 +7,7 @@
    <version>0.1.0-SNAPSHOT</version>
    <name>core-java-9-streams</name>
    <packaging>jar</packaging>
-    
+
    <parent>
        <groupId>com.baeldung.core-java-modules</groupId>
        <artifactId>core-java-modules</artifactId>
@@ -25,4 +25,4 @@
        </resources>
    </build>

-</project>
+</project>
@@ -5,3 +5,4 @@ This module contains articles about core features in the Java language
 - [The Java final Keyword – Impact on Performance](https://www.baeldung.com/java-final-performance)
 - [The package-info.java File](https://www.baeldung.com/java-package-info)
 - [What are Compile-time Constants in Java?](https://www.baeldung.com/java-compile-time-constants)
+- [Java Objects.hash() vs Objects.hashCode()](https://www.baeldung.com/java-objects-hash-vs-objects-hashcode)
@@ -7,3 +7,4 @@ This module contains articles about Object-oriented programming (OOP) patterns i
 - [Inheritance and Composition (Is-a vs Has-a relationship) in Java](https://www.baeldung.com/java-inheritance-composition)
 - [Immutable Objects in Java](https://www.baeldung.com/java-immutable-object)
 - [How to Make a Deep Copy of an Object in Java](https://www.baeldung.com/java-deep-copy)
+- [Using an Interface vs. Abstract Class in Java](https://www.baeldung.com/java-interface-vs-abstract-class)
@@ -0,0 +1,54 @@
+package com.baeldung.ignore.pattern.metacharacters;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.junit.Test;
+
+public class IgnoringPatternMetacharactersUnitTest {
+    private static final String dollarAmounts = "$100.25, $100.50, $150.50, $100.50, $100.75";
+    private static final String patternStr = "$100.50";
+
+    @Test
+    public void givenPatternStringHasMetacharacters_whenPatternMatchedWithoutEscapingMetacharacters_thenNoMatchesFound() {
+        Pattern pattern = Pattern.compile(patternStr);
+        Matcher matcher = pattern.matcher(dollarAmounts);
+
+        int matches = 0;
+        while (matcher.find()) {
+            matches++;
+        }
+
+        assertEquals(0, matches);
+    }
+
+    @Test
+    public void givenPatternStringHasMetacharacters_whenPatternCompiledUsingManuallyMetaEscapedPattern_thenMatchingSuccessful() {
+        String metaEscapedPatternStr = "\\Q" + patternStr + "\\E";
+        Pattern pattern = Pattern.compile(metaEscapedPatternStr);
+        Matcher matcher = pattern.matcher(dollarAmounts);
+
+        int matches = 0;
+        while (matcher.find()) {
+            matches++;
+        }
+
+        assertEquals(2, matches);
+    }
+
+    @Test
+    public void givenPatternStringHasMetacharacters_whenPatternCompiledUsingLiteralPatternFromQuote_thenMatchingSuccessful() {
+        String literalPatternStr = Pattern.quote(patternStr);
+        Pattern pattern = Pattern.compile(literalPatternStr);
+        Matcher matcher = pattern.matcher(dollarAmounts);
+
+        int matches = 0;
+        while (matcher.find()) {
+            matches++;
+        }
+
+        assertEquals(2, matches);
+    }
+}
@@ -12,4 +12,5 @@ This module contains articles about the Stream API in Java.
 - [Should We Close a Java Stream?](https://www.baeldung.com/java-stream-close)
 - [Returning Stream vs. Collection](https://www.baeldung.com/java-return-stream-collection)
 - [Convert a Java Enumeration Into a Stream](https://www.baeldung.com/java-enumeration-to-stream)
+- [When to Use a Parallel Stream in Java](https://www.baeldung.com/java-when-to-use-parallel-stream)
 - More articles: [[<-- prev>]](/../core-java-streams-2)
@@ -6,4 +6,5 @@ This module contains articles about string conversions from/to another type.
 - [Java String Conversions](https://www.baeldung.com/java-string-conversions)
 - [Convert String to Byte Array and Reverse in Java](https://www.baeldung.com/java-string-to-byte-array)
 - [Convert Character Array to String in Java](https://www.baeldung.com/java-char-array-to-string)
+- [Converting String to BigDecimal in Java](https://www.baeldung.com/java-string-to-bigdecimal)
 - More articles: [[<-- prev]](/core-java-string-conversions)
@@ -0,0 +1,74 @@
+package com.baeldung.stringtobigdecimal;
+
+import static org.junit.Assert.assertEquals;
+
+import java.math.BigDecimal;
+import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
+import java.text.ParseException;
+
+import org.junit.Test;
+
+public class StringToBigDecimalConversionUnitTest {
+
+	@Test
+	public void givenValidString_WhenBigDecimalObjectWithStringParameter_ThenResultIsDecimalObject() {
+		BigDecimal bigDecimal = new BigDecimal("123");
+		assertEquals(new BigDecimal(123), bigDecimal);
+	}
+
+	@Test(expected = NullPointerException.class)
+	public void givenNullString_WhenBigDecimalObjectWithStringParameter_ThenNullPointerExceptionIsThrown() {
+		String bigDecimal = null;
+		new BigDecimal(bigDecimal);
+	}
+
+	@Test(expected = NumberFormatException.class)
+	public void givenInalidString_WhenBigDecimalObjectWithStringParameter_ThenNumberFormatExceptionIsThrown() {
+		new BigDecimal("&");
+	}
+
+	@Test
+	public void givenValidString_WhenValueOfDoubleFromString_ThenResultIsDecimalObject() {
+		BigDecimal bigDecimal = BigDecimal.valueOf(Double.valueOf("123.42"));
+		assertEquals(new BigDecimal(123.42).setScale(2, BigDecimal.ROUND_HALF_UP), bigDecimal);
+	}
+
+	@Test(expected = NullPointerException.class)
+	public void givenNullString_WhenValueOfDoubleFromString_ThenNullPointerExceptionIsThrown() {
+		BigDecimal.valueOf(Double.valueOf(null));
+	}
+
+	@Test(expected = NumberFormatException.class)
+	public void givenInalidString_WhenValueOfDoubleFromString_ThenNumberFormatExceptionIsThrown() {
+		BigDecimal.valueOf(Double.valueOf("&"));
+	}
+
+	@Test
+	public void givenValidString_WhenDecimalFormatOfString_ThenResultIsDecimalObject() throws ParseException {
+		BigDecimal bigDecimal = new BigDecimal(10692467440017.111).setScale(3, BigDecimal.ROUND_HALF_UP);
+
+		DecimalFormatSymbols symbols = new DecimalFormatSymbols();
+		symbols.setGroupingSeparator(',');
+		symbols.setDecimalSeparator('.');
+		String pattern = "#,##0.0#";
+		DecimalFormat decimalFormat = new DecimalFormat(pattern, symbols);
+		decimalFormat.setParseBigDecimal(true);
+
+		// parse the string value
+		BigDecimal parsedStringValue = (BigDecimal) decimalFormat.parse("10,692,467,440,017.111");
+
+		assertEquals(bigDecimal, parsedStringValue);
+	}
+
+	@Test(expected = NullPointerException.class)
+	public void givenNullString_WhenDecimalFormatOfString_ThenNullPointerExceptionIsThrown() throws ParseException {
+		new DecimalFormat("#").parse(null);
+	}
+
+	@Test(expected = ParseException.class)
+	public void givenInalidString_WhenDecimalFormatOfString_ThenNumberFormatExceptionIsThrown() throws ParseException {
+		new DecimalFormat("#").parse("&");
+	}
+
+}
@@ -3,3 +3,4 @@
 - [Version Comparison in Java](https://www.baeldung.com/java-comparing-versions)
 - [Java (String) or .toString()?](https://www.baeldung.com/java-string-casting-vs-tostring)
 - [Split Java String by Newline](https://www.baeldung.com/java-string-split-by-newline)
+- [Split a String in Java and Keep the Delimiters](https://www.baeldung.com/java-split-string-keep-delimiters)