Code commit for "Converting String to BigDecimal in Java" - Article (#10775)

core-java-modules/core-java-string-conversions-2/src/test/java/com/baeldung/stringtobigdecimal/StringToBigDecimalConversionUnitTest.java

@@ -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(bigDecimal, new BigDecimal("123"));
+	}
+
+	@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 = new BigDecimal(123.42).setScale(2, BigDecimal.ROUND_HALF_UP);
+		assertEquals(bigDecimal, BigDecimal.valueOf(Double.valueOf("123.42")));
+	}
+
+	@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("&");
+	}
+
+}