Java 10 NumberFormat无法以指数格式解析double

Question

I have recently upgraded from Java 8 to Java 10. I have come across a failing test using Java 10 which I am not sure how to handle. We have some code that is parses String representation of double values into double values using java.text.NumberFormat.getInstance() . In the cases where the value is written in exponential form, the parsed value is incorrect when using Java 10.

Here's my JUnit test:

@Test
public void testMe() throws ParseException {
    String input = "2.0E-4";
    double output = NumberFormat.getInstance().parse(input).doubleValue();
    System.out.println(output);
}

When using Java 8, the double variable is correctly set to 0.0002:

When using Java 10, the double value is incorrectly set to 2.0:

Does anyone know if this is an intentional change on Java's part?

---

It seems like Double.valueOf() parses it correctly, though.

Answer 1

From JDK 9 onwards, the default locale data uses data derived from the Unicode Consortium's Common Locale Data Repository (CLDR). So there are changes with respect to some locales in Java 9 and later. Refer the release notes of Java 9 and the corresponding JEP 252 .

Refer the exponential symbol at the CLDR number symbols chart, for en_AU the exponential symbol is e (lower case) rather than E (upper case). Hence, the difference in output.

String input = "2.0e-4";
double output = NumberFormat.getInstance().parse(input).doubleValue();
System.out.println(output);

will give the expected output :

java version "10.0.1" 2018-04-17
Java(TM) SE Runtime Environment 18.3 (build 10.0.1+10)
Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10.0.1+10, mixed mode)
2.0E-4