Given following Java codes:
String columnValue = "188237574385834583453453635";
columnValue =(Long.parseLong(columnValue)>Long.MAX_VALUE?"0":columnValue);
It throws java.lang.NumberFormatException since the input value is beyond Long's maximum value. However, it there an easy way to detect whether a number in a 'string' type get out of Long's maximum value with out using try catch solution?
A lazy way can be to use BigInteger.
BigInteger a = new BigInteger("188237574385834583453453635");
BigInteger b = BigInteger.valueOf(Long.MAX_VALUE);
System.out.println("a > Long.MAX_VALUE is : " + (a.compareTo(b) > 0 ? "true" : "false"));
If performance is important, you will have to test more solutions.
@SotiriosDelimanolis idea is also a good one :
Extract the source code of parseLong and instead of throwing an exception, return a boolean.
Also there are many throw in the code, some are for the format, other are for the overflow, you will have to choose the right ones.
A really cheesy way:
columnValue.length() > ("" + Long.MAX_VALUE).length()
Of course this does NOT cover values greater than Long.MAX_VALUE but the same number of digits, only values with more digits.
Not really.
The only naive partial solution is to compare the length of the String, but that would not work always.
You can create a utility method that wraps the try/catch and returns a boolean, something like:
import java.util.*;
import java.lang.*;
import java.io.*;
class TestClass
{
public static void main (String[] args) throws java.lang.Exception
{
System.out.println(TestClass.isLongString("188237574385834583453453635"));
}
public static boolean isLongString(final String longNumber)
{
boolean isLong = false;
try
{
Long.parseLong(longNumber);
isLong = true;
}
catch(Exception e)
{
// do nothing - return default false
}
return isLong;
}
}
false result is caused by an overflow or a malformed string.parseLong function did not gives more informations when it throws exceptions (I looked to JDK 8u31 sources). In C# for example you get an OverflowException or a FormatException depending on the cause of the exception.
longvalue can be greater thanLong.MAX_VALUE, by definition.parseLongand instead of throwing an exception, return aboolean. Though, throwing the exception here makes sense, in my opinion.