BigDecimal divide question

[Tariq Ahsan]

Hello All,

Was getting the error - "java.lang.ArithmeticException: Non-terminating decimal expansion; no exact representable decimal result" while trying to do a divide of a BigDecimal by a BigDecimal. Found some code that I used to solve this problem above. The code I have does not look pretty. Wondering if there is a easier way to do the same.
Here's the code I have -

import java.math.*;

public class BDDivide {

	public static void main(String[] args) {

		BigDecimal bd = new BigDecimal(0.4);
		MathContext mc1 = new MathContext(2, RoundingMode.HALF_EVEN);

		// Divide by 3
		MathContext mc = new MathContext((int) Math.min(bd.precision()
				+ (long) Math.ceil(10.0 * BigDecimal.valueOf(3).precision() / 3.0),
				Integer.MAX_VALUE), RoundingMode.HALF_EVEN);

		BigDecimal quotient = bd.divide(BigDecimal.valueOf(3), mc).round(mc1);

		System.out.println("The value of quotient : " + quotient);

	}

}

Here's the output -

The value of quotient : 0.13

[Garrett Rowe]

How many decimal places do you want to represent?

import java.math.*;

public class BDTest {

   public static void main(String[] args) {
      BigDecimal num = new BigDecimal("0.4");
      BigDecimal den = new BigDecimal("3.0");
      BigDecimal res = num.divide(den, MathContext.DECIMAL32);
      System.out.println(res);
   }
}

[Tariq Ahsan]

Thanks Garrett for your response. I would like to have 2 decimal places.

[Tariq Ahsan]

Garrett,

Just tried the changes below with your code to get 2 decimal position output. Is there any other simpler way?

import java.math.*; 

public class BDTest {   
  
   public static void main(String[] args) {   
      BigDecimal num = new BigDecimal(0.512);   
      BigDecimal den = new BigDecimal(3);
      MathContext mc = new MathContext(2, RoundingMode.HALF_EVEN);
      BigDecimal res = num.divide(den, MathContext.DECIMAL32).round(mc);   
      System.out.println(res);   
   }   
}

The output :

0.17

[Garrett Rowe]

This is a little simpler:

import java.math.*; 

public class BDTest {   
  
   public static void main(String[] args) {   
      BigDecimal num = new BigDecimal(0.512);   
      BigDecimal den = new BigDecimal(3);
      MathContext mc = new MathContext(2, RoundingMode.HALF_EVEN);
      BigDecimal res = num.divide(den, mc);   
      System.out.println(res);   
   }   
}

[Tariq Ahsan]

Garrett,

Worked perfectly!

Thanks a lot!

Tariq

[Tariq Ahsan]

Ugh...

The code did'nt quite work for me for the inputs as shown below -

import java.math.*;    
  
public class BDTest {      
     
   public static void main(String[] args) {      
      BigDecimal num = new BigDecimal(1.16);      
      BigDecimal den = new BigDecimal(0.014808);   
      MathContext mc = new MathContext(2, RoundingMode.HALF_EVEN);   
      BigDecimal res = num.divide(den, mc);      
      System.out.println(res);      
   }      
} 

Getting the output as - 78. But expect - 78.34

Any suggestions?

Thanks

[Campbell Ritchie]

Read the MathContext specification. The 2 appears to refer to significant figures, not places after the decimal point.

[Tariq Ahsan]

Any idea if I want to have result to be with 2 decimal points? Eventually I have to store the output value in NUMBER(9,2) datatype column in a database table.

Thanks

[Campbell Ritchie]

There are several overloaded divide methods. Have you been through them? Are they of any use? Note what "scale" means.

[Tariq Ahsan]

So far, the code below is working for me. But again need to try out exhaustively with all kinds of decimal value combinations.

import java.math.*;       
     
public class BDTest {         
        
   public static void main(String[] args) {  

      BigDecimal num = new BigDecimal(1.16);      
      BigDecimal den = new BigDecimal(.014808);   
      MathContext mc = new MathContext(9, RoundingMode.CEILING);   
      BigDecimal res = num.divide(den, mc).setScale(2, RoundingMode.CEILING);      
      System.out.println(res);
  }
}

Getting 78.34 as expected

[Tariq Ahsan]

Or better use -

import java.math.*;          
        
public class BDTest {            
           
   public static void main(String[] args) {     
  
      BigDecimal num = new BigDecimal(1.17);         
      BigDecimal den = new BigDecimal(.014808);      
      MathContext mc = new MathContext(9, RoundingMode.HALF_EVEN);      
      BigDecimal res = num.divide(den, mc).setScale(2, RoundingMode.HALF_EVEN);         
      System.out.println(res);   
  }
  
} 

Was getting 79.02 with CEILING. With HALF_EVEN getting the correct result - 79.01. For the num with 1.16 getting the expected 78.34.