BigDecimalTest.java

package com.example;

import java.math.BigDecimal;
import java.math.MathContext;
import java.math.RoundingMode;

public class BigDecimalTest {
	public static void main(String... args) {
		print(new BigDecimal(1));
		print(new BigDecimal(1.12));
		print(new BigDecimal("1.12"));
		print(new BigDecimal(1.12, new MathContext(1, RoundingMode.FLOOR)));
		print(new BigDecimal(0.12, new MathContext(1, RoundingMode.FLOOR)));

		BigDecimal bd1 = new BigDecimal(1);
		BigDecimal bd3 = new BigDecimal(3);
		print(bd1.divide(bd3, new MathContext(3, RoundingMode.FLOOR)));
	}

	public static void print(BigDecimal bd) {
		System.out.println(bd.toPlainString() + " precision=" + bd.precision()
				+ " scale=" + bd.scale());
	}
}

/* result
1 precision=1 scale=0
1.12000000000000010658141036401502788066864013671875 precision=51 scale=50
1.12 precision=3 scale=2
1 precision=1 scale=0
0.1 precision=1 scale=1
0.333 precision=3 scale=3
*/