Guava教程
IntMath提供整型的实用方法。
以下是com.google.common.math.IntMath类的声明:
@GwtCompatible(emulated=true)
public final class IntMath
extends Object
方法
方法继承
这个类从以下类继承的方法: java.lang.Object
选择使用任何编辑器创建以下java程序在 C:/> Guava
GuavaTester.java
import java.math.RoundingMode;
import com.google.common.math.IntMath;
public class GuavaTester {
public static void main(String args[]){
GuavaTester tester = new GuavaTester();
tester.testIntMath();
}
private void testIntMath(){
try{
System.out.println(IntMath.checkedAdd(Integer.MAX_VALUE, Integer.MAX_VALUE));
}catch(ArithmeticException e){
System.out.println("Error: " + e.getMessage());
}
System.out.println(IntMath.divide(100, 5, RoundingMode.UNNECESSARY));
try{
//exception will be thrown as 100 is not completely divisible by 3 thus rounding
// is required, and RoundingMode is set as UNNESSARY
System.out.println(IntMath.divide(100, 3, RoundingMode.UNNECESSARY));
}catch(ArithmeticException e){
System.out.println("Error: " + e.getMessage());
}
System.out.println("Log2(2): "+IntMath.log2(2, RoundingMode.HALF_EVEN));
System.out.println("Log10(10): "+IntMath.log10(10, RoundingMode.HALF_EVEN));
System.out.println("sqrt(100): "+IntMath.sqrt(IntMath.pow(10,2), RoundingMode.HALF_EVEN));
System.out.println("gcd(100,50): "+IntMath.gcd(100,50));
System.out.println("modulus(100,50): "+IntMath.mod(100,50));
System.out.println("factorial(5): "+IntMath.factorial(5));
}
}
验证结果
使用javac编译器编译如下类
C:\Guava>javac GuavaTester.java
现在运行GuavaTester看到的结果
C:\Guava>java GuavaTester
看到结果
Error: overflow
20
Error: mode was UNNECESSARY, but rounding was necessary
Log2(2): 1
Log10(10): 1
sqrt(100): 10
gcd(100,50): 50
modulus(100,50): 0
factorial(5): 120
转载自并发编程网-ifeve.com