Java中的 NumberFormat setRoundingMode() 方法及示例
setRoundingMode()方法是Java.text.NumberFormat 的内置方法,用于设置此 NumberFormat 中使用的 RoundingMode。处理不同舍入模式的子类应覆盖此方法。
句法:
public void setRoundingMode(RoundingMode mode)
参数:该函数接受一个强制参数模式,该参数指定要设置的模式。
返回值:该函数不返回任何内容,因此返回类型为 void。
异常:该函数抛出两个异常,如下所述:
- UnsupportedOperationException :如果默认实现总是抛出这个异常
- NullPointerException : 如果 roundingMode 为空
下面是上述函数的实现:
程序 1 :
Java
// Java program to implement
// the above function
import java.text.NumberFormat;
import java.util.Locale;
import java.util.Currency;
import java.math.RoundingMode;
public class Main {
public static void main(String[] args)
throws Exception
{
NumberFormat nF
= NumberFormat.getNumberInstance();
System.out.println("set initially as: "
+ nF.getRoundingMode());
// Set grouping
nF.setRoundingMode(RoundingMode.FLOOR);
// Print the final
System.out.println("set finally as: "
+ nF.getRoundingMode());
}
}
Java
// Java program to implement
// the above function
import java.text.NumberFormat;
import java.util.Locale;
import java.util.Currency;
import java.math.RoundingMode;
public class Main {
public static void main(String[] args)
throws Exception
{
NumberFormat nF
= NumberFormat.getNumberInstance();
System.out.println("set initially as: "
+ nF.getRoundingMode());
// Set grouping
nF.setRoundingMode(RoundingMode.DOWN);
// Print the final
System.out.println("set finally as: "
+ nF.getRoundingMode());
}
}
Java
// Java program to implement
// the above function
import java.text.NumberFormat;
import java.util.Locale;
import java.util.Currency;
import java.math.RoundingMode;
public class Main {
public static void main(String[] args)
throws Exception
{
try {
NumberFormat nF
= NumberFormat.getNumberInstance();
System.out.println("set initially as: "
+ nF.getRoundingMode());
// Set grouping
nF.setRoundingMode(null);
// Print the final
System.out.println("set finally as: "
+ nF.getRoundingMode());
}
catch (Exception e) {
System.out.println("Exception is: "
+ e);
}
}
}
输出:
set initially as: HALF_EVEN
set finally as: FLOOR
方案二:
Java
// Java program to implement
// the above function
import java.text.NumberFormat;
import java.util.Locale;
import java.util.Currency;
import java.math.RoundingMode;
public class Main {
public static void main(String[] args)
throws Exception
{
NumberFormat nF
= NumberFormat.getNumberInstance();
System.out.println("set initially as: "
+ nF.getRoundingMode());
// Set grouping
nF.setRoundingMode(RoundingMode.DOWN);
// Print the final
System.out.println("set finally as: "
+ nF.getRoundingMode());
}
}
输出:
set initially as: HALF_EVEN
set finally as: DOWN
方案 3:
Java
// Java program to implement
// the above function
import java.text.NumberFormat;
import java.util.Locale;
import java.util.Currency;
import java.math.RoundingMode;
public class Main {
public static void main(String[] args)
throws Exception
{
try {
NumberFormat nF
= NumberFormat.getNumberInstance();
System.out.println("set initially as: "
+ nF.getRoundingMode());
// Set grouping
nF.setRoundingMode(null);
// Print the final
System.out.println("set finally as: "
+ nF.getRoundingMode());
}
catch (Exception e) {
System.out.println("Exception is: "
+ e);
}
}
}
输出:
set initially as: HALF_EVEN
Exception is: java.lang.NullPointerException
参考:https: Java