Java 格式化和解析数字

​

import java.text.DecimalFormat;

​

import java.text.ParsePosition;

​

/** 

 来自 时代Java公众号**/

​

public class Main {

​

  private static DecimalFormat formatter = new DecimalFormat();

​

  public static void main (String[] args){

​

    formatNumber("##.##", 12.456);

​

    formatNumber("##.##", 12.456);

​

    formatNumber("0000.0000", 123.456);

​

    formatNumber("#.##", -123.456);

​

​

    // Positive and negative number format

​

    formatNumber("#.##;(#.##)", -123.345); 

​

​

    // Parse a string to decimal number

​

    String str = "XY4,123.123";

​

    String pattern = "#,###.###";

​

    formatter.applyPattern(pattern);

​

​

    // Create a ParsePosition object to specify the first digit of 

​

    // number in string. It is 4 in "XY4,123.983" and its index is 2./*NowJava.com - 时  代  Java 提 供*/

​

    ParsePosition pp = new ParsePosition(2);

​

​

    Number numberObject = formatter.parse(str, pp);

​

​

    double value = numberObject.doubleValue();

​

    System.out.println("Parsed Value is " + value);

​

  }

​

​

  public static void formatNumber(String pattern, double value) {

​

      // Apply the pattern

​

      formatter.applyPattern ( pattern );

​

​

      // Format the number

/**代码未完, 请加载全部代码(NowJava.com).**/