一些小转换

/**
 * 四舍五入
 */		
  DecimalFormat   df=new   DecimalFormat("#");   //不保留小数点
		  double   d=0;   
		double  PriceInRate = 0;
		DecimalFormat df4  = new DecimalFormat("###.0000");
		if(PriceInRate > 0){
			PriceInRate = Double.parseDouble(df4.format(PriceInRate));//保留四位小数
		}

 

/**
 * 得到系统前5天时间
 * <p>Author: sisi
 * <p>Create Time: 2010-8-26
 */
		Calendar calendar = Calendar.getInstance();//系统当前时间
        calendar.add(Calendar.DATE, -5);    //得到前5天
        String  yesterDayDate  = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(calendar.getTime());
        System.out.println(yesterDayDate);

 

/**
 * 路径的替换
 * <p>Author: sisi
 * <p>Create Time: 2010-8-26
 */
  String filePath = "aa \\bb\\\\cc\\\\\\\\dd";
  System.out.println("filePath =" + filePath);
  filePath = filePath.replaceAll("\\\\", "\\\\\\\\");
  System.out.println("filePath2 =" + filePath);

/**
	 * Substring
	 */

		String a = "123456789";
		System.out.println("substring:"+a.substring(1, a.length()));
		System.out.println("a.length():"+a.length());
		
//		substring:23456789
//		a.length():9