M/KB/byte之间的转换

public class FormatUtil {
	public static double pers = 1048576; //1024*1024
	
	//long==> 616.19KB,3.73M 
	public static String sizeFormatNum2String(long size) {
    	String s = "";
    	if(size>1024*1024)
    		s=String.format("%.2f", (double)size/pers)+"M";
    	else 
    		s=String.format("%.2f", (double)size/(1024))+"KB";
		return s;
	}
	
	//616.19KB,3.73M ==> long
	public static long sizeFormatString2Num(String str){
		long size = 0;
		if(str!=null){
			if(str.endsWith("KB"))
				size = (long)(Double.parseDouble(str.substring(0,str.length()-2))*1024);
			else if(str.endsWith("M"))
				size = (long)(Double.parseDouble(str.substring(0,str.length()-1))*pers);
		}
		return size;
		
	}
}