package base.util;

import java.util.Date;
import java.util.Random;

public class StringTransform {
	public static String getInsureString(String str) {
		return str == null ? "" : str;
	}
	//轉(zhuǎn)換編碼
	public static String TransformEncoding(String str) {
		try {
			byte[] bytes = str.getBytes("ISO8859_1");
			return new String(bytes);
		} catch (Exception e) {
			return "";
		} 
	}
	/*獲取格式化后的字符串，如 1:00返回 01:00 , 
	2返回02 ,后一個(gè)參數(shù)是前面要補(bǔ)齊的字符，如0 或 #    */
	public static String format(String bak,int digit,String content){
	        int length=digit-bak.length();
	        StringBuffer buffer=new StringBuffer();
	        for(int index=0;index<length;index++){
	            buffer.append(content);
	        }
	        return buffer.append(bak).toString();
	}
	//字符串按分隔符倒轉(zhuǎn)
    public static String inverse(String result,String split){
	    if(result==null||result.equals(""))return "";
	    String array[]=result.split(split);
	    if(array.length==1)return array[0];
	    StringBuffer buffer=new StringBuffer(array[array.length-1]);
	    for(int i=array.length-2;i>=0;i--){
	        buffer.append(split+array[i]);
	    }
	    return buffer.toString();
	}
    //如果判斷某個(gè)字符串是否全是由數(shù)字組成
	public static boolean isDigit(String str)
	{
		char[] arr=str.toCharArray();
		for(int i=0;i<arr.length;i++)
		{
			if(!Character.isDigit(arr[i]))
			 return false;
		}
		return true;
	}
	//生成一個(gè)唯一字符串，可用來(lái)做主鍵，生成方法:用隨機(jī)數(shù)加當(dāng)前日期
    public static String getKey(){
        String id=String.valueOf(new Random().nextInt(9999));
        int length=4-id.length();
        StringBuffer buffer=new StringBuffer();
        for(int index=0;index<length;index++){
            buffer.append("0");
        }
        buffer.append(new Date().getTime());
        return buffer.append(id).toString();
    }
	public static void main(String[] args) {
		System.out.println(TransformEncoding("大家好!"));
    	System.out.println("北京>>中國(guó)>>地球倒轉(zhuǎn)后是: "+inverse("北京>>中國(guó)>>地球",">>"));
    	System.out.println("22格式化后得到的字符串是:"+format("22", 8,"0"));
    	System.out.println("[2458965a]是不是全部由數(shù)字組成 : "+isDigit("2458965a"));
    	System.out.println("生成到的主鍵id是 : "+getKey());
	}
}