CCI 1.4 将字符串空格替换成“%20”

编写一个方法，将字符串中的空格全部替换为“%20”。

package test;public class ReplaceSpace {public static char[] replace(char[] str){if(str==null || str.length==0)return str;int count = 0;for(char item : str)if(item==' ')count++;int newLength = str.length + 2*count;char[] newStr = new char[newLength];for(int i=str.length-1; i>=0; i--){if(str[i] == ' '){newStr[newLength-1] = '0';newStr[newLength-2] = '2';newStr[newLength-3] = '%';newLength -= 3;}else{newStr[newLength-1] = str[i];newLength -= 1;}}str = newStr;return str;}public static void main(String[] args) {// TODO Auto-generated method stubchar[] case1 = null;char[] case2 = new char[0];char[] case3 = {'a', ' ', 'b'};char[] case4 = {' ', ' ', ' '};char[] result = replace(case3);System.out.println(result);}}