1 ////替换空格
 2     private static char[] replaceTrim(char[] str1,char[] tidai) {
 3         // TODO 自动生成的方法存根
 4         int count=0;
 5         for (int i = 0; i < str1.length; i++) {
 6              if (str1[i]==‘ ‘) {
 7                 count++;
 8             }
 9         }
10         ///传入替代的符号的长度-空格的长度就是新的到的长度
11         int size=str1.length+count*(tidai.length-1); 
12         char[] newstring=new char[size];
13         size--;
14         for (int i = str1.length-1; i >=0; i--) {
15              if (str1[i]==‘ ‘) {
16                  for (int j = 0; j < tidai.length; j++) {
17                      newstring[size-j]=tidai[tidai.length-j-1];
18                 }
19                  size-=tidai.length;
20             } else {
21                 newstring[size]=str1[i];
22                 size--;
23             }
24         }
25         return newstring;
26     }

  public static void main(String[] args) {
		String str1="ac  b cb ";
		String str2="a b"; 
		System.out.println(replaceTrim(str1.toCharArray(),"%".toCharArray()));
		System.out.println(replaceTrim(str2.toCharArray(),"%5".toCharArray()));
	}