剑指Offer 2.替换空格

public class Solution {
public String replaceSpace(StringBuffer str) {
return str.toString().replaceAll("\\s", "%20");
}
}

public class Solution {
public String replaceSpace(StringBuffer str) {
StringBuffer out=new StringBuffer();
for (int i = 0; i < str.toString().length(); i++) {
char b=str.charAt(i);
if(String.valueOf(b).equals(" ")){
out.append("%20");
}else{
out.append(b);
}
}
return out.toString();
}
}