7-替换空格

 1 public class Demo6 {
 2 
 3     public static void main(String[] args) {
 4         String str = "We Are Happy";
 5         String replaceSpace = replaceSpace(new StringBuffer(str));
 6         System.out.println(replaceSpace);
 7     }
 8 
 9     public static String replaceSpace(StringBuffer str) {
10         if(str == null){
11             return null;
12         }
13         //把str转成String类型
14         String string = str.toString();
15         String replaceStr = string.replace(" ", "%20");
16         return replaceStr;
17     }
18 }