aaaaaaaaa

public static void test(){
try {
String str="";
String aa="";

File f=new File("C:/a.txt");
BufferedReader br = new BufferedReader(new FileReader(f));
while((aa=br.readLine())!=null){
str+=aa;
}
System.out.println(str);
String bb="";
char[] strs=str.toCharArray();

for(int i=0;i<3;i++){
for(int j=i;j<str.length();j+=3){
bb+=String.valueOf(strs[j]);
}
}

f=new File("C:/b.txt");
BufferedWriter bw=new BufferedWriter(new FileWriter(f));
for(int i=0;i<bb.length();i+=3){
bw.write(bb.substring(i, i+3)+"\r\n");
}
bw.close();
System.out.println(bb.toString());

} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}