Thread: Reverse every pair of words in a string

Hi, i am trying to create a method that will accept a string, it will then return a string with every pair of words in the first string reversed.

For example, input string: " Hello this is a test string to reverse every pair of words "
output string: " this Hello a is string test reverse to pair every words of"

so far i have below but i am stuck and really need help. I really appreciate it. Thanks

//
public static String wordPairReverse(String source){
 
		StringTokenizer st = new StringTokenizer(source, " ");
		String strReversedLine = "";
		char j=0;
 
		while(st.hasMoreTokens()){
 
			while(j<2){
 
			strReversedLine=st.nextToken()+" "+strReversedLine;
			j++;
 
 
 
		...
 
	}
//

I tried this, but i am getting all sorts of errors. Could someone please suggest a better way if possible. Thanks.

//

public static String wordPairReverse(String source){

StringTokenizer st = new StringTokenizer(source, " ");
String strReversedLine = "";
String tempString = "";
String pairs[]= new String[20];
char j=0;
char i=0;

while(st.hasMoreTokens()){

while(j<2){

tempString=st.nextToken()+" "+tempString;
j++;
}
j=0;
pairs[i]=tempString;
i++;
}

while(i>0){
strReversedLine = pairs[i] + " " + strReversedLine;
i--;
}

return strReversedLine;

}
//

Its telling me out of bounds exception. I have been trying hours now to get this code working but no success. Can someone please suggest the way i should do it please.