Reverse string with word in Java

I have the following code to reverse the string word by word, but I have a question. First, can someone point out how to make it better? Second, how to delete the space I finally get at the beginning of the new string

String str = "hello brave new world";
tStr.reverseWordByWord(str)

public String reverseWordByWord(String str){
        int strLeng = str.length()-1;
        String reverse = "",temp = "";

        for(int i = 0; i <= strLeng; i++){
            temp += str.charAt(i);
            if((str.charAt(i) == ' ') || (i == strLeng)){
                for(int j = temp.length()-1; j >= 0; j--){
                    reverse += temp.charAt(j);
                    if((j == 0) && (i != strLeng))
                        reverse += " ";
                }
                temp = "";
            }
        }

        return reverse;
    }

Now the phrase becomes:

Notice the space at the beginning of the new string

Solution

Without using the split function, the code looks like:

public static void reverseSentance(String str) {
    StringBuilder revStr = new StringBuilder("");
    int end = str.length(); // substring takes the end index -1
    int counter = str.length()-1;
    for (int i = str.length()-1; i >= 0; i--) {     
        if (str.charAt(i) == ' ' || i == 0) {
            if (i != 0) {
                revStr.append(str.substring(i+1,end));
                revStr.append(" ");
            }
            else {
                revStr.append(str.substring(i,end));
            }
            end = counter;
        }
        counter--;
    }
    System.out.println(revStr);
}