在Java中使用indexOf拆分字符串时出现问题

Question

I'm doing a Java IRC API project using pircbot that requires me to implement a weather API. However, something that's getting in the way of testing it is handling the message String. I'm trying to do it like so- the user enters:

(City) weather (component)

ex: Austin weather gust

and this indicates the user wants to use the weather API to get the gust information in Austin . To do so, I want to "split up" the string and put the (City) and (component) substrings in their own strings. I tried to do it like so:

else if (message.contains("weather")) {
        String component;
        String city;
        int indexA = 0;
        int indexB = message.indexOf(" weather");

        int indexC = (message.indexOf("weather") + 6);
        int indexD = message.length() + 1;

        city = message.substring(indexA, indexB);
        component = message.substring(indexC, indexD);

        startWebRequestName(city, component, sender, channel);
    }

and that didn't seem to work so I started to experiment in a test class:

public static void main (String args[]) {
        String message = "Austin weather gust";

        int firstIndex = message.indexOf("weather");
        System.out.println(firstIndex);
    }

And after messing around, indexOf seems to work for every char and substring contained in "Austin" but not anything after that. For anything after "Austin", like "weather", "w", or "gust", indexOf returns -1, which is odd because I am positive those things are in there haha. Any ideas?

Also, please let me know if I need to elaborate on anything. I have a feeling this was explained kind of poorly.

Answer 1

If you can make sure the input string is always in the format you gave above and with no exceptions , you can simply use the following method to get the city & component values quickly.

    String inputString = "Austin weather gust";
    String[] separatedArray = inputString.split(" ");
    String city = separatedArray[0];
    String component = separatedArray[2];

Answer 2

Please find the below comments.

private static void cityFetcher(String message) {
    if (message.contains("weather")) {
        String component;
        String city;
        int indexA = 0;
        int indexB = message.indexOf(" weather");

        int indexC = (message.indexOf("weather") + 6);
        System.out.println(indexC); //13
        int indexD = message.length() + 1;
        System.out.println(indexD);//20
        city = message.substring(indexA, indexB);
        System.out.println(city);//Austin
        component = message.substring(indexC, indexD);//if no -1 then ooi bound exception as your trying to access until 20th element. When your input size is only 19.
        System.out.println(component);// r gust

}

Solution. You may use either of the 2 if your input formats are what you claim to be the same.

private static void cityFetcher(String input){
    //Solution 1
    String[] params=input.split("\\s");
    for(String s:params){
        System.out.println(s);
    }

    //Solution 2

    String city=input.substring(0,input.indexOf(" "));
    System.out.println(city);
    String component=input.substring(input.lastIndexOf(" ")+1,input.length());
    System.out.println(component);

}