Extracting a substring from a given string pattern-CodePudding

Here are the Strings:

Example 1 - Movie=HULK/Incredible HULK;old_actor=Edward Norton;new_actor=Mark Ruffalo

Example 2 - Movie=HULK/Incredible HULK;old_movie_release_date=12 December 2008;new_movie_release_date=20 June 2012

How can I extract values like old_actor, new actor from example 1 and new_movie_release_date and old_movie_release_date from example 2.

I'm new to regex trying to see how can this be done. Thanks in advance.

CodePudding user response：

You can do using java regex as follows

String str1 = "Movie=HULK/Incredible HULK;old_actor=Edward Norton;new_actor=Mark Ruffalo";
String str2 = "Movie=HULK/Incredible HULK;old_movie_release_date=12 December 2008;new_movie_release_date=20 June 2012";

String pattern1="Movie=(.*?);old_actor=(.*?);new_actor=(.*?)$";
String pattern2="Movie=(.*?);old_movie_release_date=(.*?);new_movie_release_date=(.*?)$";

Matcher m1 =  Pattern.compile(pattern1).matcher(str1);
if (m1.find()) {    
    System.out.println("old_actor: "   m1.group(2));
    System.out.println("new_actor: "   m1.group(3));
}  

Matcher m2 = Pattern.compile(pattern2).matcher(str2);
if (m2.find()) {    
    System.out.println("old_movie_release_date: "   m2.group(2));
    System.out.println("new_movie_release_date: "   m2.group(3));
}

CodePudding user response：

You could use String.split(String regex). First, you use String.split(";"), which will give you an array String[] values with contents looking like Movie=moviename, then you use String.split("=") on each string in the first array

for(String str : values) {
String[] keyValue = str.split("=");
}

to create subarrays of length 2 with key at position 0 and value at position 1.

CodePudding user response：

Just an enhancement to @DerLebkuchenmann's solution

  public static void main(String[] args) {
    String str1 = "Movie=HULK/Incredible HULK;old_actor=Edward Norton;new_actor=Mark Ruffalo";
    String str2 = "Movie=HULK/Incredible HULK;old_movie_release_date=12 December 2008;new_movie_release_date=20 June 2012";

    Map<String, String> props1 = getProps(str1);
    Map<String, String> props2 = getProps(str2);

    System.out.println(String.format("Old Actor: %s", props1.get("old_actor")));
    System.out.println(String.format("Old Movie Release Date: %s", props2.get("old_movie_release_date")));
    System.out.println(String.format("New Movie Release Date: %s", props2.get("new_movie_release_date")));
  }

  private static Map<String, String> getProps(String str1) {
    return Arrays.stream(str1.split(";"))
        .map(pair -> pair.split("="))
        .collect(Collectors.toMap(crumbs -> crumbs[0], crumbs -> crumbs[1]));
  }

CodePudding user response：

Another approach using StringTokenizer and assembling a HashMap for result:

public class Main
{
    public static void main(String[] args) {
        HashMap<String,String> m = new HashMap<String,String>();
        StringTokenizer st = new StringTokenizer("Movie=HULK/Incredible HULK;old_actor=Edward Norton;new_actor=Mark Ruffalo",";=");
        while(st.hasMoreTokens()) {
            String s = st.nextToken();
            if (st.hasMoreTokens()) { // ensure well-formed
                m.put(s,st.nextToken());
            }
        }
        System.out.println(m);
    }
}

Prints:

{Movie=HULK/Incredible HULK, old_actor=Edward Norton, new_actor=Mark Ruffalo}