将多个if语句添加到arrayList java

Question

I am reading in a textfile into my class. I would like to add to a specific arrayList when the if condition is met. At the moment the arrayList keeps on being written over and I don't know why. Here is the code:

The calling class:

public String PatternPDF (String s) throws IOException, ClassNotFoundException {
        ArrayList<String>arr=new ArrayList<String>();
        for (String line : Files.readAllLines(Paths.get("Fields2Extract.txt"))){
            //System.out.println(line);
            arr.add(line);
        }
        for (String pattern:arr){
            OrganisePDF(pattern,s);
        }
        return pattern;
    }

The arrayList class

public void  OrganisePDF (String pattern,String s) {
    ArrayList<String> Chicago =new ArrayList<String>();
    Pattern patternorganise = Pattern.compile(pattern);
    Matcher matcherpatternorganise_pattern = patternorganise.matcher(s);
    String h="";
            while (matcherpatternorganise_pattern.find()){
                 h=matcherpatternorganise_pattern.group(0);
                 all.add(h);
            }


            for (String n:all){
                if(n.contains("something good")||n.contains("a load of buses")){
                    n=n.replaceAll("\\n", "").trim();
                    Chicago.add(n);
                       }
            }

    System.out.prinln("Chicago"+Chicago);
}

This gives me

Chicago[something good]
Chicago[a load of buses]

Whereas I'm hoping for

Chicago[something good,a load of buses]

Answer 1

You are getting this because you are not concatenating the results in the match of the regex.

try something like appending the match in a stringbuilder and after the for loop add it to chicago list:

StringBuilder sb = new StringBuilder();
for (String n:all){
    if(n.contains("something good")||n.contains("a load of buses")){
        n=n.replaceAll("\\n", "").trim();
        sb.append(n);
    }

}
Chicago.add(sb.toString());

Answer 2

list.add(1, object1)
StringBuilder builder = new StringBuilder();
for (String n:all){
    if(n.contains("something good")||n.contains("a load of buses")){
        n=n.replaceAll("\\n", "").trim();
        builder.append(n);
        Chicago.add(0,builder.toString()); //this will add the data to a specific position
    }
}

i dont know why you want to do this weird thing , but you can try it this way chicago.add(0,ojec); this will add data to given position each time its called.