Java ArrayList split each object

Question

I'm trying to split each object in the ArrayList because a lot of lines contains comma(","). Each object contains a item and value(but not all objects contains value):

   Access control enable                             ,disabled
   Access policy prototyping                         ,enabled
   Access user group                                 
   Implicit roles access policy                      
   World access policy                               ,disabled

This is my piece of code:

            List<String> CEP = new ArrayList<String>();
            List<String> CEV = new ArrayList<String>();
            for (String str : CE) {
                for (String s : str.split(",")) {
                    CEP.add(s.trim());
                }
            }

"CE" is the main ArrayList.
"CEP" is the ArrayList that should contain only the "items"(what before comma).
"CEV" is the ArrayList that should contain all "values"

My piece of code only split it by comma to the same ArrayList and another problem is how to see an object doesn't have "value" and add blank to the values ArrayList.

Thanks guys.

jschnasse · Accepted Answer · 2018-08-29 07:52:57Z

2

Maybe using a CSV parser like super-csv is a good option. It will really pay off when your comma separated list starts to become more diverse.

Univocity provides a benchmark of CSV parsers. It says that univocity-parsers is fast, which is no surprise. You could give it a try.

answered Aug 29, 2018 at 7:52

jschnasse

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Comments

ernest_k · Accepted Answer · 2018-08-29 07:54:39Z

1

Using an array and checking its length allows you to handle the missing values:

for (String str : CE) {
    String[] a = str.split(",");
    CEP.add(a[0].trim());
    if(a.length > 1) {
        CEV.add(a[1].trim());
    } else {
        CEV.add(null); //just check that this is OK
    }
}

Just make sure that the value being added to CEV for missing values (null in the above code) is as required.

answered Aug 29, 2018 at 7:54

ernest_k

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Comments

deHaar · Accepted Answer · 2018-08-29 07:59:20Z

You could split and check the length of the array afterwards:

public static void main(String[] args) {
    List<String> ce = new ArrayList<String>();

    ce.add("Access control enable                             ,disabled");
    ce.add("Access policy prototyping                         ,enabled");
    ce.add("Access user group                                 ");
    ce.add("Implicit roles access policy                      ");
    ce.add("World access policy                               ,disabled");

    Map<String, String> cepCev = new HashMap<String, String>();

    ce.forEach((String line) -> {
        String[] splitLine = line.split(",");
        if (splitLine.length > 1) {
            cepCev.put(splitLine[0].trim(), splitLine[1].trim());
        } else {
            cepCev.put(splitLine[0].trim(), "not set");
        }
    });

    cepCev.forEach((String key, String value) -> {
        System.out.println(key + ": " + value);
    });
}

Rupesh Agrawal · Accepted Answer · 2018-08-29 08:10:22Z

0

You can do it using java 8 and steam in simple way,

    List<String> CEP = new ArrayList<String>();
    CE.stream().forEach(ce->CEP.addAll(Arrays.asList(ce.split(","))));
    List<String>  CEV= CEP.stream().map(String::trim).filter(s -> s.length()>0).collect(Collectors.toList());

    System.out.println(CEP);
    System.out.println(CEV);

answered Aug 29, 2018 at 8:10

Rupesh Agrawal

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