Splitting string and instantiating the object

Question

I want to split a string based message based on the definition.

    String: AAABBB CCDDD    FFGGGHHHI     KKK
    Definition: 2,6,3,1,6,7,rest
    So,
    2   AA
    6   ABBB C
    3   CDD
    1   D
    6        F
    7   FGGGHHH
    rest    I     KKK

Ideally, if there is an existing mechanism in java or spring which splits the message and instantiates the object that would be ideal.

Possible duplicate of [How to split a string in Java](https://stackoverflow.com/questions/3481828/how-to-split-a-string-in-java) — UmarZaii, Sep 12 '17 at 19:00

holi-java · Answer 1 · 2017-09-12T20:01:43.773

This is exactly what substring does...

static String[] split(String source, int ... sizes){
  int n = source.length(), start = 0;
  String [] partials = new String[sizes.length];

  for(int i = 0; i < sizes.length; i++){
    int end = sizes[i] < 0 ? n : start + sizes[i];
    partials[i] = source.substring(start, start = end);
  }

  return partials;
}

One thing you need to do is translate rest to -1, for example:

static String[] split(String source, String sizes){
  return split(source, Arrays.stream(sizes.split(","))
                    .mapToInt(it -> it.equals("rest") ? -1 : Integer.parseInt(it))
                    .toArray());
}

Then you can use split(String, String) to achieve your ways, for example:

String string = "AAABBB CCDDD    FFGGGHHHI     KKK"; 
String definition = "2,6,3,1,6,7,rest";

String[] results = split(string, definition);
//        ^--- ["AA", "ABBB C", "CDD", "D", "    FF", "GGGHHHI", "     KKK"]

score 0 · Answer 2 · answered Sep 12 '17 at 19:05

0

StringBuilder temp=new StringBuilder("AAABBB CCDDD    FFGGGHHHI     KKK");
System.out.println(temp.substring(0,2));
temp.delete(0,2);
System.out.println(temp.substring(0,6));
temp.delete(0,6);
//it goes like this

Use StringBuilder, everytime you get substring followed by deletion of substring. Make use of substring(int start, int end) method and delete(int start, int end)

answered Sep 12 '17 at 19:05

Rahul Raj

3,197
5
35
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The entire `StringBuilder` manipulation is obsolete, as you can perform `substring` directly on the original string just adapting the offsets instead of deleting content, `String s = "AAABBB CCDDD FFGGGHHHI KKK"; System.out.println(s.substring(0, 2)); System.out.println(s.substring(2, 8));`. You can even print subsequences in the first place, `System.out.append(s, 0, 2).append('\n').append(s, 2, 8).println();`… – Holger Sep 13 '17 at 09:37
yeah, we can use `String`s `substring()` method to print, but I thought OP wanted to perform `substring()` operation on an updated `String`. Since `StringBuilder` is mutable, I used that instead of creating additional `String` variables. – Rahul Raj Sep 13 '17 at 12:28

score 0 · Answer 3 · answered Sep 12 '17 at 19:30

First you made an error in your counting, and this is some code to do your stuff :

public static void main(String[] args) {
    String str = "AAABBB CCDDD    FFGGGHHHI     KKK";
    int[] split = new int[]{2, 6, 3, 1, 6, 7};
    List<String> res = new ArrayList<>();
    StringBuilder temp = new StringBuilder(str);

    for (int i = 0; i < split.length ; i++) {
        res.add(temp.substring(0, split[i]));
        temp.delete(0, split[i]);
    }
    res.add(temp.toString());

    res.forEach(System.out::println);
}

And the output is :

AA         // 2
ABBB C     // 6
CDD        // 3
D          // 1
    FF     // 6
GGGHHHI    // 7
     KKK   // rest

score 0 · Answer 4 · answered Sep 12 '17 at 19:35

That is my version

    String str = "AAABBB CCDDD    FFGGGHHHI     KKK";
    List<Integer> def = Arrays.asList(2,6,3,1,6,7);

    List<String> res = split (str, def);
    int n = res.size();
    for (int i = 0; i < n; i ++) {
        String r = res.get(i);
        if (i + 1 == n) {
            System.out.println("rest: " + r);
        } else {
            System.out.println(r.length() + "   : " + r);
        }
    }

public List<String> split (String pStr, List<Integer> pDef) {
    List<String> ret = new ArrayList<String> ();
    int startStr = 0;
    int startDef = 0;
    while (startStr < pStr.length() && startDef < pDef.size()) {
        int end = startStr + pDef.get(startDef);
        ret.add(pStr.substring(startStr, end));
        startStr = end;
        startDef ++;
    }
    if (startStr < pStr.length()) {
        ret.add(pStr.substring(startStr));
    }
    return ret;
}

Output:

2   : AA
6   : ABBB C
3   : CDD
1   : D
6   :     FF
7   : GGGHHHI
rest:      KKK

Splitting string and instantiating the object

4 Answers4