Java multidimensional Array to string and String to Array

Question

I have array

data[][];

convert to string:

string = Arrays.deepToString(data);

string:

[[1, 1394119227787, 59474093, USD/DKK, true, 0.05, 5.391582, 5.00663, 5.39663, null, null], [1, 1394581174413, 59500543, EUR/JPY, false, 0.05, 142.489381, 145.3, 139.68, null, null],
[1, 1394581174413, 59500543, EUR/JPY, false, 0.05, 142.489381, 145.3, 139.68, null, null],
[1, 1394581174413, 59500543, EUR/JPY, false, 0.05, 142.489381, 145.3, 139.68, null, null]]

and How convert this string back to array?

Answer 1

Try my stringToDeep() method to convert back to Array.

import java.util.*;

public class DeepToArray {

public static void main(String[] args) {

    int row, col;
    row = 2;
    col = 3;
    String[][] in = new String[row][col];

    for (int i = 0; i < row; i++) {
        for (int j = 0; j < col; j++) {
            in[i][j] = i + " " + j;
        }
    }
    String str = Arrays.deepToString(in);

    System.out.println(str);

    String[][] out = stringToDeep(str);

    for (String s2[] : out) {
        for (String s3 : s2) {
            System.out.print(s3 + "  ");
        }
        System.out.println();
    }
}

private static String[][] stringToDeep(String str) {
    int row = 0;
    int col = 0;
    for (int i = 0; i < str.length(); i++) {
        if (str.charAt(i) == '[') {
            row++;
        }
    }
    row--;
    for (int i = 0;; i++) {
        if (str.charAt(i) == ',') {
            col++;
        }
        if (str.charAt(i) == ']') {
            break;
        }
    }
    col++;

    String[][] out = new String[row][col];

    str = str.replaceAll("\\[", "").replaceAll("\\]", "");

    String[] s1 = str.split(", ");

    int j = -1;
    for (int i = 0; i < s1.length; i++) {
        if (i % col == 0) {
            j++;
        }
        out[j][i % col] = s1[i];
        //System.out.println(s1[i] + "\t" + j + "\t" + i % col);
    }
    return out;
}
}

Answer 2

There is no method in the java API that will automatically convert this back to an array. You could write code to do this yourself, but it would be tricky; this format does not escape special characters like the square brackets, or the commas. It might be easier just to use a format which is designed for encoding and decoding arrays, like JSON.