Java InputStreamReader Read readFile(String f, String delim)

Description

read File

License

Open Source License

Declaration

public static String[][] readFile(String f, String delim) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.io.BufferedReader;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileInputStream;

import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.IOException;

import java.util.ArrayList;

public class Main {
    public static String[][] readFile(String f, int num_cols) {
        return readFile(f, "\t", num_cols);
    }//from w w  w  . j  av a2 s. c  o m

    public static String[][] readFile(String f, String delim) {
        return readFile(f, delim, 0);
    }

    /**
     * 
     * @param f file from where the array will be read
     * @param delim delimiter used
     * @param num_cols number of columns of the array
     * @return
     */
    public static String[][] readFile(String f, String delim, int num_cols) {
        String[][] a = new String[0][];
        try {
            a = readStream(new FileInputStream(new File(f)), delim, num_cols);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        return a;
    }

    public static String[][] readStream(InputStream os, int num_cols) {
        return readStream(os, "\t", num_cols);
    }

    public static String[][] readStream(InputStream os, String delim) {
        return readStream(os, delim, 0);
    }

    /**
     * 
     * @param os The output stream where the array will be stored
     * @param a array to be stored
     * @param delim delimiter used
     * @param num_cols number of array elements in each line (row) of the stream
     */
    public static String[][] readStream(InputStream os, String delim, int num_cols) {
        String[][] a = new String[0][];
        ArrayList<String[]> al = new ArrayList<String[]>();
        BufferedReader br = null;

        try {

            InputStreamReader osr = new InputStreamReader(os);
            br = new BufferedReader(osr);

            if (num_cols > 0) {
                String str;
                int count = 0;
                String[] leftover = new String[0];
                while ((str = br.readLine()) != null) {
                    String[] tokens = str.split(delim);
                    String[] els = concat_strarrays(leftover, tokens);
                    count = els.length;

                    int quot = count / num_cols;

                    int ind = 0;
                    if (quot != 0) {
                        for (int i = 0; i < quot; i++) {
                            String[] curr_els = new String[num_cols];
                            for (int j = 0; j < num_cols; j++) {
                                curr_els[j] = els[ind++];
                            }
                            al.add(curr_els);
                        }
                        count %= num_cols;
                    }

                    leftover = new String[count];
                    for (int k = 0; k < count; k++)
                        leftover[k] = els[ind++];
                }
                al.add(leftover);
            }

            else if (num_cols == 0) {
                String str;
                while ((str = br.readLine()) != null) {
                    String[] tokens = str.split(delim);
                    al.add(tokens);
                }
            }

            else if (num_cols == -1) {
                ArrayList<String> temp_list = new ArrayList<String>();
                String str;
                while ((str = br.readLine()) != null) {
                    String[] tokens = str.split(delim);
                    for (int i = 0; i < tokens.length; i++) {
                        temp_list.add(tokens[i]);
                    }
                }
                al.add(temp_list.toArray(new String[0]));
            } else {
                throw new IllegalArgumentException(
                        "Invalid value for num_cols. The valid values are -1 (one row), 0 (as they are on the file), k (columns in each row).");
            }

            a = new String[al.size()][];
            for (int i = 0; i < a.length; i++) {
                a[i] = al.get(i);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return a;
    }

    private static String[] concat_strarrays(String[] ar1, String[] ar2) {
        String[] ar = new String[ar1.length + ar2.length];
        int count = 0;
        for (int i = 0; i < ar1.length; i++) {
            ar[count++] = ar1[i];
        }
        for (int i = 0; i < ar2.length; i++) {
            ar[count++] = ar2[i];
        }
        return ar;
    }
}

Related

1. readFile(InputStream location)
2. readFile(InputStream stream, StringBuilder builder)
3. readFile(Reader simpleReader)
4. readFile(String aFile)
5. readFile(String f)
6. readFile(String file)
7. readFile(String file)
8. readFile(String file)
9. readFile(String file)