Java Text File Read Line readLines(File file)

Description

Returns a String containing the contents lines of the file .

License

Open Source License

Parameter

Parameter	Description
file	The file to be read.

Exception

Parameter	Description
IOException	If an I/O error occurs.
NullPointerException	If file is <code>null</code>.

Return

A String containing the contents of the lines, including line-termination characters, or null if the end of the stream has been reached.

Declaration

public static String readLines(File file) throws IOException

Method Source Code

//package com.java2s;
/**// ww  w .  ja  va  2s . c  o  m
 *     Copyright (C) 2013 Contributors
 *
 *     This program is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 *
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program.  If not, see <http://www.gnu.org/licenses/>
 */

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Objects;

public class Main {
    /**
     * Returns a {@link String} containing the contents lines of the {@code file}.
     * 
     * @param file
     *            The file to be read.
     * @return A String containing the contents of the lines, including line-termination characters, or <code>null</code> if the end of the stream has
     *         been reached.
     * @throws IOException
     *             If an I/O error occurs.
     * @throws NullPointerException
     *             If {@code file} is <code>null</code>.
     */
    public static String readLines(File file) throws IOException {
        StringBuilder content = new StringBuilder();
        try (BufferedReader reader = new BufferedReader(new FileReader(Objects.requireNonNull(file)))) {
            for (String line = reader.readLine(); line != null; line = reader.readLine()) {
                content.append(line).append("\n");
            }
        }
        return content.toString();
    }
}