Java URL Load readTextFile(final URL resource)

Description

Reads a text file (UTF-8 encoding) from the specified resource.

License

Open Source License

Parameter

Parameter	Description
resource	The resource from which to read the text.

Exception

Parameter	Description
IOException	When read fails.

Return

The text.

Declaration

public static String readTextFile(final URL resource) throws IOException 

Method Source Code

//package com.java2s;
/*//from  w  ww  .j  a va2 s.  c om
 * Copyright (C) 2011 Klaus Reimer <k@ailis.de>
 * See LICENSE.md for licensing information.
 */

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;

public class Main {
    /**
     * Reads a text file (UTF-8 encoding) from the specified resource.
     *
     * @param resource
     *            The resource from which to read the text.
     * @return The text.
     * @throws IOException
     *             When read fails.
     */
    public static String readTextFile(final URL resource) throws IOException {
        if (resource == null)
            throw new IOException("Resource not found");
        try (final InputStream stream = resource.openStream()) {
            return readTextFile(stream);
        }
    }

    /**
     * Reads a text file (UTF-8 encoding) from the specified stream.
     *
     * @param resource
     *            The resource from which to read the text.
     * @return The text.
     * @throws IOException
     *             When read fails.
     */
    public static String readTextFile(final InputStream resource) throws IOException {
        return new String(readFile(resource), "UTF-8");
    }

    /**
     * Reads data from a file.
     *
     * @param filename
     *            The filename. Can be '-' for reading from stdin.
     * @return data The read data.
     * @throws IOException
     *             When read fails.
     */
    public static byte[] readFile(final String filename) throws IOException {
        if (filename.equals("-"))
            return readFile(System.in);

        try (final InputStream stream = new FileInputStream(filename)) {
            return readFile(stream);
        }
    }

    /**
     * Reads data from a stream.
     *
     * @param stream
     *            The stream from which to read the data.
     * @return data The read data.
     * @throws IOException
     *             When read fails.
     */
    public static byte[] readFile(final InputStream stream) throws IOException {
        final ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        copy(stream, bytes);
        return bytes.toByteArray();
    }

    /**
     * Copies data from input stream to output stream.
     *
     * @param input
     *            The input stream
     * @param output
     *            The output stream
     * @throws IOException
     *             When copying fails.
     */
    public static void copy(final InputStream input, final OutputStream output) throws IOException {
        final byte[] buffer = new byte[8192];
        int read;
        while ((read = input.read(buffer)) != -1) {
            output.write(buffer, 0, read);
        }
    }
}

Related

1. readStopwordsURL(URL url, boolean lowercase)
2. readStringFromUrl(URL url)
3. readStringFromURL(URL url)
4. readText(final URL url)
5. readText(final URL url)
6. readTextFileAtUrl(final URL url)
7. readTextFromUrl(URL url)
8. readTextStream(URL url, String encoding)
9. readTextURL(URL url)