Java Resource Get readToString(final Class nearClass, final String resource)

Description

Returns text content read from the file located near specified class.

License

Open Source License

Parameter

Parameter	Description
nearClass	class near which text file is located
resource	text file location

Return

text file content

Declaration

public static String readToString(final Class nearClass, final String resource) 

Method Source Code

//package com.java2s;
/*//w w w. ja  v  a  2s .  c  o m
 * This file is part of WebLookAndFeel library.
 *
 * WebLookAndFeel library 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.
 *
 * WebLookAndFeel library 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 WebLookAndFeel library.  If not, see <http://www.gnu.org/licenses/>.
 */

import java.io.File;

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

import java.io.Reader;

import java.net.URL;

import java.util.HashMap;

import java.util.Map;

public class Main {
    /**
     * Buffer size for text reader.
     */
    private static final int TEXT_BUFFER_SIZE = 65536;
    /**
     * Cache for "isFile" method result.
     */
    private static final Map<String, Boolean> isFileCache = new HashMap<String, Boolean>();

    /**
     * Returns text content read from the file located near specified class.
     *
     * @param nearClass
     *            class near which text file is located
     * @param resource
     *            text file location
     * @return text file content
     */
    public static String readToString(final Class nearClass, final String resource) {
        try {
            return readToString(nearClass.getResourceAsStream(resource));
        } catch (final Throwable e) {
            return null;
        }
    }

    /**
     * Returns text content read from the file at the specified url.
     *
     * @param url
     *            text file url
     * @return text file content
     */
    public static String readToString(final URL url) {
        try {
            return readToString(url.openConnection().getInputStream());
        } catch (final Throwable e) {
            return null;
        }
    }

    /**
     * Returns text content read from the input stream.
     *
     * @param inputStream
     *            text content input stream
     * @return text content
     */
    public static String readToString(final InputStream inputStream) {
        try {
            if (inputStream != null) {
                return readToString(new InputStreamReader(inputStream, "UTF-8"));
            } else {
                return null;
            }
        } catch (final Throwable e) {
            return null;
        } finally {
            try {
                inputStream.close();
            } catch (final IOException e) {
                // Ignore this exception
            }
        }
    }

    /**
     * Returns text content read from the specified file.
     *
     * @param file
     *            file to read
     * @return text file content
     */
    public static String readToString(final File file) {
        try {
            if (file != null && file.exists() && file.isFile()) {
                return readToString(new FileReader(file));
            } else {
                return null;
            }
        } catch (final Throwable e) {
            return null;
        }
    }

    /**
     * Returns text content read from the specified reader.
     *
     * @param reader
     *            text content reader
     * @return text content
     */
    public static String readToString(final Reader reader) {
        try {
            if (reader == null) {
                return "";
            }
            int charsRead;
            final char[] buffer = new char[TEXT_BUFFER_SIZE];
            final StringBuilder sb = new StringBuilder();
            while ((charsRead = reader.read(buffer, 0, TEXT_BUFFER_SIZE)) != -1) {
                sb.append(buffer, 0, charsRead);
            }
            return sb.toString();
        } catch (final Throwable e) {
            return "";
        } finally {
            try {
                reader.close();
            } catch (final IOException e) {
                // Ignore this exception
            }
        }
    }

    /**
     * Returns whether the specified file is actually a file (and not a
     * directory, disk or some system folder) or not.
     *
     * @param file
     *            file to process
     * @return true if the specified file is actually a file, false otherwise
     */
    public static boolean isFile(final File file) {
        if (file == null) {
            return false;
        } else if (isFileCache.containsKey(file.getAbsolutePath())) {
            return isFileCache.get(file.getAbsolutePath());
        } else {
            final boolean isFile = file.isFile();
            isFileCache.put(file.getAbsolutePath(), isFile);
            return isFile;
        }
    }
}

Related

1. getResourceString(String key, Object... args)
2. loadResource(Class contextClass, String resourceName)
3. loadResource(final String name)
4. loadResource(final String s)
5. readResource(String resource, Class c)
6. readToString(final Class nearClass, final String resource, final String encoding)