Java Resource File getInputStreamForResource(String s)

Description

Uses getSourceForResource on the passed string and tries to open whatever resource is passed and return the correspondent open input stream.

License

Open Source License

Return

an open input stream or null. No exceptions are thrown.

Declaration

public static InputStream getInputStreamForResource(String s)

Method Source Code

//package com.java2s;
/**/*w  w  w.  j a v a 2s .c o  m*/
 * Copyright 2011 The ARIES Consortium (http://www.ariesonline.org) and
 * www.integratedmodelling.org. 
    
   This file is part of Thinklab.
    
   Thinklab 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.
    
   Thinklab 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 Thinklab.  If not, see <http://www.gnu.org/licenses/>.
 */

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

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

import java.net.MalformedURLException;

import java.net.URL;

public class Main {
    /**
     * Uses getSourceForResource on the passed string and tries to open whatever resource
     * is passed and return the correspondent open input stream.
     * @return an open input stream or null. No exceptions are thrown.
     */
    public static InputStream getInputStreamForResource(String s) {

        InputStream ret = null;

        Object o = getSourceForResource(s);

        if (o != null) {

            if (o instanceof File) {
                try {
                    ret = new FileInputStream((File) o);
                } catch (FileNotFoundException e) {
                }
            } else if (o instanceof URL) {
                try {
                    ret = ((URL) o).openStream();
                } catch (IOException e) {
                }
            }
        }

        return ret;
    }

    /**
     * Analyze the passed string and determine if it specifies an existing file resource
     * or URL. Return the appropriate object, that must be disambiguated using instanceof.
     * Meant to (inelegantly) solve problems coming from file name encodings in primitive
     * OS (e.g. Windows) that cannot be handled properly in file:// URLs. 
     * @return a valid URL, existing file, or null. No exceptions are thrown.
     */
    public static Object getSourceForResource(String s) {

        File f = new File(s);

        if (f.exists())
            return f;

        URL url = null;
        try {
            url = new URL(s);
        } catch (MalformedURLException e) {
        }

        if (url != null)
            return url;

        return null;
    }
}