Java URI to File Name getFilename(final URI uri)

Description

Gets the file name of a given URI

License

Apache License

Parameter

Parameter	Description
uri	the input URI object

Exception

Parameter	Description
MalformedURLException	if the URI is invalid or null

Return

the file name part of the URI

Declaration

public static String getFilename(final URI uri) throws MalformedURLException 

Method Source Code

//package com.java2s;
/**//w w  w . j ava 2s.c o  m
   Copyright 2012 Otavio Rodolfo Piske
    
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at
    
   http://www.apache.org/licenses/LICENSE-2.0
    
   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
 */

import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;

public class Main {
    public static final String URL_SEPARATOR = "/";
    private static final String PARAMETERS_START = "?";

    /**
     * Gets the file name of a given URI
     * 
     * @param uri
     *            the input URI object
     * @return the file name part of the URI
     * @throws MalformedURLException
     *             if the URI is invalid or null
     */
    public static String getFilename(final URI uri) throws MalformedURLException {
        URL url;

        if (uri == null) {
            throw new MalformedURLException("The input URL 'null' is not valid");
        }

        url = uri.toURL();

        String filePath = url.getFile();
        int lastIndex = filePath.lastIndexOf(URL_SEPARATOR);

        String filenameWithParameters = filePath.substring(lastIndex + 1);

        return removeParametersFromName(filenameWithParameters);
    }

    /**
     * @param uri
     *            the input URI
     * @return the file name part of the URI
     * @throws URISyntaxException
     *             if the syntax is invalid
     * @throws MalformedURLException
     *             if the URI is invalid or null
     */
    public static String getFilename(String uri) throws MalformedURLException, URISyntaxException {
        return getFilename(new URI(uri));
    }

    /**
     * Given a filename with (mostly) standard parameters (ie.: 
     * abc.php?c=123&d=456)
     * it will remove the parameters and return only the file name
     * @param filename the input file name
     * @return the file name without parameters
     * TODO: this method is very naive. We need a better implementation
     */
    public static String removeParametersFromName(final String filename) {
        if (!filename.contains(PARAMETERS_START)) {
            return filename;
        }

        int firstParameter = filename.indexOf(PARAMETERS_START);

        return filename.substring(0, firstParameter);
    }
}

Related

1. getFile(URI uri)
2. getFile(URI uri)
3. getFile(URI uri)
4. getFileByPathOrURI(String path)
5. getFileFromURIList(URI[] uris, String fileName)
6. getFilename(final URI uri)
7. getFileName(URI path)
8. getFileName(URI uri)
9. getFileName(URI uri)