UriAccessor.java

/*
 * Copyright 2010-2011 Ning, Inc.
 *
 * Ning licenses this file to you 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.
 */

package com.ning.billing.util.config;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Scanner;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.io.Resources;

public class UriAccessor {

    private final static Logger log = LoggerFactory.getLogger(UriAccessor.class);

    private static final String URI_SCHEME_FOR_CLASSPATH = "jar";
    private static final String URI_SCHEME_FOR_FILE = "file";

    public static InputStream accessUri(String uri)  throws IOException, URISyntaxException {
        return accessUri(new URI(uri));
    }

    public static InputStream accessUri(URI uri) throws IOException, URISyntaxException {
        String scheme = uri.getScheme();
        URL url = null;
        if (scheme == null) {
            uri = new URI(Resources.getResource(uri.toString()).toExternalForm());
        } else if (scheme.equals(URI_SCHEME_FOR_CLASSPATH)) {
            return UriAccessor.class.getResourceAsStream(uri.getPath());
        } else if (scheme.equals(URI_SCHEME_FOR_FILE) &&
                !uri.getSchemeSpecificPart().startsWith("/")) { // interpret URIs of this form as relative path uris
            url = new File(uri.getSchemeSpecificPart()).toURI().toURL();
        } else {
            throw new RuntimeException("");
        }
        url = uri.toURL();
        return url.openConnection().getInputStream();
    }

    public static String accessUriAsString(String uri)  throws IOException, URISyntaxException {
        return accessUriAsString(new URI(uri));
    }

    public static String accessUriAsString(URI uri) throws IOException,  URISyntaxException {
        InputStream stream = accessUri(uri);
        return new Scanner(stream).useDelimiter("\\A").next();
    }
}