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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.alipay.sofa.common.utils;

import java.io.File;
import java.io.FileNotFoundException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;

/**
 * @author qilong.zql
 * @author Juergen Hoeller
 * @since 1.0.17
 */
public class ResourceUtil {

    /** URL protocol for a file in the file system: "file" */
    public static final String URL_PROTOCOL_FILE = "file";

    /**
     * Resolve the given resource URL to a {@code java.io.File},
     * i.e. to a file in the file system.
     * @param resourceUrl the resource URL to resolve
     * @return a corresponding File object
     * @throws FileNotFoundException if the URL cannot be resolved to
     * a file in the file system
     */
    public static File getFile(URL resourceUrl) throws FileNotFoundException {
        return getFile(resourceUrl, "URL");
    }

    /**
     * Resolve the given resource URL to a {@code java.io.File},
     * i.e. to a file in the file system.
     * @param resourceUrl the resource URL to resolve
     * @param description a description of the original resource that
     * the URL was created for (for example, a class path location)
     * @return a corresponding File object
     * @throws FileNotFoundException if the URL cannot be resolved to
     * a file in the file system
     */
    public static File getFile(URL resourceUrl, String description) throws FileNotFoundException {
        AssertUtil.notNull(resourceUrl, "Resource URL must not be null");
        if (!URL_PROTOCOL_FILE.equals(resourceUrl.getProtocol())) {
            throw new FileNotFoundException(description
                                            + " cannot be resolved to absolute file path "
                                            + "because it does not reside in the file system: "
                                            + resourceUrl);
        }
        try {
            return new File(toURI(resourceUrl).getSchemeSpecificPart());
        } catch (URISyntaxException ex) {
            // Fallback for URLs that are not valid URIs (should hardly ever happen).
            return new File(resourceUrl.getFile());
        }
    }

    /**
     * Create a URI instance for the given URL,
     * replacing spaces with "%20" URI encoding first.
     * @param url the URL to convert into a URI instance
     * @return the URI instance
     * @throws URISyntaxException if the URL wasn't a valid URI
     * @see java.net.URL#toURI()
     */
    public static URI toURI(URL url) throws URISyntaxException {
        return toURI(url.toString());
    }

    /**
     * Create a URI instance for the given location String,
     * replacing spaces with "%20" URI encoding first.
     * @param location the location String to convert into a URI instance
     * @return the URI instance
     * @throws URISyntaxException if the location wasn't a valid URI
     */
    public static URI toURI(String location) throws URISyntaxException {
        return new URI(StringUtil.replace(location, " ", "%20"));
    }

}