ClasspathResource.java

/**
 * Copyright 2013-2016 Guoqiang Chen, Shanghai, China. All rights reserved.
 *
 *   Author: Guoqiang Chen
 *    Email: subchen@gmail.com
 *   WebURL: https://github.com/subchen
 *
 * 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.
 */
package jetbrick.io.resource;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

import jetbrick.util.ClassLoaderUtils;
import jetbrick.util.JdkUtils;
import jetbrick.util.StringUtils;
import jetbrick.util.Validate;

public final class ClasspathResource extends AbstractResource {
    private final URL url;
    private final String path;

    public ClasspathResource(String path) {
        this(path, null);
    }

    public ClasspathResource(String path, ClassLoader loader) {
        Validate.notNull(path);

        path = StringUtils.removeStart(path, "/");
        this.path = path;
        this.relativePathName = path;

        if (loader == null) {
            loader = ClassLoaderUtils.getDefault();
        }
        if (loader == null) {
            this.url = ClassLoader.getSystemResource(path);
        } else {
            this.url = loader.getResource(path);
        }
    }

    @Override
    public InputStream openStream() throws ResourceNotFoundException {
        if (url == null) {
            throw new ResourceNotFoundException(path);
        }
        try {
            return url.openStream();
        } catch (IOException e) {
            throw new IllegalStateException(e);
        }
    }

    @Override
    public URL getURL() {
        return url;
    }

    @Override
    public boolean exist() {
        return url != null;
    }

    @Override
    public boolean isDirectory() {
        return path.endsWith("/");
    }

    @Override
    public boolean isFile() {
        return !path.endsWith("/");
    }

    @Override
    public long length() {
        if (url == null) {
            return -1;
        }
        try {
            if (JdkUtils.IS_AT_LEAST_JAVA_7) {
                return url.openConnection().getContentLengthLong();
            } else {
                return url.openConnection().getContentLength();
            }
        } catch (IOException e) {
            throw new IllegalStateException(e);
        }
    }

    @Override
    public long lastModified() {
        if (url == null) {
            return 0;
        }

        long lastModified = 0;

        String protocol = url.getProtocol();
        if (Resource.URL_PROTOCOL_FILE.equals(protocol)) {
            lastModified = new File(url.getFile()).lastModified();
        } else if (Resource.URL_PROTOCOL_JAR.equals(protocol) || Resource.URL_PROTOCOL_ZIP.equals(protocol)) {
            String file = url.getFile();
            if (file.startsWith(Resource.URL_PREFIX_FILE)) {
                file = file.substring(Resource.URL_PREFIX_FILE.length());
            }
            int pos = file.indexOf(Resource.URL_SEPARATOR_JAR);
            if (pos != -1) {
                file = file.substring(0, pos);
            }
            lastModified = new File(file).lastModified();
        }

        if (lastModified <= 0) {
            try {
                lastModified = url.openConnection().getLastModified();
            } catch (IOException e) {
                throw new IllegalStateException(e);
            }
        }

        // If cannot get lastModified from an exists ClasspathResource, should alwyas return 1.
        if (lastModified <= 0) {
            lastModified = 1;
        }
        return lastModified;
    }

    @Override
    public String toString() {
        return URL_PREFIX_CLASSPATH + path;
    }
}