com.taobao.metamorphosis.utils.ResourceUtils Maven / Gradle / Ivy

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/*
 * (C) 2007-2012 Alibaba Group Holding Limited.
 * 
 * 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.
 * Authors:
 *   wuhua  , boyan 
 */
package com.taobao.metamorphosis.utils;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.util.Properties;


/**
 * 
 * @author boyan
 * @date 2010-5-4
 */
public class ResourceUtils extends Object {

    /** */
    /**
     * Returns the URL of the resource on the classpath
     * 
     * @param resource
     *            The resource to find
     * @throws IOException
     *             If the resource cannot be found or read
     * @return The resource
     */
    public static URL getResourceURL(String resource) throws IOException {
        URL url = null;
        ClassLoader loader = ResourceUtils.class.getClassLoader();
        if (loader != null) {
            url = loader.getResource(resource);
        }
        if (url == null) {
            url = ClassLoader.getSystemResource(resource);
        }
        if (url == null) {
            throw new IOException("Could not find resource " + resource);
        }
        return url;
    }


    /** */
    /**
     * Returns the URL of the resource on the classpath
     * 
     * @param loader
     *            The classloader used to load the resource
     * @param resource
     *            The resource to find
     * @throws IOException
     *             If the resource cannot be found or read
     * @return The resource
     */
    public static URL getResourceURL(ClassLoader loader, String resource) throws IOException {
        URL url = null;
        if (loader != null) {
            url = loader.getResource(resource);
        }
        if (url == null) {
            url = ClassLoader.getSystemResource(resource);
        }
        if (url == null) {
            throw new IOException("Could not find resource " + resource);
        }
        return url;
    }


    /** */
    /**
     * Returns a resource on the classpath as a Stream object
     * 
     * @param resource
     *            The resource to find
     * @throws IOException
     *             If the resource cannot be found or read
     * @return The resource
     */
    public static InputStream getResourceAsStream(String resource) throws IOException {
        InputStream in = null;
        ClassLoader loader = ResourceUtils.class.getClassLoader();
        if (loader != null) {
            in = loader.getResourceAsStream(resource);
        }
        if (in == null) {
            in = ClassLoader.getSystemResourceAsStream(resource);
        }
        if (in == null) {
            throw new IOException("Could not find resource " + resource);
        }
        return in;
    }


    /** */
    /**
     * Returns a resource on the classpath as a Stream object
     * 
     * @param loader
     *            The classloader used to load the resource
     * @param resource
     *            The resource to find
     * @throws IOException
     *             If the resource cannot be found or read
     * @return The resource
     */
    public static InputStream getResourceAsStream(ClassLoader loader, String resource) throws IOException {
        InputStream in = null;
        if (loader != null) {
            in = loader.getResourceAsStream(resource);
        }
        if (in == null) {
            in = ClassLoader.getSystemResourceAsStream(resource);
        }
        if (in == null) {
            throw new IOException("Could not find resource " + resource);
        }
        return in;
    }


    /** */
    /**
     * Returns a resource on the classpath as a Properties object
     * 
     * @param resource
     *            The resource to find
     * @throws IOException
     *             If the resource cannot be found or read
     * @return The resource
     */
    public static Properties getResourceAsProperties(String resource) throws IOException {
        Properties props = new Properties();
        InputStream in = null;
        String propfile = resource;
        in = getResourceAsStream(propfile);
        props.load(in);
        in.close();
        return props;
    }


    /** */
    /**
     * Returns a resource on the classpath as a Properties object
     * 
     * @param loader
     *            The classloader used to load the resource
     * @param resource
     *            The resource to find
     * @throws IOException
     *             If the resource cannot be found or read
     * @return The resource
     */
    public static Properties getResourceAsProperties(ClassLoader loader, String resource) throws IOException {
        Properties props = new Properties();
        InputStream in = null;
        String propfile = resource;
        in = getResourceAsStream(loader, propfile);
        props.load(in);
        in.close();
        return props;
    }


    /** */
    /**
     * Returns a resource on the classpath as a Reader object
     * 
     * @param resource
     *            The resource to find
     * @throws IOException
     *             If the resource cannot be found or read
     * @return The resource
     */
    public static InputStreamReader getResourceAsReader(String resource) throws IOException {
        return new InputStreamReader(getResourceAsStream(resource));
    }


    /** */
    /**
     * Returns a resource on the classpath as a Reader object
     * 
     * @param loader
     *            The classloader used to load the resource
     * @param resource
     *            The resource to find
     * @throws IOException
     *             If the resource cannot be found or read
     * @return The resource
     */
    public static Reader getResourceAsReader(ClassLoader loader, String resource) throws IOException {
        return new InputStreamReader(getResourceAsStream(loader, resource));
    }


    /** */
    /**
     * Returns a resource on the classpath as a File object
     * 
     * @param resource
     *            The resource to find
     * @throws IOException
     *             If the resource cannot be found or read
     * @return The resource
     */
    public static File getResourceAsFile(String resource) throws IOException {
        return new File(getResourceURL(resource).getFile());
    }


    /** */
    /**
     * Returns a resource on the classpath as a File object
     * 
     * @param loader
     *            The classloader used to load the resource
     * @param resource
     *            The resource to find
     * @throws IOException
     *             If the resource cannot be found or read
     * @return The resource
     */
    public static File getResourceAsFile(ClassLoader loader, String resource) throws IOException {
        return new File(getResourceURL(loader, resource).getFile());
    }

}