URLUtil.java

/*
 * Copyright 2008-2010 the T2 Project ant the Others.
 *
 * 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 org.t2framework.confeito.util;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;

/**
 * <#if locale="en">
 * <p>
 * URL utility class.
 * 
 * </p>
 * <#else>
 * <p>
 * 
 * </p>
 * </#if>
 * 
 * @author shot
 * 
 */
public class URLUtil {

	protected static final Map<String, String> CANONICAL_PROTOCOLS = new HashMap<String, String>();

	protected static final String VALID_SCHEME_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789+.-";

	static {
		CANONICAL_PROTOCOLS.put("wsjar", "jar"); // for WebSphere
		CANONICAL_PROTOCOLS.put("vfszip", "zip"); // for JBoss5
	}

	/**
	 * <#if locale="en">
	 * <p>
	 * no instantiation.
	 * </p>
	 * <#else>
	 * <p>
	 * 
	 * </p>
	 * </#if>
	 */
	private URLUtil() {
	}

	/**
	 * <#if locale="en">
	 * <p>
	 * Get {@link URLConnection} from {@link URL}.
	 * 
	 * </p>
	 * <#else>
	 * <p>
	 * 
	 * </p>
	 * </#if>
	 * 
	 * @param url
	 * @return
	 * @throws IORuntimeException
	 */
	public static URLConnection openConnection(URL url) {
		try {
			URLConnection connection = url.openConnection();
			connection.setUseCaches(false);
			return connection;
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * <#if locale="en">
	 * <p>
	 * Get {@link InputStream} from {@link URL}.
	 * 
	 * </p>
	 * <#else>
	 * <p>
	 * 
	 * </p>
	 * </#if>
	 * 
	 * @param url
	 * @return
	 * @throws IORuntimeException
	 */
	public static InputStream openStream(URL url) {
		try {
			URLConnection connection = url.openConnection();
			connection.setUseCaches(false);
			return connection.getInputStream();
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * <#if locale="en">
	 * <p>
	 * Create {@link URL} from the string.
	 * 
	 * </p>
	 * <#else>
	 * <p>
	 * 
	 * </p>
	 * </#if>
	 * 
	 * @param spec
	 * @return
	 * @throws IORuntimeException
	 */
	public static URL create(String spec) {
		try {
			return new URL(spec);
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * <#if locale="en">
	 * <p>
	 * Create {@link URL} from context url and spec.
	 * 
	 * </p>
	 * <#else>
	 * <p>
	 * 
	 * </p>
	 * </#if>
	 * 
	 * @param context
	 * @param spec
	 * @return url
	 * @throws IORuntimeException
	 */
	public static URL create(URL context, String spec) {
		try {
			return new URL(context, spec);
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * <#if locale="en">
	 * <p>
	 * Encode string with the encode character.
	 * 
	 * </p>
	 * <#else>
	 * <p>
	 * 
	 * </p>
	 * </#if>
	 * 
	 * @param s
	 * @param enc
	 * @return
	 * @throws IORuntimeException
	 */
	public static String encode(final String s, final String enc) {
		try {
			return URLEncoder.encode(s, enc);
		} catch (final UnsupportedEncodingException e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * <#if locale="en">
	 * <p>
	 * Decode string with the encode character.
	 * 
	 * </p>
	 * <#else>
	 * <p>
	 * 
	 * </p>
	 * </#if>
	 * 
	 * @param s
	 * @param enc
	 * @return
	 * @throws IORuntimeException
	 */
	public static String decode(final String s, final String enc) {
		try {
			return URLDecoder.decode(s, enc);
		} catch (final UnsupportedEncodingException e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * <#if locale="en">
	 * <p>
	 * Convert protocol to canonical protocol.This method is used for
	 * application server dependent protocol like wsjar as jar for WebSphere.
	 * 
	 * </p>
	 * <#else>
	 * <p>
	 * 
	 * </p>
	 * </#if>
	 * 
	 * @param protocol
	 * @return
	 */
	public static String toCanonicalProtocol(final String protocol) {
		final String canonicalProtocol = CANONICAL_PROTOCOLS.get(protocol);
		if (canonicalProtocol != null) {
			return canonicalProtocol;
		}
		return protocol;
	}

	/**
	 * <#if locale="en">
	 * <p>
	 * Return the url is absolute url or not.
	 * 
	 * </p>
	 * <#else>
	 * <p>
	 * 
	 * </p>
	 * </#if>
	 * 
	 * @param url
	 * @return
	 */
	public static boolean isAbsoluteUrl(String url) {
		if (url == null) {
			return false;
		}
		int colonPos;
		if ((colonPos = url.indexOf(":")) == -1) {
			return false;
		}
		for (int i = 0; i < colonPos; i++) {
			if (VALID_SCHEME_CHARS.indexOf(url.charAt(i)) == -1) {
				return false;
			}
		}
		return true;
	}

	public static URL toUrl(File file) {
		Assertion.notNull(file);
		try {
			return file.toURI().toURL();
		} catch (MalformedURLException e) {
			throw new RuntimeException(e);
		}
	}

}