uriutil.java

Light in the box 抓取程序。 使用HttpClient

/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/util/URIUtil.java,v 1.27 2004/05/05 20:34:01 olegk Exp $
 * $Revision: 507321 $
 * $Date: 2007-02-14 01:10:51 +0100 (Wed, 14 Feb 2007) $
 *
 * ====================================================================
 *
 *  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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.commons.httpclient.util;

import java.util.BitSet;

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.net.URLCodec;
import org.apache.commons.httpclient.URI;
import org.apache.commons.httpclient.URIException;

/**
 * The URI escape and character encoding and decoding utility.
 * It's compatible with {@link org.apache.commons.httpclient.HttpURL} rather
 * than {@link org.apache.commons.httpclient.URI}.
 *
 * @author <a href="mailto:[e-mail]">Sung-Gu</a>
 * @version $Revision: 507321 $ $Date: 2002/03/14 15:14:01 
 */
public class URIUtil {

    // ----------------------------------------------------- Instance variables

    protected static final BitSet empty = new BitSet(1);

    // ---------------------------------------------------------- URI utilities

    /**
     * Get the basename of an URI.   It's possibly an empty string.
     *
     * @param uri a string regarded an URI
     * @return the basename string; an empty string if the path ends with slash
     */
    public static String getName(String uri) {
        if (uri == null || uri.length() == 0) { return uri; } 
        String path = URIUtil.getPath(uri);
        int at = path.lastIndexOf("/");
        int to = path.length();
        return (at >= 0) ? path.substring(at + 1, to) : path;
    }


    /**
     * Get the query of an URI.
     *
     * @param uri a string regarded an URI
     * @return the query string; <code>null</code> if empty or undefined
     */
    public static String getQuery(String uri) {
        if (uri == null || uri.length() == 0) { return null; } 
        // consider of net_path
        int at = uri.indexOf("//");
        int from = uri.indexOf(
            "/", 
            at >= 0 ? (uri.lastIndexOf("/", at - 1) >= 0 ? 0 : at + 2) : 0
        );
        // the authority part of URI ignored
        int to = uri.length();
        // reuse the at and from variables to consider the query
        at = uri.indexOf("?", from);
        if (at >= 0) {
            from = at + 1;
        } else {
            return null;
        }
        // check the fragment
        if (uri.lastIndexOf("#") > from) {
            to = uri.lastIndexOf("#");
        }
        // get the path and query.
        return (from < 0 || from == to) ? null : uri.substring(from, to);
    }


    /**
     * Get the path of an URI.
     *
     * @param uri a string regarded an URI
     * @return the path string
     */
    public static String getPath(String uri) {
        if (uri == null) {
            return null;
        } 
        // consider of net_path
        int at = uri.indexOf("//");
        int from = uri.indexOf(
            "/", 
            at >= 0 ? (uri.lastIndexOf("/", at - 1) >= 0 ? 0 : at + 2) : 0
        );
        // the authority part of URI ignored 
        int to = uri.length();
        // check the query
        if (uri.indexOf('?', from) != -1) {
            to = uri.indexOf('?', from);
        }
        // check the fragment
        if (uri.lastIndexOf("#") > from && uri.lastIndexOf("#") < to) {
            to = uri.lastIndexOf("#");
        }
        // get only the path.
        return (from < 0) ? (at >= 0 ? "/" : uri) : uri.substring(from, to);
    }


    /**
     * Get the path and query of an URI.
     *
     * @param uri a string regarded an URI
     * @return the path and query string
     */
    public static String getPathQuery(String uri) {
        if (uri == null) {
            return null;
        } 
        // consider of net_path
        int at = uri.indexOf("//");
        int from = uri.indexOf(
            "/", 
            at >= 0 ? (uri.lastIndexOf("/", at - 1) >= 0 ? 0 : at + 2) : 0
        );
        // the authority part of URI ignored
        int to = uri.length();
        // Ignore the '?' mark so to ignore the query.
        // check the fragment
        if (uri.lastIndexOf("#") > from) {
            to = uri.lastIndexOf("#");
        }
        // get the path and query.
        return (from < 0) ? (at >= 0 ? "/" : uri) : uri.substring(from, to);
    }


    /**
     * Get the path of an URI and its rest part.
     *
     * @param uri a string regarded an URI
     * @return the string from the path part
     */
    public static String getFromPath(String uri) {
        if (uri == null) {
            return null;
        } 
        // consider of net_path
        int at = uri.indexOf("//");
        int from = uri.indexOf(
            "/", 
            at >= 0 ? (uri.lastIndexOf("/", at - 1) >= 0 ? 0 : at + 2) : 0
        );
        // get the path and its rest.
        return (from < 0) ? (at >= 0 ? "/" : uri) : uri.substring(from);
    }

    // ----------------------------------------------------- Encoding utilities

    /**
     * Get the all escaped and encoded string with the default protocl charset.
     * It's the same function to use <code>encode(String unescaped, Bitset
     * empty, URI.getDefaultProtocolCharset())</code>.
     *
     * @param unescaped an unescaped string
     * @return the escaped string
     * 
     * @throws URIException if the default protocol charset is not supported
     *
     * @see URI#getDefaultProtocolCharset
     * @see #encode
     */
    public static String encodeAll(String unescaped) throws URIException {
        return encodeAll(unescaped, URI.getDefaultProtocolCharset());
    }
 

    /**
     * Get the all escaped and encoded string with a given charset.
     * It's the same function to use <code>encode(String unescaped, Bitset
     * empty, String charset)</code>.
     *
     * @param unescaped an unescaped string
     * @param charset the charset
     * @return the escaped string
     * 
     * @throws URIException if the charset is not supported
     * 
     * @see #encode
     */
    public static String encodeAll(String unescaped, String charset)
        throws URIException {

        return encode(unescaped, empty, charset);
    }
  

    /**
     * Escape and encode a string regarded as within the authority component of
     * an URI with the default protocol charset.
     * Within the authority component, the characters ";", ":", "@", "?", and
     * "/" are reserved.
     *
     * @param unescaped an unescaped string
     * @return the escaped string
     * 
     * @throws URIException if the default protocol charset is not supported
     * 
     * @see URI#getDefaultProtocolCharset
     * @see #encode
     */
    public static String encodeWithinAuthority(String unescaped)
        throws URIException {

        return encodeWithinAuthority(unescaped, URI.getDefaultProtocolCharset());
    }


    /**
     * Escape and encode a string regarded as within the authority component of
     * an URI with a given charset.
     * Within the authority component, the characters ";", ":", "@", "?", and
     * "/" are reserved.
     *
     * @param unescaped an unescaped string
     * @param charset the charset
     * @return the escaped string
     * 
     * @throws URIException if the charset is not supported
     * 
     * @see #encode
     */
    public static String encodeWithinAuthority(String unescaped, String charset)
        throws URIException {

        return encode(unescaped, URI.allowed_within_authority, charset);
    }


    /**
     * Escape and encode a string regarded as the path and query components of
     * an URI with the default protocol charset.
     *
     * @param unescaped an unescaped string
     * @return the escaped string
     * 
     * @throws URIException if the default protocol charset is not supported
     * 
     * @see URI#getDefaultProtocolCharset
     * @see #encode
     */
    public static String encodePathQuery(String unescaped) throws URIException {
        return encodePathQuery(unescaped, URI.getDefaultProtocolCharset());
    }


    /**
     * Escape and encode a string regarded as the path and query components of
     * an URI with a given charset.
     *
     * @param unescaped an unescaped string
     * @param charset the charset
     * @return the escaped string
     * 
     * @throws URIException if the charset is not supported
     * 
     * @see #encode
     */
    public static String encodePathQuery(String unescaped, String charset)
        throws URIException {

        int at = unescaped.indexOf('?');
        if (at < 0) {
            return encode(unescaped, URI.allowed_abs_path, charset);
        }
        // else
        return  encode(unescaped.substring(0, at), URI.allowed_abs_path, charset)
            + '?' + encode(unescaped.substring(at + 1), URI.allowed_query, charset);
    }


    /**
     * Escape and encode a string regarded as within the path component of an
     * URI with the default protocol charset.
     * The path may consist of a sequence of path segments separated by a
     * single slash "/" character.  Within a path segment, the characters
     * "/", ";", "=", and "?" are reserved.
     *
     * @param unescaped an unescaped string
     * @return the escaped string
     * 
     * @throws URIException if the default protocol charset is not supported
     * 
     * @see URI#getDefaultProtocolCharset
     * @see #encode
     */
    public static String encodeWithinPath(String unescaped)
        throws URIException {

        return encodeWithinPath(unescaped, URI.getDefaultProtocolCharset());
    }


    /**
     * Escape and encode a string regarded as within the path component of an
     * URI with a given charset.