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*
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*
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* please contact info@exolab.org.
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* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Intalio, Inc. Exolab is a registered
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*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
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* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 2002-2003 (C) Intalio, Inc. All Rights Reserved.
*
* $Id$
*/
package org.exolab.castor.net.util;
import java.io.*;
import java.net.URL;
import java.net.MalformedURLException;
import java.util.Stack;
import java.util.StringTokenizer;
/**
* A utility class for URI handling
*
* @author <a href="mailto:kvisco-at-intalio.com">Keith Visco</a>
**/
public class URIUtils {
/**
* the File protocol
**/
private static final String FILE_PROTOCOL_PREFIX = "file:///";
/**
* the path separator for an URI
*/
private static final char HREF_PATH_SEP = '/';
/**
* the path separate for a URL as a String
*/
private static final String URL_PATH_SEP_STR = "/";
/**
* The current directory designator
*/
private static final String CURRENT_DIR_OP = ".";
/**
* The parent directory designator
*/
private static final String PARENT_DIR_OP = "..";
/**
* Returns an InputStream for the file represented by the href
* argument
* @param href the href of the file to get the input stream for.
* @param documentBase the document base of the href argument, if it
* is a relative href
* set documentBase to null if there is none.
* @return an InputStream to the desired resource
* @throws java.io.FileNotFoundException when the file could not be
* found
* @throws java.io.IOException
*/
public static InputStream getInputStream(String href, String documentBase)
throws java.io.FileNotFoundException, java.io.IOException
{
//-- check for absolute url
URL url = null;
try {
url = new URL(href);
return url.openStream();
}
catch (MalformedURLException muex) {}
//-- join document base + href
String xHref = null;
if ((documentBase != null) && (documentBase.length() > 0)) {
int idx = documentBase.lastIndexOf(HREF_PATH_SEP);
if (idx == (documentBase.length()-1))
xHref = documentBase+href;
else
xHref = documentBase+HREF_PATH_SEP+href;
}
else xHref = href;
//-- check for relative url
try {
url = new URL(xHref);
return url.openStream();
}
catch(MalformedURLException muex) {}
// Try local files
File iFile = new File(href);
if (iFile.isAbsolute()) return new FileInputStream(iFile);
iFile = new File(xHref);
return new FileInputStream(iFile);
} //-- getInputStream
/**
* Returns a Reader for the file represented by the href
* argument
* @param href the href of the file to get the input stream for.
* @param documentBase the document base of the href argument, if it
* is a relative href
* set documentBase to null if there is none.
* @return an InputStream to the desired resource
* @exception java.io.FileNotFoundException when the file could not be
* found
**/
public static Reader getReader(String href, String documentBase)
throws java.io.FileNotFoundException, java.io.IOException
{
InputStream is = getInputStream(href, documentBase);
return new InputStreamReader(is);
} //-- getReader
/**
* Returns the document base of the href argument
* @return the document base of the given href
**/
public static String getDocumentBase(String href) {
String docBase = "";
if (href == null) return docBase;
int idx = -1;
//-- check for URL
try {
//-- try to create a new URL and see if MalformedURLExcetion is
//-- ever thrown
new URL(href);
idx = href.lastIndexOf(HREF_PATH_SEP);
}
catch(MalformedURLException muex) {
//-- The following contains a fix from Shane Hathaway
//-- to handle the case when both "\" and "/" appear in filename
int idx2 = href.lastIndexOf(HREF_PATH_SEP);
idx = href.lastIndexOf(File.separator);
if (idx2 > idx) idx = idx2;
}
if (idx >= 0) docBase = href.substring(0,idx);
return docBase;
} //-- getDocumentBase
/**
* Returns the relative URI of the href argument
*
* @return the relative URI the given href
**/
public static String getRelativeURI(String href) {
if (href == null) return href;
int idx = -1;
//-- check for URL
try {
//-- try to create a new URL and see if MalformedURLExcetion is
//-- ever thrown
new URL(href);
idx = href.lastIndexOf(HREF_PATH_SEP);
}
catch(MalformedURLException muex) {
//-- The following contains a fix from Shane Hathaway
//-- to handle the case when both "\" and "/" appear in filename
int idx2 = href.lastIndexOf(HREF_PATH_SEP);
idx = href.lastIndexOf(File.separator);
if (idx2 > idx) idx = idx2;
}
if (idx >= 0)
return href.substring(idx+1);
return href;
} //-- getRelativeURI
/**
* This method removes "." or ".." from absolute URL.
* I needed this method because the JDK doesn't do this
* automatically when creating URLs.
*
* @param absoluteURL the absolute URI to normalize
*/
public static String normalize(String absoluteURL)
throws MalformedURLException
{
if (absoluteURL == null) return absoluteURL;
if (absoluteURL.indexOf('.') < 0) return absoluteURL;
//-- Note: using StringTokenizer and Stacks
//-- is not very efficient, this may need
//-- some optimizing
Stack tokens = new Stack();
StringTokenizer st = new StringTokenizer(absoluteURL, URL_PATH_SEP_STR, true);
String last = null;
while (st.hasMoreTokens()) {
String token = st.nextToken();
if (URL_PATH_SEP_STR.equals(token)) {
if (URL_PATH_SEP_STR.equals(last)) {
tokens.push("");
}
}
else if (PARENT_DIR_OP.equals(token)) {
if (tokens.empty()) {
//-- this should be an error
throw new MalformedURLException("invalid absolute URL: " + absoluteURL);
}
tokens.pop();
}
else {
if (!CURRENT_DIR_OP.equals(token)) {
tokens.push(token);
}
}
last = token;
}
//-- rebuild URL
StringBuffer buffer = new StringBuffer(absoluteURL.length());
for (int i = 0; i < tokens.size(); i++) {
if (i > 0) buffer.append(HREF_PATH_SEP);
buffer.append(tokens.elementAt(i).toString());
}
return buffer.toString();
} //-- normalize
/**
*
**/
public static String resolveAsString(String href, String documentBase) {
try {
//-- try to create a new URL and see if MalformedURLExcetion is
//-- ever thrown
new URL(href);
return href;
}
catch(MalformedURLException muex) {}
//-- join document base + href
String absolute = null;
if ((documentBase != null) && (documentBase.length() > 0)) {
int idx = documentBase.lastIndexOf(HREF_PATH_SEP);
if (idx == (documentBase.length()-1))
absolute = documentBase+href;
else
absolute = documentBase+HREF_PATH_SEP+href;
}
else absolute = href;
try {
//-- try to create a new URL and see if MalformedURLExcetion is
//-- ever thrown
if (absolute.indexOf("./") >= 0) {
//-- normalize . or .. from URL
absolute = normalize(absolute);
}
new URL(absolute);
return absolute;
}
catch(MalformedURLException muex) {
//-- check for unrecognized protocol
int idx = absolute.indexOf(':');
if (idx >= 0) {
String scheme = absolute.substring(0, idx);
//-- a bit of a hack, but good enough for now
String error = "unknown protocol: " + scheme;
if (error.equals(muex.getMessage())) {
return absolute;
}
}
}
// Try local files
String fileURL = absolute;
File iFile = new File(href);
boolean exists = iFile.exists();
fileURL = createFileURL(iFile.getAbsolutePath());
if (!iFile.isAbsolute()) {
iFile = new File(absolute);
if (iFile.exists() || (!exists)) {
fileURL = createFileURL(iFile.getAbsolutePath());
}
}
//-- one last sanity check
try {
//-- try to create a new URL and see if MalformedURLExcetion is
//-- ever thrown
new URL(fileURL);
return fileURL;
}
catch(MalformedURLException muex) {}
//-- At this point we we're unsucessful at trying to resolve
//-- the href + documentbase, this could be due to a custom
//-- protocol or typo in the URI, just return documentBase +
//-- href
return absolute;
} //-- resolveHref
/**
* Creates a File URL for the given file name
*
* @param filename the name of the file
* @return the String representation of the File URL
**/
private static String createFileURL(String filename) {
if (filename == null) return FILE_PROTOCOL_PREFIX;
int size = filename.length() + FILE_PROTOCOL_PREFIX.length();
StringBuffer sb = new StringBuffer(size);
sb.append(FILE_PROTOCOL_PREFIX);
char[] chars = filename.toCharArray();
for (int i = 0; i < chars.length; i++) {
char ch = chars[i];
switch (ch) {
case '\\':
sb.append(HREF_PATH_SEP);
break;
default:
sb.append(ch);
break;
}
}
return sb.toString();
} //-- createFileURL
} //-- URIUtils