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package com.sun.star.lib.util;
import java.io.File;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
/**
* Maps Java URL representations to File representations, on any Java version.
*
* @since UDK 3.2.8
*/
public final class UrlToFileMapper {
// java.net.URLEncoder.encode(String, String) and java.net.URI are only
// available since Java 1.4:
private static Method urlEncoderEncode;
private static Constructor uriConstructor;
private static Constructor fileConstructor;
static {
try {
urlEncoderEncode = URLEncoder.class.getMethod(
"encode", new Class[] { String.class, String.class });
Class uriClass = Class.forName("java.net.URI");
uriConstructor = uriClass.getConstructor(
new Class[] { String.class });
fileConstructor = File.class.getConstructor(
new Class[] { uriClass });
} catch (ClassNotFoundException e) {
} catch (NoSuchMethodException e) {
}
}
/**
* Maps Java URL representations to File representations.
*
* @param url some URL, possibly null.
* @return a corresponding File, or null on failure.
*/
public static File mapUrlToFile(URL url) {
if (url == null) {
return null;
} else if (fileConstructor == null) {
// If java.net.URI is not available, hope that the following works
// well: First, check that the given URL has a certain form.
// Second, use the URLDecoder to decode the URL path (taking care
// not to change any plus signs to spaces), hoping that the used
// default encoding is the proper one for file URLs. Third, create
// a File from the decoded path.
return url.getProtocol().equalsIgnoreCase("file")
&& url.getAuthority() == null && url.getQuery() == null
&& url.getRef() == null
? new File(URLDecoder.decode(
StringHelper.replace(url.getPath(), '+', "%2B")))
: null;
} else {
// If java.net.URI is avaliable, do
// URI uri = new URI(encodedUrl);
// try {
// return new File(uri);
// } catch (IllegalArgumentException e) {
// return null;
// }
// where encodedUrl is url.toString(), but since that may contain
// unsafe characters (e.g., space, " "), it is encoded, as otherwise
// the URI constructor might throw java.net.URISyntaxException (in
// Java 1.5, URL.toURI might be used instead).
String encodedUrl = encode(url.toString());
try {
Object uri = uriConstructor.newInstance(
new Object[] { encodedUrl });
try {
return (File) fileConstructor.newInstance(
new Object[] { uri });
} catch (InvocationTargetException e) {
if (e.getTargetException() instanceof
IllegalArgumentException) {
return null;
} else {
throw e;
}
}
} catch (InstantiationException e) {
throw new RuntimeException("This cannot happen: " + e);
} catch (IllegalAccessException e) {
throw new RuntimeException("This cannot happen: " + e);
} catch (InvocationTargetException e) {
if (e.getTargetException() instanceof Error) {
throw (Error) e.getTargetException();
} else if (e.getTargetException() instanceof RuntimeException) {
throw (RuntimeException) e.getTargetException();
} else {
throw new RuntimeException("This cannot happen: " + e);
}
}
}
}
private static String encode(String url) {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < url.length(); ++i) {
char c = url.charAt(i);
// The RFC 2732 characters: !$&'()*+,-./:;=?@[]_~ plus digits
// and letters; additionally, do not encode % again.
if (c >= 'a' && c <= 'z' || c >= '?' && c <= '['
|| c >= '$' && c <= ';' || c == '!' || c == '=' || c == ']'
|| c == '_' || c == '~')
{
buf.append(c);
} else if (c == ' ') {
buf.append("%20");
} else {
String enc;
try {
enc = (String) urlEncoderEncode.invoke(
null,
new Object[] {Character.toString(c), "UTF-8" });
} catch (IllegalAccessException e) {
throw new RuntimeException("This cannot happen: " + e);
} catch (InvocationTargetException e) {
throw new RuntimeException("This cannot happen: " + e);
}
buf.append(enc);
}
}
return buf.toString();
}
private UrlToFileMapper() {}
}