public class Handler extends URLStreamHandler
WrongMessageDigestException is thrown. HTTPMD URLs may be used to guarantee the integrity of a downloaded object's codebase if used when specifying the URLs for the JAR files containing the object's classes. Because HTTPMD URLs specify a message digest for a single item, they should not be used for directories of classes.
HTTPMD URLs have a syntax similar to that of HTTP URLs, but include a
message digest as the last parameter stored in the last segment of the
path. The parameter is introduced by the ';' character, and
includes the name of the message digest algorithm, a '=', the
message digest, and an optional comment introduced by the ','
character. In addition, a comment by itself may be specified in a relative
HTTPMD URL. Comments are ignored when using equals to compare
HTTPMD URLs. The comment specified in the context URL is ignored when
parsing a relative HTTPMD URL. Adding a comment to an HTTPMD URL is useful
in cases where the URL is required to have a particular suffix, for example
the ".jar" file extension. A comment-only relative HTTPMD URL is useful when
specifying the URL of the containing document from within the contents of
the document, where the message digest cannot be specified because it is not
yet known.
The message digest algorithm is case-insensitive, and may include ASCII letters and numbers, as well as the following characters:
- _ . ~ * ' ( ) : @ & + $ ,
The value specifies the name of the MessageDigest algorithm to
use. For the URL syntax to be valid, the value must be the name of a
MessageDigest algorithm as determined by calling
MessageDigest.getInstance(String).
The message digest is represented as a positive hexadecimal integer, using
digits, and the letters 'a' through 'f', in either
lowercase or uppercase.
The characters following the ',' comment character may include
ASCII letters and numbers, as well as the following characters:
- _ . ~ * ' ( ) : @ & = + $ ,
Here are some examples of HTTPMD URLs:
httpmd://www.sun.com/index.html;md5=7be207c7111e459eeea1c9b3d04f1667
index.html;sha=99f6837808c0a79398bf69d83cfb1b82d20cf0cf,Comment
,.jar
HttpmdUtil| Constructor and Description |
|---|
Handler()
Creates a URL stream handler for HTTPMD URLs.
|
| Modifier and Type | Method and Description |
|---|---|
protected int |
getDefaultPort()
Returns the default port for a URL parsed by this handler, which is
80. |
protected int |
hashCode(URL u)
Computes the hash code for the specified URL.
|
protected boolean |
hostsEqual(URL u1,
URL u2)
The default superclass implementation performs dns lookup to determine
if hosts are equal, this allows two URL's with different hashCode's
to be equal, breaking the hashCode equals contract.
|
protected URLConnection |
openConnection(URL u)
Creates a HTTP URL connection for an HTTPMD URL.
|
protected void |
parseURL(URL url,
String spec,
int start,
int limit)
Parses the string representation of an HTTPMD URL object.
|
protected boolean |
sameFile(URL u1,
URL u2)
Compares two HTTPMD URLs to see if they refer to the same file.
|
equals, getHostAddress, openConnection, setURL, setURL, toExternalFormprotected int getDefaultPort()
80.getDefaultPort in class URLStreamHandlerprotected URLConnection openConnection(URL u) throws IOException
openConnection in class URLStreamHandlerIOExceptionprotected void parseURL(URL url, String spec, int start, int limit)
parseURL in class URLStreamHandlerIllegalArgumentException - if the URL is malformedprotected boolean hostsEqual(URL u1, URL u2)
hostsEqual in class URLStreamHandlerprotected boolean sameFile(URL u1, URL u2)
hostsEqual to
compare the hosts, compares the ports, with -1 matching the
default HTTP port (80), and performs case-sensitive
comparison on the remaining portions.sameFile in class URLStreamHandlerprotected int hashCode(URL u)
hashCode in class URLStreamHandler