net.jini.url.httpmd

Class HttpmdUtil

java.lang.Object

net.jini.url.httpmd.HttpmdUtil

public class HttpmdUtil
extends Object

Provides utility methods for creating and using HTTPMD URLs.

Since:

2.0

Author:

Sun Microsystems, Inc.

Field Summary

Fields

Modifier and Type	Field and Description
private static Handler	handler A URL handler to use for HTTPMD URLs so we don't require the protocol handler to be installed.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	HttpmdUtil() Not instantiable.

Method Summary

Modifier and Type	Method and Description
(package private) static boolean	commentChar(char c) Returns true if the character is permitted in an HTTPMD comment.
private static String	computeDigest(InputStream in, String algorithm) Computes the message digest for an input stream.
static String	computeDigest(URL url, String algorithm) Computes the message digest of data specified by a URL.
static String	computeDigestCodebase(String sourceDirectory, String codebase) Computes the message digests for a codebase with HTTPMD URLs.
(package private) static String	digestString(byte[] digest) Converts a message digest to a String in hexadecimal format.
(package private) static byte[]	stringDigest(String s) Converts a String in hexadecimal format to a message digest.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

handler

private static final Handler handler

A URL handler to use for HTTPMD URLs so we don't require the protocol handler to be installed.

Constructor Detail

HttpmdUtil

private HttpmdUtil()

Not instantiable.

Method Detail

computeDigest

public static String computeDigest(URL url,
                                   String algorithm)
                            throws IOException,
                                   NoSuchAlgorithmException

Computes the message digest of data specified by a URL.

Parameters:

url - the URL of the data

algorithm - the message digest algorithm to use

Returns:

the message digest, as a String in hexadecimal format

Throws:

IOException - if an I/O exception occurs while reading data from the URL

NoSuchAlgorithmException - if no provider is found for the message digest algorithm

NullPointerException - if either argument is null

computeDigest

private static String computeDigest(InputStream in,
                                    String algorithm)
                             throws IOException,
                                    NoSuchAlgorithmException

Computes the message digest for an input stream.

Throws:

IOException

NoSuchAlgorithmException

computeDigestCodebase

public static String computeDigestCodebase(String sourceDirectory,
                                           String codebase)
                                    throws IOException,
                                           MalformedURLException,
                                           NullPointerException

Computes the message digests for a codebase with HTTPMD URLs.

Do not use a directory on a remote filesystem, or a directory URL, if the underlying network access protocol does not provide adequate data integrity or authentication of the remote host.

Parameters:

sourceDirectory - the filename or URL of the directory containing the source files corresponding to the URLs in codebase

codebase - a space-separated list of HTTPMD URLs. The digest values specified in the URLs will be ignored. The path portion of the URLs, without the message digest parameters, will be used to specify the source files, relative to sourceDirectory, to use for computing message digests.

Returns:

the codebase updated to include computed digests

Throws:

IllegalArgumentException - if any of the URLs in codebase fail to specify the HTTPMD protocol

IOException - if an I/O exception occurs while reading data from the source files

MalformedURLException - if any of the URLs in codebase have incorrect syntax

NullPointerException - if either argument is null

digestString

static String digestString(byte[] digest)

Converts a message digest to a String in hexadecimal format.

stringDigest

static byte[] stringDigest(String s)
                    throws NumberFormatException

Converts a String in hexadecimal format to a message digest.

Throws:

NumberFormatException

commentChar

static boolean commentChar(char c)

Returns true if the character is permitted in an HTTPMD comment. Legal comment characters are ASCII letters and numbers, plus '-', '_', '.', '~', '*', ''', '(', ')', ':', '@', '&', '=', '+', '$', and ','.