File	Doc	Category	Size	Date	Package
URLStreamHandler.java	API Doc	Java SE 6 API	19951	Tue Jun 10 00:25:42 BST 2008	java.net

URLStreamHandler

• java.lang.Object

Fields Summary

Constructors Summary

Methods Summary
protected boolean	equals(java.net.URL u1, java.net.URL u2) Provides the default equals calculation. May be overidden by handlers for other protocols that have different requirements for equals(). This method requires that none of its arguments is null. This is guaranteed by the fact that it is only called by java.net.URL class. param u1 a URL object param u2 a URL object return true if the two urls are considered equal, ie. they refer to the same fragment in the same file. since 1.3 String ref1 = u1.getRef(); String ref2 = u2.getRef(); return (ref1 == ref2 || (ref1 != null && ref1.equals(ref2))) && sameFile(u1, u2);
protected int	getDefaultPort() Returns the default port for a URL parsed by this handler. This method is meant to be overidden by handlers with default port numbers. return the default port for a URL parsed by this handler. since 1.3 return -1;
protected synchronized java.net.InetAddress	getHostAddress(java.net.URL u) Get the IP address of our host. An empty host field or a DNS failure will result in a null return. param u a URL object return an InetAddress representing the host IP address. since 1.3 if (u.hostAddress != null) return u.hostAddress; String host = u.getHost(); if (host == null || host.equals("")) { return null; } else { try { u.hostAddress = InetAddress.getByName(host); } catch (UnknownHostException ex) { return null; } catch (SecurityException se) { return null; } } return u.hostAddress;
protected int	hashCode(java.net.URL u) Provides the default hash calculation. May be overidden by handlers for other protocols that have different requirements for hashCode calculation. param u a URL object return an int suitable for hash table indexing since 1.3 int h = 0; // Generate the protocol part. String protocol = u.getProtocol(); if (protocol != null) h += protocol.hashCode(); // Generate the host part. InetAddress addr = getHostAddress(u); if (addr != null) { h += addr.hashCode(); } else { String host = u.getHost(); if (host != null) h += host.toLowerCase().hashCode(); } // Generate the file part. String file = u.getFile(); if (file != null) h += file.hashCode(); // Generate the port part. if (u.getPort() == -1) h += getDefaultPort(); else h += u.getPort(); // Generate the ref part. String ref = u.getRef(); if (ref != null) h += ref.hashCode(); return h;
protected boolean	hostsEqual(java.net.URL u1, java.net.URL u2) Compares the host components of two URLs. param u1 the URL of the first host to compare param u2 the URL of the second host to compare return true if and only if they are equal, false otherwise. since 1.3 InetAddress a1 = getHostAddress(u1); InetAddress a2 = getHostAddress(u2); // if we have internet address for both, compare them if (a1 != null && a2 != null) { return a1.equals(a2); // else, if both have host names, compare them } else if (u1.getHost() != null && u2.getHost() != null) return u1.getHost().equalsIgnoreCase(u2.getHost()); else return u1.getHost() == null && u2.getHost() == null;
protected abstract java.net.URLConnection	openConnection(java.net.URL u) Opens a connection to the object referenced by the URL argument. This method should be overridden by a subclass. If for the handler's protocol (such as HTTP or JAR), there exists a public, specialized URLConnection subclass belonging to one of the following packages or one of their subpackages: java.lang, java.io, java.util, java.net, the connection returned will be of that subclass. For example, for HTTP an HttpURLConnection will be returned, and for JAR a JarURLConnection will be returned. param u the URL that this connects to. return a URLConnection object for the URL. exception IOException if an I/O error occurs while opening the connection.
protected java.net.URLConnection	openConnection(java.net.URL u, java.net.Proxy p) Same as openConnection(URL), except that the connection will be made through the specified proxy; Protocol handlers that do not support proxying will ignore the proxy parameter and make a normal connection. Calling this method preempts the system's default ProxySelector settings. param u the URL that this connects to. param p the proxy through which the connection will be made. If direct connection is desired, Proxy.NO_PROXY should be specified. return a URLConnection object for the URL. exception IOException if an I/O error occurs while opening the connection. exception IllegalArgumentException if either u or p is null, or p has the wrong type. exception UnsupportedOperationException if the subclass that implements the protocol doesn't support this method. since 1.5 throw new UnsupportedOperationException("Method not implemented.");
protected void	parseURL(java.net.URL u, java.lang.String spec, int start, int limit) Parses the string representation of a URL into a URL object. If there is any inherited context, then it has already been copied into the URL argument. The parseURL method of URLStreamHandler parses the string representation as if it were an http specification. Most URL protocol families have a similar parsing. A stream protocol handler for a protocol that has a different syntax must override this routine. param u the URL to receive the result of parsing the spec. param spec the String representing the URL that must be parsed. param start the character index at which to begin parsing. This is just past the ':' (if there is one) that specifies the determination of the protocol name. param limit the character position to stop parsing at. This is the end of the string or the position of the "#" character, if present. All information after the sharp sign indicates an anchor. // These fields may receive context content if this was relative URL String protocol = u.getProtocol(); String authority = u.getAuthority(); String userInfo = u.getUserInfo(); String host = u.getHost(); int port = u.getPort(); String path = u.getPath(); String query = u.getQuery(); // This field has already been parsed String ref = u.getRef(); boolean isRelPath = false; boolean queryOnly = false; // FIX: should not assume query if opaque // Strip off the query part if (start < limit) { int queryStart = spec.indexOf('?"); queryOnly = queryStart == start; if ((queryStart != -1) && (queryStart < limit)) { query = spec.substring(queryStart+1, limit); if (limit > queryStart) limit = queryStart; spec = spec.substring(0, queryStart); } } int i = 0; // Parse the authority part if any boolean isUNCName = (start <= limit - 4) && (spec.charAt(start) == '/") && (spec.charAt(start + 1) == '/") && (spec.charAt(start + 2) == '/") && (spec.charAt(start + 3) == '/"); if (!isUNCName && (start <= limit - 2) && (spec.charAt(start) == '/") && (spec.charAt(start + 1) == '/")) { start += 2; i = spec.indexOf('/", start); if (i < 0) { i = spec.indexOf('?", start); if (i < 0) i = limit; } host = authority = spec.substring(start, i); int ind = authority.indexOf('@"); if (ind != -1) { userInfo = authority.substring(0, ind); host = authority.substring(ind+1); } else { userInfo = null; } if (host != null) { // If the host is surrounded by [ and ] then its an IPv6 // literal address as specified in RFC2732 if (host.length()>0 && (host.charAt(0) == '[")) { if ((ind = host.indexOf(']")) > 2) { String nhost = host ; host = nhost.substring(0,ind+1); if (!IPAddressUtil. isIPv6LiteralAddress(host.substring(1, ind))) { throw new IllegalArgumentException( "Invalid host: "+ host); } port = -1 ; if (nhost.length() > ind+1) { if (nhost.charAt(ind+1) == ':") { ++ind ; // port can be null according to RFC2396 if (nhost.length() > (ind + 1)) { port = Integer.parseInt(nhost.substring(ind+1)); } } else { throw new IllegalArgumentException( "Invalid authority field: " + authority); } } } else { throw new IllegalArgumentException( "Invalid authority field: " + authority); } } else { ind = host.indexOf(':"); port = -1; if (ind >= 0) { // port can be null according to RFC2396 if (host.length() > (ind + 1)) { port = Integer.parseInt(host.substring(ind + 1)); } host = host.substring(0, ind); } } } else { host = ""; } if (port < -1) throw new IllegalArgumentException("Invalid port number :" + port); start = i; // If the authority is defined then the path is defined by the // spec only; See RFC 2396 Section 5.2.4. if (authority != null && authority.length() > 0) path = ""; } if (host == null) { host = ""; } // Parse the file path if any if (start < limit) { if (spec.charAt(start) == '/") { path = spec.substring(start, limit); } else if (path != null && path.length() > 0) { isRelPath = true; int ind = path.lastIndexOf('/"); String seperator = ""; if (ind == -1 && authority != null) seperator = "/"; path = path.substring(0, ind + 1) + seperator + spec.substring(start, limit); } else { String seperator = (authority != null) ? "/" : ""; path = seperator + spec.substring(start, limit); } } else if (queryOnly && path != null) { int ind = path.lastIndexOf('/"); if (ind < 0) ind = 0; path = path.substring(0, ind) + "/"; } if (path == null) path = ""; if (isRelPath) { // Remove embedded /./ while ((i = path.indexOf("/./")) >= 0) { path = path.substring(0, i) + path.substring(i + 2); } // Remove embedded /../ if possible i = 0; while ((i = path.indexOf("/../", i)) >= 0) { /* * A "/../" will cancel the previous segment and itself, * unless that segment is a "/../" itself * i.e. "/a/b/../c" becomes "/a/c" * but "/../../a" should stay unchanged */ if (i > 0 && (limit = path.lastIndexOf('/", i - 1)) >= 0 && (path.indexOf("/../", limit) != 0)) { path = path.substring(0, limit) + path.substring(i + 3); i = 0; } else { i = i + 3; } } // Remove trailing .. if possible while (path.endsWith("/..")) { i = path.indexOf("/.."); if ((limit = path.lastIndexOf('/", i - 1)) >= 0) { path = path.substring(0, limit+1); } else { break; } } // Remove starting . if (path.startsWith("./") && path.length() > 2) path = path.substring(2); // Remove trailing . if (path.endsWith("/.")) path = path.substring(0, path.length() -1); } setURL(u, protocol, host, port, authority, userInfo, path, query, ref);
protected boolean	sameFile(java.net.URL u1, java.net.URL u2) Compare two urls to see whether they refer to the same file, i.e., having the same protocol, host, port, and path. This method requires that none of its arguments is null. This is guaranteed by the fact that it is only called indirectly by java.net.URL class. param u1 a URL object param u2 a URL object return true if u1 and u2 refer to the same file since 1.3 // Compare the protocols. if (!((u1.getProtocol() == u2.getProtocol()) || (u1.getProtocol() != null && u1.getProtocol().equalsIgnoreCase(u2.getProtocol())))) return false; // Compare the files. if (!(u1.getFile() == u2.getFile() || (u1.getFile() != null && u1.getFile().equals(u2.getFile())))) return false; // Compare the ports. int port1, port2; port1 = (u1.getPort() != -1) ? u1.getPort() : u1.handler.getDefaultPort(); port2 = (u2.getPort() != -1) ? u2.getPort() : u2.handler.getDefaultPort(); if (port1 != port2) return false; // Compare the hosts. if (!hostsEqual(u1, u2)) return false; return true;
protected void	setURL(java.net.URL u, java.lang.String protocol, java.lang.String host, int port, java.lang.String authority, java.lang.String userInfo, java.lang.String path, java.lang.String query, java.lang.String ref) Sets the fields of the URL argument to the indicated values. Only classes derived from URLStreamHandler are supposed to be able to call the set method on a URL. param u the URL to modify. param protocol the protocol name. param host the remote host value for the URL. param port the port on the remote machine. param authority the authority part for the URL. param userInfo the userInfo part of the URL. param path the path component of the URL. param query the query part for the URL. param ref the reference. exception SecurityException if the protocol handler of the URL is different from this one see java.net.URL#set(java.lang.String, java.lang.String, int, java.lang.String, java.lang.String) since 1.3 if (this != u.handler) { throw new SecurityException("handler for url different from " + "this handler"); } // ensure that no one can reset the protocol on a given URL. u.set(u.getProtocol(), host, port, authority, userInfo, path, query, ref);
protected void	setURL(java.net.URL u, java.lang.String protocol, java.lang.String host, int port, java.lang.String file, java.lang.String ref) Sets the fields of the URL argument to the indicated values. Only classes derived from URLStreamHandler are supposed to be able to call the set method on a URL. param u the URL to modify. param protocol the protocol name. This value is ignored since 1.2. param host the remote host value for the URL. param port the port on the remote machine. param file the file. param ref the reference. exception SecurityException if the protocol handler of the URL is different from this one deprecated Use setURL(URL, String, String, int, String, String, String, String); /* * Only old URL handlers call this, so assume that the host * field might contain "user:passwd@host". Fix as necessary. */ String authority = null; String userInfo = null; if (host != null && host.length() != 0) { authority = (port == -1) ? host : host + ":" + port; int at = host.lastIndexOf('@"); if (at != -1) { userInfo = host.substring(0, at); host = host.substring(at+1); } } /* * Assume file might contain query part. Fix as necessary. */ String path = null; String query = null; if (file != null) { int q = file.lastIndexOf('?"); if (q != -1) { query = file.substring(q+1); path = file.substring(0, q); } else path = file; } setURL(u, protocol, host, port, authority, userInfo, path, query, ref);
protected java.lang.String	toExternalForm(java.net.URL u) Converts a URL of a specific protocol to a String. param u the URL. return a string representation of the URL argument. // pre-compute length of StringBuffer int len = u.getProtocol().length() + 1; if (u.getAuthority() != null && u.getAuthority().length() > 0) len += 2 + u.getAuthority().length(); if (u.getPath() != null) { len += u.getPath().length(); } if (u.getQuery() != null) { len += 1 + u.getQuery().length(); } if (u.getRef() != null) len += 1 + u.getRef().length(); StringBuffer result = new StringBuffer(len); result.append(u.getProtocol()); result.append(":"); if (u.getAuthority() != null && u.getAuthority().length() > 0) { result.append("//"); result.append(u.getAuthority()); } if (u.getPath() != null) { result.append(u.getPath()); } if (u.getQuery() != null) { result.append('?"); result.append(u.getQuery()); } if (u.getRef() != null) { result.append("#"); result.append(u.getRef()); } return result.toString();