public URL(String spec) throws MalformedURLException 
{
        this(null, spec);
}

Creates a URL object from the String representation.

This constructor is equivalent to a call to the two-argument constructor with a null first argument.

Parameters:

spec - the String to parse as a URL.

Throws:

MalformedURLException - if no protocol is specified, or an unknown protocol is found, or spec is null.

Also see:

java.net.URL#URL(java.net.URL, java.lang.String)
exception: MalformedURLException - if no protocol is specified, or an unknown protocol is found, or spec is null.

 public URL(URL context,
    String spec) throws MalformedURLException 
{
        this(context, spec, null);
}

Creates a URL by parsing the given spec within a specified context. The new URL is created from the given context URL and the spec argument as described in RFC2396 "Uniform Resource Identifiers : Generic * Syntax" :

         <scheme>://<authority><path>?<query>#<fragment>

The reference is parsed into the scheme, authority, path, query and fragment parts. If the path component is empty and the scheme, authority, and query components are undefined, then the new URL is a reference to the current document. Otherwise, the fragment and query parts present in the spec are used in the new URL.

If the scheme component is defined in the given spec and does not match the scheme of the context, then the new URL is created as an absolute URL based on the spec alone. Otherwise the scheme component is inherited from the context URL.

If the authority component is present in the spec then the spec is treated as absolute and the spec authority and path will replace the context authority and path. If the authority component is absent in the spec then the authority of the new URL will be inherited from the context.

If the spec's path component begins with a slash character "/" then the path is treated as absolute and the spec path replaces the context path.

Otherwise, the path is treated as a relative path and is appended to the context path, as described in RFC2396. Also, in this case, the path is canonicalized through the removal of directory changes made by occurences of ".." and ".".

For a more detailed description of URL parsing, refer to RFC2396.

Parameters:

context - the context in which to parse the specification.

spec - the String to parse as a URL.

Throws:

MalformedURLException - if no protocol is specified, or an unknown protocol is found, or spec is null.

Also see:

java.net.URL#URL(java.lang.String, java.lang.String, int, java.lang.String)
java.net.URLStreamHandler
java.net.URLStreamHandler#parseURL(java.net.URL, java.lang.String, int, int)
exception: MalformedURLException - if no protocol is specified, or an unknown protocol is found, or spec is null.

 public URL(String protocol,
    String host,
    String file) throws MalformedURLException 
{
        this(protocol, host, -1, file);
}

Creates a URL from the specified protocol name, host name, and file name. The default port for the specified protocol is used.

This method is equivalent to calling the four-argument constructor with the arguments being protocol, host, -1, and file. No validation of the inputs is performed by this constructor.

Parameters:

protocol - the name of the protocol to use.

host - the name of the host.

file - the file on the host.

Throws:

MalformedURLException - if an unknown protocol is specified.

Also see:

java.net.URL#URL(java.lang.String, java.lang.String, int, java.lang.String)
exception: MalformedURLException - if an unknown protocol is specified.

 public URL(URL context,
    String spec,
    URLStreamHandler handler) throws MalformedURLException 
{
        String original = spec;
        int i, limit, c;
        int start = 0;
        String newProtocol = null;
        boolean aRef=false;
        boolean isRelative = false;
        // Check for permission to specify a handler
        if (handler != null) {
            SecurityManager sm = System.getSecurityManager();
            if (sm != null) {
                checkSpecifyHandler(sm);
            }
        }
        try {
            limit = spec.length();
            while ((limit  > 0) && (spec.charAt(limit - 1) < = ' ')) {
                limit--;        //eliminate trailing whitespace
            }
            while ((start <  limit) && (spec.charAt(start) < = ' ')) {
                start++;        // eliminate leading whitespace
            }
            if (spec.regionMatches(true, start, "url:", 0, 4)) {
                start += 4;
            }
            if (start <  spec.length() && spec.charAt(start) == '#') {
                /* we're assuming this is a ref relative to the context URL.
                 * This means protocols cannot start w/ '#', but we must parse
                 * ref URL's like: "hello:there" w/ a ':' in them.
                 */
                aRef=true;
            }
            for (i = start ; !aRef && (i <  limit) &&
                     ((c = spec.charAt(i)) != '/') ; i++) {
                if (c == ':') {
                    String s = spec.substring(start, i).toLowerCase();
                    if (isValidProtocol(s)) {
                        newProtocol = s;
                        start = i + 1;
                    }
                    break;
                }
            }
            // Only use our context if the protocols match.
            protocol = newProtocol;
            if ((context != null) && ((newProtocol == null) ||
                            newProtocol.equalsIgnoreCase(context.protocol))) {
                // inherit the protocol handler from the context
                // if not specified to the constructor
                if (handler == null) {
                    handler = context.handler;
                }
                // If the context is a hierarchical URL scheme and the spec
                // contains a matching scheme then maintain backwards
                // compatibility and treat it as if the spec didn't contain
                // the scheme; see 5.2.3 of RFC2396
                if (context.path != null && context.path.startsWith("/"))
                    newProtocol = null;
                if (newProtocol == null) {
                    protocol = context.protocol;
                    authority = context.authority;
                    userInfo = context.userInfo;
                    host = context.host;
                    port = context.port;
                    file = context.file;
                    path = context.path;
                    isRelative = true;
                }
            }
            if (protocol == null) {
                throw new MalformedURLException("no protocol: "+original);
            }
            // Get the protocol handler if not specified or the protocol
            // of the context could not be used
            if (handler == null &&
                (handler = getURLStreamHandler(protocol)) == null) {
                throw new MalformedURLException("unknown protocol: "+protocol);
            }
            this.handler = handler;
            i = spec.indexOf('#', start);
            if (i  >= 0) {
                ref = spec.substring(i + 1, limit);
                limit = i;
            }
            /*
             * Handle special case inheritance of query and fragment
             * implied by RFC2396 section 5.2.2.
             */
            if (isRelative && start == limit) {
                query = context.query;
                if (ref == null) {
                    ref = context.ref;
                }
            }
            handler.parseURL(this, spec, start, limit);
        } catch(MalformedURLException e) {
            throw e;
        } catch(Exception e) {
            MalformedURLException exception = new MalformedURLException(e.getMessage());
            exception.initCause(e);
            throw exception;
        }
}

Creates a URL by parsing the given spec with the specified handler within a specified context. If the handler is null, the parsing occurs as with the two argument constructor.

Parameters:

context - the context in which to parse the specification.

spec - the String to parse as a URL.

handler - the stream handler for the URL.

Throws:

MalformedURLException - if no protocol is specified, or an unknown protocol is found, or spec is null.

SecurityException - if a security manager exists and its checkPermission method doesn't allow specifying a stream handler.

Also see:

java.net.URL#URL(java.lang.String, java.lang.String, int, java.lang.String)
java.net.URLStreamHandler
java.net.URLStreamHandler#parseURL(java.net.URL, java.lang.String, int, int)
exception: MalformedURLException - if no protocol is specified, or an unknown protocol is found, or spec is null.

exception: SecurityException - if a security manager exists and its checkPermission method doesn't allow specifying a stream handler.

 public URL(String protocol,
    String host,
    int port,
    String file) throws MalformedURLException 
{
        this(protocol, host, port, file, null);
}

Creates a URL object from the specified protocol, host, port number, and file.

host can be expressed as a host name or a literal IP address. If IPv6 literal address is used, it should be enclosed in square brackets ('[' and ']'), as specified by RFC 2732; However, the literal IPv6 address format defined in RFC 2373: IP Version 6 Addressing Architecture is also accepted.

Specifying a port number of -1 indicates that the URL should use the default port for the protocol.

If this is the first URL object being created with the specified protocol, a stream protocol handler object, an instance of class URLStreamHandler, is created for that protocol:

1. If the application has previously set up an instance of URLStreamHandlerFactory as the stream handler factory, then the createURLStreamHandler method of that instance is called with the protocol string as an argument to create the stream protocol handler.
2. If no URLStreamHandlerFactory has yet been set up, or if the factory's createURLStreamHandler method returns null, then the constructor finds the value of the system property:

           java.protocol.handler.pkgs
       

   If the value of that system property is not null, it is interpreted as a list of packages separated by a vertical slash character '|'. The constructor tries to load the class named:

           <package>.<protocol>.Handler
       

   where <package> is replaced by the name of the package and <protocol> is replaced by the name of the protocol. If this class does not exist, or if the class exists but it is not a subclass of URLStreamHandler, then the next package in the list is tried.
3. If the previous step fails to find a protocol handler, then the constructor tries to load from a system default package.

           <system default package>.<protocol>.Handler
       

   If this class does not exist, or if the class exists but it is not a subclass of URLStreamHandler, then a MalformedURLException is thrown.

Protocol handlers for the following protocols are guaranteed to exist on the search path :-

    http, https, ftp, file, and jar

Protocol handlers for additional protocols may also be available.

No validation of the inputs is performed by this constructor.

Parameters:

protocol - the name of the protocol to use.

host - the name of the host.

port - the port number on the host.

file - the file on the host

Throws:

MalformedURLException - if an unknown protocol is specified.

Also see:

java.lang.System#getProperty(java.lang.String)
java.net.URL#setURLStreamHandlerFactory( java.net.URLStreamHandlerFactory)
java.net.URLStreamHandler
java.net.URLStreamHandlerFactory#createURLStreamHandler( java.lang.String)
exception: MalformedURLException - if an unknown protocol is specified.

 public URL(String protocol,
    String host,
    int port,
    String file,
    URLStreamHandler handler) throws MalformedURLException 
{
        if (handler != null) {
            SecurityManager sm = System.getSecurityManager();
            if (sm != null) {
                // check for permission to specify a handler
                checkSpecifyHandler(sm);
            }
        }
        protocol = protocol.toLowerCase();
        this.protocol = protocol;
        if (host != null) {
            /**
             * if host is a literal IPv6 address,
             * we will make it conform to RFC 2732
             */
            if (host.indexOf(':')  >= 0 && !host.startsWith("[")) {
                host = "["+host+"]";
            }
            this.host = host;
            if (port <  -1) {
                throw new MalformedURLException("Invalid port number :" +
                                                    port);
            }
            this.port = port;
            authority = (port == -1) ? host : host + ":" + port;
        }
        Parts parts = new Parts(file);
        path = parts.getPath();
        query = parts.getQuery();
        if (query != null) {
            this.file = path + "?" + query;
        } else {
            this.file = path;
        }
        ref = parts.getRef();
        // Note: we don't do validation of the URL here. Too risky to change
        // right now, but worth considering for future reference. -br
        if (handler == null &&
            (handler = getURLStreamHandler(protocol)) == null) {
            throw new MalformedURLException("unknown protocol: " + protocol);
        }
        this.handler = handler;
}

Creates a URL object from the specified protocol, host, port number, file, and handler. Specifying a port number of -1 indicates that the URL should use the default port for the protocol. Specifying a handler of null indicates that the URL should use a default stream handler for the protocol, as outlined for: java.net.URL#URL(java.lang.String, java.lang.String, int, java.lang.String)

If the handler is not null and there is a security manager, the security manager's checkPermission method is called with a NetPermission("specifyStreamHandler") permission. This may result in a SecurityException. No validation of the inputs is performed by this constructor.

Parameters:

protocol - the name of the protocol to use.

host - the name of the host.

port - the port number on the host.

file - the file on the host

handler - the stream handler for the URL.

Throws:

MalformedURLException - if an unknown protocol is specified.

SecurityException - if a security manager exists and its checkPermission method doesn't allow specifying a stream handler explicitly.

Also see:

java.lang.System#getProperty(java.lang.String)
java.net.URL#setURLStreamHandlerFactory( java.net.URLStreamHandlerFactory)
java.net.URLStreamHandler
java.net.URLStreamHandlerFactory#createURLStreamHandler( java.lang.String)
SecurityManager#checkPermission
java.net.NetPermission
exception: MalformedURLException - if an unknown protocol is specified.

exception: SecurityException - if a security manager exists and its checkPermission method doesn't allow specifying a stream handler explicitly.

 public boolean equals(Object obj) 
{
        if (!(obj instanceof URL))
            return false;
        URL u2 = (URL)obj;
        return handler.equals(this, u2);
}

Compares this URL for equality with another object.

If the given object is not a URL then this method immediately returns false.

Two URL objects are equal if they have the same protocol, reference equivalent hosts, have the same port number on the host, and the same file and fragment of the file.

Two hosts are considered equivalent if both host names can be resolved into the same IP addresses; else if either host name can't be resolved, the host names must be equal without regard to case; or both host names equal to null.

Since hosts comparison requires name resolution, this operation is a blocking operation.

Note: The defined behavior for equals is known to be inconsistent with virtual hosting in HTTP.

 public String getAuthority() 
{
        return authority;
}

Gets the authority part of this URL.

 public final Object getContent() throws IOException 
{
        return openConnection().getContent();
}

Gets the contents of this URL. This method is a shorthand for:

    openConnection().getContent()

 public final Object getContent(Class[] classes) throws IOException 
{
        return openConnection().getContent(classes);
}

Gets the contents of this URL. This method is a shorthand for:

    openConnection().getContent(Class[])

 public int getDefaultPort() 
{
        return handler.getDefaultPort();
}

Gets the default port number of the protocol associated with this URL. If the URL scheme or the URLStreamHandler for the URL do not define a default port number, then -1 is returned.

 public String getFile() 
{
        return file;
}

Gets the file name of this URL. The returned file portion will be the same as getPath(), plus the concatenation of the value of getQuery(), if any. If there is no query portion, this method and getPath() will return identical results.

 public String getHost() 
{
        return host;
}

Gets the host name of this URL, if applicable. The format of the host conforms to RFC 2732, i.e. for a literal IPv6 address, this method will return the IPv6 address enclosed in square brackets ('[' and ']').

 public String getPath() 
{
        return path;
}

Gets the path part of this URL.

 public int getPort() 
{
        return port;
}

Gets the port number of this URL.

 public String getProtocol() 
{
        return protocol;
}

Gets the protocol name of this URL.

 public String getQuery() 
{
        return query;
}

Gets the query part of this URL.

 public String getRef() 
{
        return ref;
}

Gets the anchor (also known as the "reference") of this URL.

 static URLStreamHandler getURLStreamHandler(String protocol) 
{
        URLStreamHandler handler = (URLStreamHandler)handlers.get(protocol);
        if (handler == null) {
            boolean checkedWithFactory = false;
            // Use the factory (if any)
            if (factory != null) {
                handler = factory.createURLStreamHandler(protocol);
                checkedWithFactory = true;
            }
            // Try java protocol handler
            if (handler == null) {
                String packagePrefixList = null;
                packagePrefixList
                    = java.security.AccessController.doPrivileged(
                    new sun.security.action.GetPropertyAction(
                        protocolPathProp,""));
                if (packagePrefixList != "") {
                    packagePrefixList += "|";
                }
                // REMIND: decide whether to allow the "null" class prefix
                // or not.
                packagePrefixList += "sun.net.www.protocol";
                StringTokenizer packagePrefixIter =
                    new StringTokenizer(packagePrefixList, "|");
                while (handler == null &&
                       packagePrefixIter.hasMoreTokens()) {
                    String packagePrefix =
                      packagePrefixIter.nextToken().trim();
                    try {
                        String clsName = packagePrefix + "." + protocol +
                          ".Handler";
                        Class cls = null;
                        try {
                            cls = Class.forName(clsName);
                        } catch (ClassNotFoundException e) {
                            ClassLoader cl = ClassLoader.getSystemClassLoader();
                            if (cl != null) {
                                cls = cl.loadClass(clsName);
                            }
                        }
                        if (cls != null) {
                            handler  =
                              (URLStreamHandler)cls.newInstance();
                        }
                    } catch (Exception e) {
                        // any number of exceptions can get thrown here
                    }
                }
            }
            synchronized (streamHandlerLock) {
                URLStreamHandler handler2 = null;
                // Check again with hashtable just in case another
                // thread created a handler since we last checked
                handler2 = (URLStreamHandler)handlers.get(protocol);
                if (handler2 != null) {
                    return handler2;
                }
                // Check with factory if another thread set a
                // factory since our last check
                if (!checkedWithFactory && factory != null) {
                    handler2 = factory.createURLStreamHandler(protocol);
                }
                if (handler2 != null) {
                    // The handler from the factory must be given more
                    // importance. Discard the default handler that
                    // this thread created.
                    handler = handler2;
                }
                // Insert this handler into the hashtable
                if (handler != null) {
                    handlers.put(protocol, handler);
                }
            }
        }
        return handler;
}

Returns the Stream Handler.

 public String getUserInfo() 
{
        return userInfo;
}

Gets the userInfo part of this URL.

 public synchronized int hashCode() 
{
        if (hashCode != -1)
            return hashCode;
        hashCode = handler.hashCode(this);
        return hashCode;
}

Creates an integer suitable for hash table indexing.

The hash code is based upon all the URL components relevant for URL comparison. As such, this operation is a blocking operation.

 public URLConnection openConnection() throws IOException 
{
        return handler.openConnection(this);
}

Returns a URLConnection instance that represents a connection to the remote object referred to by the {@code URL}.

A new instance of {@linkplain java.net.URLConnection URLConnection} is created every time when invoking the {@linkplain java.net.URLStreamHandler#openConnection(URL) URLStreamHandler.openConnection(URL)} method of the protocol handler for this URL.

It should be noted that a URLConnection instance does not establish the actual network connection on creation. This will happen only when calling {@linkplain java.net.URLConnection#connect() URLConnection.connect()}.

If for the URL'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.

 public URLConnection openConnection(Proxy proxy) throws IOException 
{
        if (proxy == null) {
            throw new IllegalArgumentException("proxy can not be null");
        }
        // Create a copy of Proxy as a security measure
        Proxy p = proxy == Proxy.NO_PROXY ? Proxy.NO_PROXY : sun.net.ApplicationProxy.create(proxy);
        SecurityManager sm = System.getSecurityManager();
        if (p.type() != Proxy.Type.DIRECT && sm != null) {
            InetSocketAddress epoint = (InetSocketAddress) p.address();
            if (epoint.isUnresolved())
                sm.checkConnect(epoint.getHostName(), epoint.getPort());
            else
                sm.checkConnect(epoint.getAddress().getHostAddress(),
                                epoint.getPort());
        }
        return handler.openConnection(this, p);
}

Same as #openConnection() , except that the connection will be made through the specified proxy; Protocol handlers that do not support proxing will ignore the proxy parameter and make a normal connection. Invoking this method preempts the system's default ProxySelector settings.

 public final InputStream openStream() throws IOException 
{
        return openConnection().getInputStream();
}

Opens a connection to this URL and returns an InputStream for reading from that connection. This method is a shorthand for:

    openConnection().getInputStream()

 public boolean sameFile(URL other) 
{
        return handler.sameFile(this, other);
}

Compares two URLs, excluding the fragment component.

Returns true if this URL and the other argument are equal without taking the fragment component into consideration.

 protected  void set(String protocol,
    String host,
    int port,
    String file,
    String ref) 
{
        synchronized (this) {
            this.protocol = protocol;
            this.host = host;
            authority = port == -1 ? host : host + ":" + port;
            this.port = port;
            this.file = file;
            this.ref = ref;
            /* This is very important. We must recompute this after the
             * URL has been changed. */
            hashCode = -1;
            hostAddress = null;
            int q = file.lastIndexOf('?');
            if (q != -1) {
                query = file.substring(q+1);
                path = file.substring(0, q);
            } else
                path = file;
        }
}

Sets the fields of the URL. This is not a public method so that only URLStreamHandlers can modify URL fields. URLs are otherwise constant.

 protected  void set(String protocol,
    String host,
    int port,
    String authority,
    String userInfo,
    String path,
    String query,
    String ref) 
{
        synchronized (this) {
            this.protocol = protocol;
            this.host = host;
            this.port = port;
            this.file = query == null ? path : path + "?" + query;
            this.userInfo = userInfo;
            this.path = path;
            this.ref = ref;
            /* This is very important. We must recompute this after the
             * URL has been changed. */
            hashCode = -1;
            hostAddress = null;
            this.query = query;
            this.authority = authority;
        }
}

Sets the specified 8 fields of the URL. This is not a public method so that only URLStreamHandlers can modify URL fields. URLs are otherwise constant.

 public static  void setURLStreamHandlerFactory(URLStreamHandlerFactory fac) 
{
        synchronized (streamHandlerLock) {
            if (factory != null) {
                throw new Error("factory already defined");
            }
            SecurityManager security = System.getSecurityManager();
            if (security != null) {
                security.checkSetFactory();
            }
            handlers.clear();
            factory = fac;
        }
}

Sets an application's URLStreamHandlerFactory. This method can be called at most once in a given Java Virtual Machine.

The URLStreamHandlerFactory instance is used to construct a stream protocol handler from a protocol name.

If there is a security manager, this method first calls the security manager's checkSetFactory method to ensure the operation is allowed. This could result in a SecurityException.

 public String toExternalForm() 
{
        return handler.toExternalForm(this);
}

Constructs a string representation of this URL. The string is created by calling the toExternalForm method of the stream protocol handler for this object.

 public String toString() 
{
        return toExternalForm();
}

Constructs a string representation of this URL. The string is created by calling the toExternalForm method of the stream protocol handler for this object.

 public URI toURI() throws URISyntaxException 
{
        return new URI (toString());
}

Returns a java.net.URI equivalent to this URL. This method functions in the same way as new URI (this.toString()).

Note, any URL instance that complies with RFC 2396 can be converted to a URI. However, some URLs that are not strictly in compliance can not be converted to a URI.