- java.lang.Object
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- java.net.URLStreamHandler
 
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 public abstract class URLStreamHandler extends Object The abstract classURLStreamHandleris the common superclass for all stream protocol handlers. A stream protocol handler knows how to make a connection for a particular protocol type, such ashttporhttps.In most cases, an instance of a URLStreamHandlersubclass is not created directly by an application. Rather, the first time a protocol name is encountered when constructing aURL, the appropriate stream protocol handler is automatically loaded.- Since:
- 1.0
- See Also:
- URL(java.lang.String, java.lang.String, int, java.lang.String)
 
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Constructor SummaryConstructors Constructor Description URLStreamHandler()
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Method SummaryAll Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods Modifier and Type Method Description protected booleanequals(URL u1, URL u2)Provides the default equals calculation.protected intgetDefaultPort()Returns the default port for a URL parsed by this handler.protected InetAddressgetHostAddress(URL u)Get the IP address of our host.protected inthashCode(URL u)Provides the default hash calculation.protected booleanhostsEqual(URL u1, URL u2)Compares the host components of two URLs.protected abstract URLConnectionopenConnection(URL u)Opens a connection to the object referenced by theURLargument.protected URLConnectionopenConnection(URL u, 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.protected voidparseURL(URL u, String spec, int start, int limit)Parses the string representation of aURLinto aURLobject.protected booleansameFile(URL u1, URL u2)Compare two urls to see whether they refer to the same file, i.e., having the same protocol, host, port, and path.protected voidsetURL(URL u, String protocol, String host, int port, String file, String ref)Deprecated.Use setURL(URL, String, String, int, String, String, String, String);protected voidsetURL(URL u, String protocol, String host, int port, String authority, String userInfo, String path, String query, String ref)Sets the fields of theURLargument to the indicated values.protected StringtoExternalForm(URL u)Converts aURLof a specific protocol to aString.
 
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Method Detail- 
openConnectionprotected abstract URLConnection openConnection(URL u) throws IOException Opens a connection to the object referenced by theURLargument. 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. - Parameters:
- u- the URL that this connects to.
- Returns:
- a URLConnectionobject for theURL.
- Throws:
- IOException- if an I/O error occurs while opening the connection.
 
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openConnectionprotected URLConnection openConnection(URL u, Proxy p) throws IOException 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 defaultProxySelectorsettings.- Parameters:
- u- the URL that this connects to.
- p- the proxy through which the connection will be made. If direct connection is desired, Proxy.NO_PROXY should be specified.
- Returns:
- a URLConnectionobject for theURL.
- Throws:
- IOException- if an I/O error occurs while opening the connection.
- IllegalArgumentException- if either u or p is null, or p has the wrong type.
- UnsupportedOperationException- if the subclass that implements the protocol doesn't support this method.
- Since:
- 1.5
 
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parseURLprotected void parseURL(URL u, String spec, int start, int limit) Parses the string representation of aURLinto aURLobject.If there is any inherited context, then it has already been copied into the URLargument.The parseURLmethod ofURLStreamHandlerparses the string representation as if it were anhttpspecification. Most URL protocol families have a similar parsing. A stream protocol handler for a protocol that has a different syntax must override this routine.- Parameters:
- u- the- URLto receive the result of parsing the spec.
- spec- the- Stringrepresenting the URL that must be parsed.
- 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.
- 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.
 
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getDefaultPortprotected 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.- Returns:
- the default port for a URLparsed by this handler.
- Since:
- 1.3
 
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equalsprotected boolean equals(URL u1, 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.- Parameters:
- u1- a URL object
- u2- a URL object
- Returns:
- trueif the two urls are considered equal, ie. they refer to the same fragment in the same file.
- Since:
- 1.3
 
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hashCodeprotected int hashCode(URL u) Provides the default hash calculation. May be overidden by handlers for other protocols that have different requirements for hashCode calculation.- Parameters:
- u- a URL object
- Returns:
- an intsuitable for hash table indexing
- Since:
- 1.3
 
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sameFileprotected boolean sameFile(URL u1, 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.- Parameters:
- u1- a URL object
- u2- a URL object
- Returns:
- true if u1 and u2 refer to the same file
- Since:
- 1.3
 
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getHostAddressprotected InetAddress getHostAddress(URL u) Get the IP address of our host. An empty host field or a DNS failure will result in a null return.- Parameters:
- u- a URL object
- Returns:
- an InetAddressrepresenting the host IP address.
- Since:
- 1.3
 
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hostsEqualprotected boolean hostsEqual(URL u1, URL u2) Compares the host components of two URLs.- Parameters:
- u1- the URL of the first host to compare
- u2- the URL of the second host to compare
- Returns:
- trueif and only if they are equal,- falseotherwise.
- Since:
- 1.3
 
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toExternalFormprotected String toExternalForm(URL u) Converts aURLof a specific protocol to aString.- Parameters:
- u- the URL.
- Returns:
- a string representation of the URLargument.
 
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setURLprotected void setURL(URL u, String protocol, String host, int port, String authority, String userInfo, String path, String query, String ref) Sets the fields of theURLargument to the indicated values. Only classes derived from URLStreamHandler are able to use this method to set the values of the URL fields.- Parameters:
- u- the URL to modify.
- protocol- the protocol name.
- host- the remote host value for the URL.
- port- the port on the remote machine.
- authority- the authority part for the URL.
- userInfo- the userInfo part of the URL.
- path- the path component of the URL.
- query- the query part for the URL.
- ref- the reference.
- Throws:
- SecurityException- if the protocol handler of the URL is different from this one
- Since:
- 1.3
 
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setURL@Deprecated protected void setURL(URL u, String protocol, String host, int port, String file, String ref) Deprecated.Use setURL(URL, String, String, int, String, String, String, String);Sets the fields of theURLargument to the indicated values. Only classes derived from URLStreamHandler are able to use this method to set the values of the URL fields.- Parameters:
- u- the URL to modify.
- protocol- the protocol name. This value is ignored since 1.2.
- host- the remote host value for the URL.
- port- the port on the remote machine.
- file- the file.
- ref- the reference.
- Throws:
- SecurityException- if the protocol handler of the URL is different from this one
 
 
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