/*
* @(#)URLConnection.java 1.54 98/10/02
*
* Copyright 1995-1998 by Sun Microsystems, Inc.,
* 901 San Antonio Road, Palo Alto, California, 94303, U.S.A.
* All rights reserved.
*
* This software is the confidential and proprietary information
* of Sun Microsystems, Inc. ("Confidential Information"). You
* shall not disclose such Confidential Information and shall use
* it only in accordance with the terms of the license agreement
* you entered into with Sun.
*/
package java.net;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Hashtable;
import java.util.Date;
import java.util.StringTokenizer;
import java.security.Permission;
import java.security.AccessController;
/**
* The abstract class <code>URLConnection</code> is the superclass
* of all classes that represent a communications link between the
* application and a URL. Instances of this class can be used both to
* read from and to write to the resource referenced by the URL. In
* general, creating a connection to a URL is a multistep process:
* <p>
* <center><table border=2>
* <tr><th><code>openConnection()</code></th>
* <th><code>connect()</code></th></tr>
* <tr><td>Manipulate parameters that affect the connection to the remote
* resource.</td>
* <td>Interact with the resource; query header fields and
* contents.</td></tr>
* </table>
* ---------------------------->
* <br>time</center>
*
* <ol>
* <li>The connection object is created by invoking the
* <code>openConnection</code> method on a URL.
* <li>The setup parameters and general request properties are manipulated.
* <li>The actual connection to the remote object is made, using the
* <code>connect</code> method.
* <li>The remote object becomes available. The header fields and the contents
* of the remote object can be accessed.
* </ol>
* <p>
* The setup parameters are modified using the following methods:
* <ul>
* <li><code>setAllowUserInteraction</code>
* <li><code>setDoInput</code>
* <li><code>setDoOutput</code>
* <li><code>setIfModifiedSince</code>
* <li><code>setUseCaches</code>
* </ul>
* <p>
* and the general request properties are modified using the method:
* <ul>
* <li><code>setRequestProperty</code>
* </ul>
* <p>
* Default values for the <code>AllowUserInteraction</code> and
* <code>UseCaches</code> parameters can be set using the methods
* <code>setDefaultAllowUserInteraction</code> and
* <code>setDefaultUseCaches</code>. Default values for general
* request properties can be set using the
* <code>setDefaultRequestProperty</code> method.
* <p>
* Each of the above <code>set</code> methods has a corresponding
* <code>get</code> method to retrieve the value of the parameter or
* general request property. The specific parameters and general
* request properties that are applicable are protocol specific.
* <p>
* The following methods are used to access the header fields and
* the contents after the connection is made to the remote object:
* <ul>
* <li><code>getContent</code>
* <li><code>getHeaderField</code>
* <li><code>getInputStream</code>
* <li><code>getOutputStream</code>
* </ul>
* <p>
* Certain header fields are accessed frequently. The methods:
* <ul>
* <li><code>getContentEncoding</code>
* <li><code>getContentLength</code>
* <li><code>getContentType</code>
* <li><code>getDate</code>
* <li><code>getExpiration</code>
* <li><code>getLastModifed</code>
* </ul>
* <p>
* provide convenient access to these fields. The
* <code>getContentType</code> method is used by the
* <code>getContent</code> method to determine the type of the remote
* object; subclasses may find it convenient to override the
* <code>getContentType</code> method.
* <p>
* In the common case, all of the pre-connection parameters and
* general request properties can be ignored: the pre-connection
* parameters and request properties default to sensible values. For
* most clients of this interface, there are only two interesting
* methods: <code>getInputStream</code> and <code>getObject</code>,
* which are mirrored in the <code>URL</code> class by convenience methods.
* <p>
* More information on the request properties and header fields of
* an <code>http</code> connection can be found at:
* <blockquote><pre>
* http://www.w3.org/hypertext/WWW/Protocols/HTTP1.0/draft-ietf-http-spec.html
* </pre></blockquote>
*
* Note about <code>fileNameMap</code>: In versions prior to JDK 1.1.6,
* field <code>fileNameMap</code> of <code>URLConnection</code> was public.
* In JDK 1.1.6 and later, <code>fileNameMap</code> is private; accessor
* and mutator methods {@link #getFileNameMap() getFileNameMap} and
* {@link #setFileNameMap(java.net.FileNameMap) setFileNameMap} are added
* to access it. This change is also described on the <a href=
* "http://java.sun.com/products/jdk/1.2/compatibility.html#incompatibilities1.1">
* JDK Compatibility</a> page.
*
* @author James Gosling
* @version 1.54, 10/02/98
* @see java.net.URL#openConnection()
* @see java.net.URLConnection#connect()
* @see java.net.URLConnection#getContent()
* @see java.net.URLConnection#getContentEncoding()
* @see java.net.URLConnection#getContentLength()
* @see java.net.URLConnection#getContentType()
* @see java.net.URLConnection#getDate()
* @see java.net.URLConnection#getExpiration()
* @see java.net.URLConnection#getHeaderField(int)
* @see java.net.URLConnection#getHeaderField(java.lang.String)
* @see java.net.URLConnection#getInputStream()
* @see java.net.URLConnection#getLastModified()
* @see java.net.URLConnection#getOutputStream()
* @see java.net.URLConnection#setAllowUserInteraction(boolean)
* @see java.net.URLConnection#setDefaultRequestProperty(java.lang.String, java.lang.String)
* @see java.net.URLConnection#setDefaultUseCaches(boolean)
* @see java.net.URLConnection#setDoInput(boolean)
* @see java.net.URLConnection#setDoOutput(boolean)
* @see java.net.URLConnection#setIfModifiedSince(long)
* @see java.net.URLConnection#setRequestProperty(java.lang.String, java.lang.String)
* @see java.net.URLConnection#setUseCaches(boolean)
* @since JDK1.0
*/
public abstract class URLConnection {
/**
* The URL represents the remote object on the World Wide Web to
* which this connection is opened.
* <p>
* The value of this field can be accessed by the
* <code>getURL</code> method.
* <p>
* The default value of this variable is the value of the URL
* argument in the <code>URLConnection</code> constructor.
*
* @see java.net.URLConnection#getURL()
* @see java.net.URLConnection#url
*/
protected URL url;
/**
* This variable is set by the <code>setDoInput</code> method. Its
* value is returned by the <code>getDoInput</code> method.
* <p>
* A URL connection can be used for input and/or output. Setting the
* <code>doInput</code> flag to <code>true</code> indicates that
* the application intends to read data from the URL connection.
* <p>
* The default value of this field is <code>true</code>.
*
* @see java.net.URLConnection#getDoInput()
* @see java.net.URLConnection#setDoInput(boolean)
*/
protected boolean doInput = true;
/**
* This variable is set by the <code>setDoOutput</code> method. Its
* value is returned by the <code>getDoInput</code> method.
* <p>
* A URL connection can be used for input and/or output. Setting the
* <code>doOutput</code> flag to <code>true</code> indicates
* that the application intends to write data to the URL connection.
* <p>
* The default value of this field is <code>false</code>.
*
* @see java.net.URLConnection#getDoOutput()
* @see java.net.URLConnection#setDoOutput(boolean)
*/
protected boolean doOutput = false;
private static boolean defaultAllowUserInteraction = false;
/**
* If <code>true</code>, this <code>URL</code> is being examined in
* a context in which it makes sense to allow user interactions such
* as popping up an authentication dialog. If <code>false</code>,
* then no user interaction is allowed.
* <p>
* The value of this field can be set by the
* <code>setAllowUserInteraction</code> method.
* Its value is returned by the
* <code>getAllowUserInteraction</code> method.
* Its default value is the value of the argument in the last invocation
* of the <code>setDefaultAllowUserInteraction</code> method.
*
* @see java.net.URLConnection#getAllowUserInteraction()
* @see java.net.URLConnection#setAllowUserInteraction(boolean)
* @see java.net.URLConnection#setDefaultAllowUserInteraction(boolean)
*/
protected boolean allowUserInteraction = defaultAllowUserInteraction;
private static boolean defaultUseCaches = true;
/**
* If <code>true</code>, the protocol is allowed to use caching
* whenever it can. If <code>false</code>, the protocol must always
* try to get a fresh copy of the object.
* <p>
* This field is set by the <code>setUseCaches</code> method. Its
* value is returned by the <code>getUseCaches</code> method.
* <p>
* Its default value is the value given in the last invocation of the
* <code>setDefaultUseCaches</code> method.
*
* @see java.net.URLConnection#setUseCaches(boolean)
* @see java.net.URLConnection#getUseCaches()
* @see java.net.URLConnection#setDefaultUseCaches(boolean)
*/
protected boolean useCaches = defaultUseCaches;
/**
* Some protocols support skipping the fetching of the object unless
* the object has been modified more recently than a certain time.
* <p>
* A nonzero value gives a time as the number of seconds since
* January 1, 1970, GMT. The object is fetched only if it has been
* modified more recently than that time.
* <p>
* This variable is set by the <code>setIfModifiedSince</code>
* method. Its value is returned by the
* <code>getIfModifiedSince</code> method.
* <p>
* The default value of this field is <code>0</code>, indicating
* that the fetching must always occur.
*
* @see java.net.URLConnection#getIfModifiedSince()
* @see java.net.URLConnection#setIfModifiedSince(long)
*/
protected long ifModifiedSince = 0;
/**
* If <code>false</code>, this connection object has not created a
* communications link to the specified URL. If <code>true</code>,
* the communications link has been established.
*/
protected boolean connected = false;
/**
* @since JDK1.1
*/
private static FileNameMap fileNameMap;
/**
* Returns the FileNameMap.
*
* @returns the FileNameMap
* @since JDK1.2
*/
public static FileNameMap getFileNameMap() {
return new FileNameMap() {
public String getContentTypeFor(String fileName) {
return fileNameMap.getContentTypeFor(fileName);
}
};
}
/**
* Sets the FileNameMap.
* <p>
* If there is a security manager, this method first calls
* the security manager's <code>checkSetFactory</code> method
* to ensure the operation is allowed.
* This could result in a SecurityException.
*
* @param map the FileNameMap to be set
* @exception SecurityException if a security manager exists and its
* <code>checkSetFactory</code> method doesn't allow the operation.
* @see SecurityManager#checkSetFactory
* @since JDK1.2
*/
public static void setFileNameMap(FileNameMap map) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) sm.checkSetFactory();
fileNameMap = map;
}
/**
* Opens a communications link to the resource referenced by this
* URL, if such a connection has not already been established.
* <p>
* If the <code>connect</code> method is called when the connection
* has already been opened (indicated by the <code>connected</code>
* field having the value <code>true</code>), the call is ignored.
* <p>
* URLConnection objects go through two phases: first they are
* created, then they are connected. After being created, and
* before being connected, various options can be specified
* (e.g., doInput and UseCaches). After connecting, it is an
* error to try to set them. Operations that depend on being
* connected, like getContentLength, will implicitly perform the
* connection, if necessary.
*
* @exception IOException if an I/O error occurs while opening the
* connection.
* @see java.net.URLConnection#connected */
abstract public void connect() throws IOException;
/**
* Constructs a URL connection to the specified URL. A connection to
* the object referenced by the URL is not created.
*
* @param url the specified URL.
*/
protected URLConnection(URL url) {
this.url = url;
}
/**
* Returns the value of this <code>URLConnection</code>'s <code>URL</code>
* field.
*
* @return the value of this <code>URLConnection</code>'s <code>URL</code>
* field.
* @see java.net.URLConnection#url
*/
public URL getURL() {
return url;
}
/**
* Returns the value of the <code>content-length</code> header field.
*
* @return the content length of the resource that this connection's URL
* references, or <code>-1</code> if the content length is
* not known.
*/
public int getContentLength() {
return getHeaderFieldInt("content-length", -1);
}
/**
* Returns the value of the <code>content-type</code> header field.
*
* @return the content type of the resource that the URL references,
* or <code>null</code> if not known.
* @see java.net.URLConnection#getHeaderField(java.lang.String)
*/
public String getContentType() {
return getHeaderField("content-type");
}
/**
* Returns the value of the <code>content-encoding</code> header field.
*
* @return the content encoding of the resource that the URL references,
* or <code>null</code> if not known.
* @see java.net.URLConnection#getHeaderField(java.lang.String)
*/
public String getContentEncoding() {
return getHeaderField("content-encoding");
}
/**
* Returns the value of the <code>expires</code> header field.
*
* @return the expiration date of the resource that this URL references,
* or 0 if not known. The value is the number of seconds since
* January 1, 1970 GMT.
* @see java.net.URLConnection#getHeaderField(java.lang.String)
*/
public long getExpiration() {
return getHeaderFieldDate("expires", 0);
}
/**
* Returns the value of the <code>date</code> header field.
*
* @return the sending date of the resource that the URL references,
* or <code>0</code> if not known. The value returned is the
* number of seconds since January 1, 1970 GMT.
* @see java.net.URLConnection#getHeaderField(java.lang.String)
*/
public long getDate() {
return getHeaderFieldDate("date", 0);
}
/**
* Returns the value of the <code>last-modified</code> header field.
* The result is the number of seconds since January 1, 1970 GMT.
*
* @return the date the resource referenced by this
* <code>URLConnection</code> was last modified, or 0 if not known.
* @see java.net.URLConnection#getHeaderField(java.lang.String)
*/
public long getLastModified() {
return getHeaderFieldDate("last-modified", 0);
}
/**
* Returns the name of the specified header field.
*
* @param name the name of a header field.
* @return the value of the named header field, or <code>null</code>
* if there is no such field in the header.
*/
public String getHeaderField(String name) {
return null;
}
/**
* Returns the value of the named field parsed as a number.
* <p>
* This form of <code>getHeaderField</code> exists because some
* connection types (e.g., <code>http-ng</code>) have pre-parsed
* headers. Classes for that connection type can override this method
* and short-circuit the parsing.
*
* @param name the name of the header field.
* @param Default the default value.
* @return the value of the named field, parsed as an integer. The
* <code>Default</code> value is returned if the field is
* missing or malformed.
*/
public int getHeaderFieldInt(String name, int Default) {
try {
return Integer.parseInt(getHeaderField(name));
} catch(Throwable t) {}
return Default;
}
/**
* Returns the value of the named field parsed as date.
* The result is the number of seconds since January 1, 1970 GMT
* represented by the named field.
* <p>
* This form of <code>getHeaderField</code> exists because some
* connection types (e.g., <code>http-ng</code>) have pre-parsed
* headers. Classes for that connection type can override this method
* and short-circuit the parsing.
*
* @param name the name of the header field.
* @param Default a default value.
* @return the value of the field, parsed as a date. The value of the
* <code>Default</code> argument is returned if the field is
* missing or malformed.
*/
public long getHeaderFieldDate(String name, long Default) {
try {
return Date.parse(getHeaderField(name));
} catch(Throwable t) {}
return Default;
}
/**
* Returns the key for the <code>n</code><sup>th</sup> header field.
*
* @param n an index.
* @return the key for the <code>n</code><sup>th</sup> header field,
* or <code>null</code> if there are fewer than <code>n</code>
* fields.
*/
public String getHeaderFieldKey(int n) {
return null;
}
/**
* Returns the value for the <code>n</code><sup>th</sup> header field.
* It returns <code>null</code> if there are fewer than
* <code>n</code> fields.
* <p>
* This method can be used in conjunction with the
* <code>getHeaderFieldKey</code> method to iterate through all
* the headers in the message.
*
* @param n an index.
* @return the value of the <code>n</code><sup>th</sup> header field.
* @see java.net.URLConnection#getHeaderFieldKey(int)
*/
public String getHeaderField(int n) {
return null;
}
/**
* Retrieves the contents of this URL connection.
* <p>
* This method first determines the content type of the object by
* calling the <code>getContentType</code> method. If this is
* the first time that the application has seen that specific content
* type, a content handler for that content type is created:
* <ol>
* <li>If the application has set up a content handler factory instance
* using the <code>setContentHandlerFactory</code> method, the
* <code>createContentHandler</code> method of that instance is called
* with the content type as an argument; the result is a content
* handler for that content type.
* <li>If no content handler factory has yet been set up, or if the
* factory's <code>createContentHandler</code> method returns
* <code>null</code>, then the application loads the class named:
* <blockquote><pre>
* sun.net.www.content.<<i>contentType</i>>
* </pre></blockquote>
* where <<i>contentType</i>> is formed by taking the
* content-type string, replacing all slash characters with a
* <code>period</code> ('.'), and all other non-alphanumeric characters
* with the underscore character '<code>_</code>'. The alphanumeric
* characters are specifically the 26 uppercase ASCII letters
* '<code>A</code>' through '<code>Z</code>', the 26 lowercase ASCII
* letters '<code>a</code>' through '<code>z</code>', and the 10 ASCII
* digits '<code>0</code>' through '<code>9</code>'. If the specified
* class does not exist, or is not a subclass of
* <code>ContentHandler</code>, then an
* <code>UnknownServiceException</code> is thrown.
* </ol>
*
* @return the object fetched. The <code>instanceOf</code> operation
* should be used to determine the specific kind of object
* returned.
* @exception IOException if an I/O error occurs while
* getting the content.
* @exception UnknownServiceException if the protocol does not support
* the content type.
* @see java.net.ContentHandlerFactory#createContentHandler(java.lang.String)
* @see java.net.URLConnection#getContentType()
* @see java.net.URLConnection#setContentHandlerFactory(java.net.ContentHandlerFactory)
*/
public Object getContent() throws IOException {
// Must call getInputStream before GetHeaderField gets called
// so that FileNotFoundException has a chance to be thrown up
// from here without being caught.
getInputStream();
return getContentHandler().getContent(this);
}
/**
* Returns a permission object representing the permission
* necessary to make the connection represented by this
* object. This method returns null if no permission is
* required to make the connection. By default, this method
* returns <code>java.security.AllPermission</code>. Subclasses
* should override this method and return the permission
* that best represents the permission required to make a
* a connection to the URL. For example, a <code>URLConnection</code>
* representing a <code>file:</code> URL would return a
* <code>java.io.FilePermission</code> object.
*
* <p>The permission returned may dependent upon the state of the
* connection. For example, the permission before connecting may be
* different from that after connecting. For example, an HTTP
* sever, say foo.com, may redirect the connection to a different
* host, say bar.com. Before connecting the permission returned by
* the connection will represent the permission needed to connect
* to foo.com, while the permission returned after connecting will
* be to bar.com.
*
* <p>Permissions are generally used for two purposes: to protect
* caches of objects obtained through URLConnections, and to check
* the right of a recipient to learn about a particular URL. In
* the first case, the permission should be obtained
* <em>after</em> the object has been obtained. For example, in an
* HTTP connection, this will represent the permission to connect
* to the host from which the data was ultimately fetched. In the
* second case, the permission should be obtained and tested
* <em>before</em> connecting.
*
* @return the permission object representing the permission
* necessary to make the connection represented by this
* URLConnection.
*
* @exception IOException if the computation of the permission
* requires network or file I/O and an exception occurs while
* computing it.
*/
public Permission getPermission() throws IOException {
return new java.security.AllPermission();
}
/**
* Returns an input stream that reads from this open connection.
*
* @return an input stream that reads from this open connection.
* @exception IOException if an I/O error occurs while
* creating the input stream.
* @exception UnknownServiceException if the protocol does not support
* input.
*/
public InputStream getInputStream() throws IOException {
throw new UnknownServiceException("protocol doesn't support input");
}
/**
* Returns an output stream that writes to this connection.
*
* @return an output stream that writes to this connection.
* @exception IOException if an I/O error occurs while
* creating the output stream.
* @exception UnknownServiceException if the protocol does not support
* output.
*/
public OutputStream getOutputStream() throws IOException {
throw new UnknownServiceException("protocol doesn't support output");
}
/**
* Returns a <code>String</code> representation of this URL connection.
*
* @return a string representation of this <code>URLConnection</code>.
*/
public String toString() {
return this.getClass().getName() + ":" + url;
}
/**
* Sets the value of the <code>doInput</code> field for this
* <code>URLConnection</code> to the specified value.
* <p>
* A URL connection can be used for input and/or output. Set the DoInput
* flag to true if you intend to use the URL connection for input,
* false if not. The default is true unless DoOutput is explicitly
* set to true, in which case DoInput defaults to false.
*
* @param value the new value.
* @see java.net.URLConnection#doInput
*/
public void setDoInput(boolean doinput) {
if (connected)
throw new IllegalAccessError("Already connected");
doInput = doinput;
}
/**
* Returns the value of this <code>URLConnection</code>'s
* <code>doInput</code> flag.
*
* @return the value of this <code>URLConnection</code>'s
* <code>doInput</code> flag.
* @see java.net.URLConnection#doInput
*/
public boolean getDoInput() {
return doInput;
}
/**
* Sets the value of the <code>doOutput</code> field for this
* <code>URLConnection</code> to the specified value.
* <p>
* A URL connection can be used for input and/or output. Set the DoOutput
* flag to true if you intend to use the URL connection for output,
* false if not. The default is false.
*
* @param value the new value.
* @see java.net.URLConnection#doOutput
*/
public void setDoOutput(boolean dooutput) {
if (connected)
throw new IllegalAccessError("Already connected");
doOutput = dooutput;
}
/**
* Returns the value of this <code>URLConnection</code>'s
* <code>doOutput</code> flag.
*
* @return the value of this <code>URLConnection</code>'s
* <code>doOutput</code> flag.
* @see java.net.URLConnection#doOutput
*/
public boolean getDoOutput() {
return doOutput;
}
/**
* Set the value of the <code>allowUserInteraction</code> field of
* this <code>URLConnection</code>.
*
* @param allowuserinteraction the new value.
* @see java.net.URLConnection#allowUserInteraction
*/
public void setAllowUserInteraction(boolean allowuserinteraction) {
if (connected)
throw new IllegalAccessError("Already connected");
allowUserInteraction = allowuserinteraction;
}
/**
* Returns the value of the <code>allowUserInteraction</code> field for
* this object.
*
* @return the value of the <code>allowUserInteraction</code> field for
* this object.
* @see java.net.URLConnection#allowUserInteraction
*/
public boolean getAllowUserInteraction() {
return allowUserInteraction;
}
/**
* Sets the default value of the
* <code>allowUserInteraction</code> field for all future
* <code>URLConnection</code> objects to the specified value.
*
* @param defaultallowuserinteraction the new value.
* @see java.net.URLConnection#allowUserInteraction
*/
public static void setDefaultAllowUserInteraction(boolean defaultallowuserinteraction) {
defaultAllowUserInteraction = defaultallowuserinteraction;
}
/**
* Returns the default value of the <code>allowUserInteraction</code>
* field.
* <p>
* Ths default is "sticky", being a part of the static state of all
* URLConnections. This flag applies to the next, and all following
* URLConnections that are created.
*
* @return the default value of the <code>allowUserInteraction</code>
* field.
* @see java.net.URLConnection#allowUserInteraction
*/
public static boolean getDefaultAllowUserInteraction() {
return defaultAllowUserInteraction;
}
/**
* Sets the value of the <code>useCaches</code> field of this
* <code>URLConnection</code> to the specified value.
* <p>
* Some protocols do caching of documents. Occasionally, it is important
* to be able to "tunnel through" and ignore the caches (e.g., the
* "reload" button in a browser). If the UseCaches flag on a connection
* is true, the connection is allowed to use whatever caches it can.
* If false, caches are to be ignored.
* The default value comes from DefaultUseCaches, which defaults to
* true.
*
* @see java.net.URLConnection#useCaches
*/
public void setUseCaches(boolean usecaches) {
if (connected)
throw new IllegalAccessError("Already connected");
useCaches = usecaches;
}
/**
* Returns the value of this <code>URLConnection</code>'s
* <code>useCaches</code> field.
*
* @return the value of this <code>URLConnection</code>'s
* <code>useCaches</code> field.
* @see java.net.URLConnection#useCaches
*/
public boolean getUseCaches() {
return useCaches;
}
/**
* Sets the value of the <code>ifModifiedSince</code> field of
* this <code>URLConnection</code> to the specified value.
*
* @param value the new value.
* @see java.net.URLConnection#ifModifiedSince
*/
public void setIfModifiedSince(long ifmodifiedsince) {
if (connected)
throw new IllegalAccessError("Already connected");
ifModifiedSince = ifmodifiedsince;
}
/**
* Returns the value of this object's <code>ifModifiedSince</code> field.
*
* @return the value of this object's <code>ifModifiedSince</code> field.
* @see java.net.URLConnection#ifModifiedSince
*/
public long getIfModifiedSince() {
return ifModifiedSince;
}
/**
* Returns the default value of a <code>URLConnection</code>'s
* <code>useCaches</code> flag.
* <p>
* Ths default is "sticky", being a part of the static state of all
* URLConnections. This flag applies to the next, and all following
* URLConnections that are created.
*
* @return the default value of a <code>URLConnection</code>'s
* <code>useCaches</code> flag.
* @see java.net.URLConnection#useCaches
*/
public boolean getDefaultUseCaches() {
return defaultUseCaches;
}
/**
* Sets the default value of the <code>useCaches</code> field to the
* specified value.
*
* @param defaultusecaches the new value.
* @see java.net.URLConnection#useCaches
*/
public void setDefaultUseCaches(boolean defaultusecaches) {
defaultUseCaches = defaultusecaches;
}
/**
* Sets the general request property.
*
* @param key the keyword by which the request is known
* (e.g., "<code>accept</code>").
* @param value the value associated with it.
*/
public void setRequestProperty(String key, String value) {
if (connected)
throw new IllegalAccessError("Already connected");
}
/**
* Returns the value of the named general request property for this
* connection.
*
* @return the value of the named general request property for this
* connection.
*/
public String getRequestProperty(String key) {
if (connected)
throw new IllegalAccessError("Already connected");
return null;
}
/**
* Sets the default value of a general request property. When a
* <code>URLConnection</code> is created, it is initialized with
* these properties.
*
* @param key the keyword by which the request is known
* (e.g., "<code>accept</code>").
* @param value the value associated with the key.
*/
public static void setDefaultRequestProperty(String key, String value) {
}
/**
* Returns the value of the default request property. Default request
* properties are set for every connection.
*
* @return the value of the default request property for the specified key.
* @see java.net.URLConnection#setDefaultRequestProperty(java.lang.String, java.lang.String)
*/
public static String getDefaultRequestProperty(String key) {
return null;
}
/**
* The ContentHandler factory.
*/
static ContentHandlerFactory factory;
/**
* Sets the <code>ContentHandlerFactory</code> of an
* application. It can be called at most once by an application.
* <p>
* The <code>ContentHandlerFactory</code> instance is used to
* construct a content handler from a content type
* <p>
* If there is a security manager, this method first calls
* the security manager's <code>checkSetFactory</code> method
* to ensure the operation is allowed.
* This could result in a SecurityException.
*
* @param fac the desired factory.
* @exception Error if the factory has already been defined.
* @exception SecurityException if a security manager exists and its
* <code>checkSetFactory</code> method doesn't allow the operation.
* @see java.net.ContentHandlerFactory
* @see java.net.URLConnection#getContent()
* @see SecurityManager#checkSetFactory
*/
public static synchronized void setContentHandlerFactory(ContentHandlerFactory fac) {
if (factory != null) {
throw new Error("factory already defined");
}
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkSetFactory();
}
factory = fac;
}
private static Hashtable handlers = new Hashtable();
private static final ContentHandler UnknownContentHandlerP = new UnknownContentHandler();
/**
* Gets the Content Handler appropriate for this connection.
* @param connection the connection to use.
*/
synchronized ContentHandler getContentHandler()
throws UnknownServiceException
{
String contentType = getContentType();
ContentHandler handler = null;
if (contentType == null)
throw new UnknownServiceException("no content-type");
try {
handler = (ContentHandler) handlers.get(contentType);
if (handler != null)
return handler;
} catch(Exception e) {
}
if (factory != null)
handler = factory.createContentHandler(contentType);
if (handler == null) {
try {
handler = lookupContentHandlerClassFor(contentType);
} catch(Exception e) {
e.printStackTrace();
handler = UnknownContentHandlerP;
}
handlers.put(contentType, handler);
}
return handler;
}
private static final String contentClassPrefix = "sun.net.www.content";
private static final String contentPathProp = "java.content.handler.pkgs";
/**
* Looks for a content handler in a user-defineable set of places.
* By default it looks in sun.net.www.content, but users can define a
* vertical-bar delimited set of class prefixes to search through in
* addition by defining the java.content.handler.pkgs property.
* The class name must be of the form:
* <pre>
* {package-prefix}.{major}.{minor}
* e.g.
* YoyoDyne.experimental.text.plain
* </pre>
*/
private ContentHandler lookupContentHandlerClassFor(String contentType)
throws InstantiationException, IllegalAccessException, ClassNotFoundException {
System.err.println("Content type: " + contentType);
String contentHandlerClassName = typeToPackageName(contentType);
System.err.println("contentHandlerClassName: " + contentHandlerClassName);
String contentHandlerPkgPrefixes =getContentHandlerPkgPrefixes();
System.err.println("contentHandlerPkgPrefixes: " + contentHandlerPkgPrefixes);
StringTokenizer packagePrefixIter =
new StringTokenizer(contentHandlerPkgPrefixes, "|");
while (packagePrefixIter.hasMoreTokens()) {
String packagePrefix = packagePrefixIter.nextToken().trim();
System.err.println("packagePrefix: " + packagePrefix);
try {
String name = packagePrefix + "." + contentHandlerClassName;
System.err.println("name: " + name);
ContentHandler handler =
(ContentHandler) Class.forName(name).newInstance();
return handler;
} catch(Exception e) {
System.err.println(e);
}
}
return UnknownContentHandlerP;
}
/**
* Utility function to map a MIME content type into an equivalent
* pair of class name components. For example: "text/html" would
* be returned as "text.html"
*/
private String typeToPackageName(String contentType) {
// make sure we canonicalize the class name: all lower case
contentType = contentType.toLowerCase();
int len = contentType.length();
char nm[] = new char[len];
contentType.getChars(0, len, nm, 0);
for (int i = 0; i < len; i++) {
char c = nm[i];
if (c == '/') {
nm[i] = '.';
} else if (!('A' <= c && c <= 'Z' ||
'a' <= c && c <= 'z' ||
'0' <= c && c <= '9')) {
nm[i] = '_';
}
}
return new String(nm);
}
/**
* Returns a vertical bar separated list of package prefixes for potential
* content handlers. Tries to get the java.content.handler.pkgs property
* to use as a set of package prefixes to search. Whether or not
* that property has been defined, the sun.net.www.content is always
* the last one on the returned package list.
*/
private String getContentHandlerPkgPrefixes() {
String packagePrefixList = (String) AccessController.doPrivileged(
new sun.security.action.GetPropertyAction(contentPathProp, ""));
if (packagePrefixList != "") {
packagePrefixList += "|";
}
return packagePrefixList + contentClassPrefix;
}
/**
* Tries to determine the content type of an object, based
* on the specified "file" component of a URL.
* This is a convenience method that can be used by
* subclasses that override the <code>getContentType</code> method.
*
* @param fname a filename.
* @return a guess as to what the content type of the object is,
* based upon its file name.
* @see java.net.URLConnection#getContentType()
*/
protected static String guessContentTypeFromName(String fname) {
String contentType = null;
if (fileNameMap != null) {
contentType = fileNameMap.getContentTypeFor(fname);
}
return contentType;
}
/**
* Tries to determine the type of an input stream based on the
* characters at the beginning of the input stream. This method can
* be used by subclasses that override the
* <code>getContentType</code> method.
* <p>
* Ideally, this routine would not be needed. But many
* <code>http</code> servers return the incorrect content type; in
* addition, there are many nonstandard extensions. Direct inspection
* of the bytes to determine the content type is often more accurate
* than believing the content type claimed by the <code>http</code> server.
*
* @param is an input stream that supports marks.
* @return a guess at the content type, or <code>null</code> if none
* can be determined.
* @exception IOException if an I/O error occurs while reading the
* input stream.
* @see java.io.InputStream#mark(int)
* @see java.io.InputStream#markSupported()
* @see java.net.URLConnection#getContentType()
*/
static public String guessContentTypeFromStream(InputStream is) throws IOException
{
is.mark(10);
int c1 = is.read();
int c2 = is.read();
int c3 = is.read();
int c4 = is.read();
int c5 = is.read();
int c6 = is.read();
int c7 = is.read();
int c8 = is.read();
is.reset();
if (c1 == 0xCA && c2 == 0xFE && c3 == 0xBA && c4 == 0xBE)
return "application/java-vm";
if (c1 == 0xAC && c2 == 0xED)
// next two bytes are version number, currently 0x00 0x05
return "application/x-java-serialized-object";
if (c1 == 'G' && c2 == 'I' && c3 == 'F' && c4 == '8')
return "image/gif";
if (c1 == '#' && c2 == 'd' && c3 == 'e' && c4 == 'f')
return "image/x-bitmap";
if (c1 == '!' && c2 == ' ' && c3 == 'X' && c4 == 'P' && c5 == 'M' && c6 == '2')
return "image/x-pixmap";
if (c1 == 0x2E && c2 == 0x73 && c3 == 0x6E && c4 == 0x64)
return "audio/basic"; // .au format, big endian
if (c1 == 0x64 && c2 == 0x6E && c3 == 0x73 && c4 == 0x2E)
return "audio/basic"; // .au format, little endian
if (c1 == '<')
if (c2 == '!'
|| ((c2 == 'h' && (c3 == 't' && c4 == 'm' && c5 == 'l' ||
c3 == 'e' && c4 == 'a' && c5 == 'd')
|| c2 == 'b' && c3 == 'o' && c4 == 'd' && c5 == 'y'))
|| ((c2 == 'H' && (c3 == 'T' && c4 == 'M' && c5 == 'L' ||
c3 == 'E' && c4 == 'A' && c5 == 'D')
|| c2 == 'B' && c3 == 'O' && c4 == 'D' && c5 == 'Y')))
return "text/html";
if (c1 == 0xFF && c2 == 0xD8 && c3 == 0xFF && c4 == 0xE0)
return "image/jpeg";
if (c1 == 0xFF && c2 == 0xD8 && c3 == 0xFF && c4 == 0xEE)
return "image/jpg";
if (c1 == 'R' && c2 == 'I' && c3 == 'F' && c4 == 'F')
/* I don't know if this is official but evidence
* suggests that .wav files start with "RIFF" - brown
*/
return "audio/x-wav";
if (c1 == 0xD0 && c2 == 0xCF && c3 == 0x11 && c4 == 0xE0 &&
c5 == 0xA1 && c6 == 0xB1 && c7 == 0x1A && c8 == 0xE1) {
/* Above is signature of Microsoft Structured Storage.
* Below this, could have tests for various SS entities.
* For now, just test for FlashPix.
*/
if (checkfpx(is))
return "image/vnd.fpx";
}
return null;
}
/**
* Check for FlashPix image data in InputStream is. Return true if
* the stream has FlashPix data, false otherwise. Before calling this
* method, the stream should have already been checked to be sure it
* contains Microsoft Structured Storage data.
*/
static private boolean checkfpx(InputStream is) throws IOException {
/* Test for FlashPix image data in Microsoft Structured Storage format.
* In general, should do this with calls to an SS implementation.
* Lacking that, need to dig via offsets to get to the FlashPix
* ClassID. Details:
*
* Offset to Fpx ClsID from beginning of stream should be:
*
* FpxClsidOffset = rootEntryOffset + clsidOffset
*
* where: clsidOffset = 0x50.
* rootEntryOffset = headerSize + sectorSize*sectDirStart
* + 128*rootEntryDirectory
*
* where: headerSize = 0x200 (always)
* sectorSize = 2 raised to power of uSectorShift,
* which is found in the header at
* offset 0x1E.
* sectDirStart = found in the header at offset 0x30.
* rootEntryDirectory = in general, should search for
* directory labelled as root.
* We will assume value of 0 (i.e.,
* rootEntry is in first directory)
*/
// Mark the stream so we can reset it. 0x100 is enough for the first
// few reads, but the mark will have to be reset and set again once
// the offset to the root directory entry is computed. That offset
// can be very large and isn't know until the stream has been read from
is.mark(0x100);
// Get the byte ordering located at 0x1E. 0xFE is Intel,
// 0xFF is other
long toSkip = (long)0x1C;
long skipped = 0;
while (skipped != toSkip) {
skipped += is.skip(toSkip - skipped);
}
long posn = skipped;
int byteOrder = is.read();
is.read();
posn+=2;
int uSectorShift;
if(byteOrder == 0xFE) {
uSectorShift = is.read();
uSectorShift += is.read() << 8;
}
else {
uSectorShift = is.read() << 8;
uSectorShift += is.read();
}
posn += 2;
toSkip = (long)0x30 - posn;
skipped = 0;
while (skipped != toSkip) {
skipped += is.skip(toSkip - skipped);
}
posn += skipped;
int sectDirStart;
if(byteOrder == 0xFE) {
sectDirStart = is.read();
sectDirStart += is.read()<<8;
sectDirStart += is.read()<<16;
sectDirStart += is.read()<<24;
}
else {
sectDirStart = is.read()<<24;
sectDirStart += is.read()<<16;
sectDirStart += is.read()<<8;
sectDirStart += is.read();
}
posn += 4;
is.reset(); // Reset back to the beginning
toSkip = (long)0x200 +
(long)((int)1<<uSectorShift)*sectDirStart + (long)0x50;
// How far can we skip? Is there any performance problem here?
// This skip can be fairly long, at least 0x4c650 in at least
// one case. Have to assume that the skip will fit in an int.
is.mark((int)toSkip+0x30); // Leave room to read whole root dir
skipped = 0;
while (skipped != toSkip) {
skipped += is.skip(toSkip - skipped);
}
/* should be at beginning of ClassID, which is as follows
* (in Intel byte order):
* 00 67 61 56 54 C1 CE 11 85 53 00 AA 00 A1 F9 5B
*
* This is stored from Windows as long,short,short,char[8]
* so for byte order changes, the order only changes for
* the first 8 bytes in the ClassID.
*
* Test against this, ignoring second byte (Intel) since
* this could change depending on part of Fpx file we have.
*/
int c[] = new int[16];
for (int i=0; i<16; i++) c[i] = is.read();
// intel byte order
if (byteOrder == 0xFE &&
c[0] == 0x00 && c[2] == 0x61 && c[3] == 0x56 &&
c[4] == 0x54 && c[5] == 0xC1 && c[6] == 0xCE &&
c[7] == 0x11 && c[8] == 0x85 && c[9] == 0x53 &&
c[10]== 0x00 && c[11]== 0xAA && c[12]== 0x00 &&
c[13]== 0xA1 && c[14]== 0xF9 && c[15]== 0x5B) {
is.reset();
return true;
}
// non-intel byte order
else if (c[3] == 0x00 && c[1] == 0x61 && c[0] == 0x56 &&
c[5] == 0x54 && c[4] == 0xC1 && c[7] == 0xCE &&
c[6] == 0x11 && c[8] == 0x85 && c[9] == 0x53 &&
c[10]== 0x00 && c[11]== 0xAA && c[12]== 0x00 &&
c[13]== 0xA1 && c[14]== 0xF9 && c[15]== 0x5B) {
is.reset();
return true;
}
is.reset();
return false;
}
}
class UnknownContentHandler extends ContentHandler {
public Object getContent(URLConnection uc) throws IOException {
return uc.getInputStream();
}
}
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