/* * Copyright (C) 2014 The Android Open Source Project * Copyright (c) 1995, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ 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.util.Collections; import java.util.Map; import java.util.List; import java.security.Permission; import java.security.AccessController; import sun.security.util.SecurityConstants; import sun.net.www.MessageHeader; /** * The abstract class URLConnection 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: *

*

* * * * *
openConnection()connect()
Manipulate parameters that affect the connection to the remote * resource.Interact with the resource; query header fields and * contents.
* ----------------------------> *
time
* *
    *
  1. The connection object is created by invoking the * openConnection method on a URL. *
  2. The setup parameters and general request properties are manipulated. *
  3. The actual connection to the remote object is made, using the * connect method. *
  4. The remote object becomes available. The header fields and the contents * of the remote object can be accessed. *
*

* The setup parameters are modified using the following methods: *

*

* and the general request properties are modified using the method: *

*

* Default values for the AllowUserInteraction and * UseCaches parameters can be set using the methods * setDefaultAllowUserInteraction and * setDefaultUseCaches. *

* Each of the above set methods has a corresponding * get 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. *

* The following methods are used to access the header fields and * the contents after the connection is made to the remote object: *

*

* Certain header fields are accessed frequently. The methods: *

*

* provide convenient access to these fields. The * getContentType method is used by the * getContent method to determine the type of the remote * object; subclasses may find it convenient to override the * getContentType method. *

* 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: getInputStream and getContent, * which are mirrored in the URL class by convenience methods. *

* More information on the request properties and header fields of * an http connection can be found at: *

 * http://www.ietf.org/rfc/rfc2616.txt
 * 
* * Note about fileNameMap: In versions prior to JDK 1.1.6, * field fileNameMap of URLConnection was public. * In JDK 1.1.6 and later, fileNameMap 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 * Compatibility page. * * Invoking the close() methods on the InputStream or OutputStream of an * URLConnection after a request may free network resources associated with this * instance, unless particular protocol specifications specify different behaviours * for it. * * @author James Gosling * @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#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. *

* The value of this field can be accessed by the * getURL method. *

* The default value of this variable is the value of the URL * argument in the URLConnection constructor. * * @see java.net.URLConnection#getURL() * @see java.net.URLConnection#url */ protected URL url; /** * This variable is set by the setDoInput method. Its * value is returned by the getDoInput method. *

* A URL connection can be used for input and/or output. Setting the * doInput flag to true indicates that * the application intends to read data from the URL connection. *

* The default value of this field is true. * * @see java.net.URLConnection#getDoInput() * @see java.net.URLConnection#setDoInput(boolean) */ protected boolean doInput = true; /** * This variable is set by the setDoOutput method. Its * value is returned by the getDoOutput method. *

* A URL connection can be used for input and/or output. Setting the * doOutput flag to true indicates * that the application intends to write data to the URL connection. *

* The default value of this field is false. * * @see java.net.URLConnection#getDoOutput() * @see java.net.URLConnection#setDoOutput(boolean) */ protected boolean doOutput = false; private static boolean defaultAllowUserInteraction = false; /** * If true, this URL is being examined in * a context in which it makes sense to allow user interactions such * as popping up an authentication dialog. If false, * then no user interaction is allowed. *

* The value of this field can be set by the * setAllowUserInteraction method. * Its value is returned by the * getAllowUserInteraction method. * Its default value is the value of the argument in the last invocation * of the setDefaultAllowUserInteraction 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 true, the protocol is allowed to use caching * whenever it can. If false, the protocol must always * try to get a fresh copy of the object. *

* This field is set by the setUseCaches method. Its * value is returned by the getUseCaches method. *

* Its default value is the value given in the last invocation of the * setDefaultUseCaches 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. *

* A nonzero value gives a time as the number of milliseconds since * January 1, 1970, GMT. The object is fetched only if it has been * modified more recently than that time. *

* This variable is set by the setIfModifiedSince * method. Its value is returned by the * getIfModifiedSince method. *

* The default value of this field is 0, indicating * that the fetching must always occur. * * @see java.net.URLConnection#getIfModifiedSince() * @see java.net.URLConnection#setIfModifiedSince(long) */ protected long ifModifiedSince = 0; /** * If false, this connection object has not created a * communications link to the specified URL. If true, * the communications link has been established. */ protected boolean connected = false; /** * @since 1.5 */ private int connectTimeout; private int readTimeout; /** * @since 1.6 */ private MessageHeader requests; /** * @since JDK1.1 */ private static FileNameMap fileNameMap; /** * Loads filename map (a mimetable) from a data file. It will * first try to load the user-specific table, defined * by "content.types.user.table" property. If that fails, * it tries to load the default built-in table at * lib/content-types.properties under java home. * * @return the FileNameMap * @since 1.2 * @see #setFileNameMap(java.net.FileNameMap) */ public static synchronized FileNameMap getFileNameMap() { if (fileNameMap == null) { fileNameMap = new DefaultFileNameMap(); } return fileNameMap; } /** * Sets the FileNameMap. *

* 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. * * @param map the FileNameMap to be set * @exception SecurityException if a security manager exists and its * checkSetFactory method doesn't allow the operation. * @see SecurityManager#checkSetFactory * @see #getFileNameMap() * @since 1.2 */ 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. *

* If the connect method is called when the connection * has already been opened (indicated by the connected * field having the value true), the call is ignored. *

* 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. * * @throws SocketTimeoutException if the timeout expires before * the connection can be established * @exception IOException if an I/O error occurs while opening the * connection. * @see java.net.URLConnection#connected * @see #getConnectTimeout() * @see #setConnectTimeout(int) */ abstract public void connect() throws IOException; /** * Sets a specified timeout value, in milliseconds, to be used * when opening a communications link to the resource referenced * by this URLConnection. If the timeout expires before the * connection can be established, a * java.net.SocketTimeoutException is raised. A timeout of zero is * interpreted as an infinite timeout. *

Some non-standard implmentation of this method may ignore * the specified timeout. To see the connect timeout set, please * call getConnectTimeout(). * * @param timeout an int that specifies the connect * timeout value in milliseconds * @throws IllegalArgumentException if the timeout parameter is negative * * @see #getConnectTimeout() * @see #connect() * @since 1.5 */ public void setConnectTimeout(int timeout) { if (timeout < 0) { throw new IllegalArgumentException("timeout can not be negative"); } connectTimeout = timeout; } /** * Returns setting for connect timeout. *

* 0 return implies that the option is disabled * (i.e., timeout of infinity). * * @return an int that indicates the connect timeout * value in milliseconds * @see #setConnectTimeout(int) * @see #connect() * @since 1.5 */ public int getConnectTimeout() { return connectTimeout; } /** * Sets the read timeout to a specified timeout, in * milliseconds. A non-zero value specifies the timeout when * reading from Input stream when a connection is established to a * resource. If the timeout expires before there is data available * for read, a java.net.SocketTimeoutException is raised. A * timeout of zero is interpreted as an infinite timeout. * *

Some non-standard implementation of this method ignores the * specified timeout. To see the read timeout set, please call * getReadTimeout(). * * @param timeout an int that specifies the timeout * value to be used in milliseconds * @throws IllegalArgumentException if the timeout parameter is negative * * @see #getReadTimeout() * @see InputStream#read() * @since 1.5 */ public void setReadTimeout(int timeout) { if (timeout < 0) { throw new IllegalArgumentException("timeout can not be negative"); } readTimeout = timeout; } /** * Returns setting for read timeout. 0 return implies that the * option is disabled (i.e., timeout of infinity). * * @return an int that indicates the read timeout * value in milliseconds * * @see #setReadTimeout(int) * @see InputStream#read() * @since 1.5 */ public int getReadTimeout() { return readTimeout; } /** * 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 URLConnection's URL * field. * * @return the value of this URLConnection's URL * field. * @see java.net.URLConnection#url */ public URL getURL() { return url; } /** * Returns the value of the content-length header field. *

* Note: {@link #getContentLengthLong() getContentLengthLong()} * should be preferred over this method, since it returns a {@code long} * instead and is therefore more portable.

* * @return the content length of the resource that this connection's URL * references, {@code -1} if the content length is not known, * or if the content length is greater than Integer.MAX_VALUE. */ public int getContentLength() { long l = getContentLengthLong(); if (l > Integer.MAX_VALUE) return -1; return (int) l; } /** * Returns the value of the content-length header field as a * long. * * @return the content length of the resource that this connection's URL * references, or -1 if the content length is * not known. * @since 7.0 */ public long getContentLengthLong() { return getHeaderFieldLong("content-length", -1); } /** * Returns the value of the content-type header field. * * @return the content type of the resource that the URL references, * or null if not known. * @see java.net.URLConnection#getHeaderField(java.lang.String) */ public String getContentType() { return getHeaderField("content-type"); } /** * Returns the value of the content-encoding header field. * * @return the content encoding of the resource that the URL references, * or null if not known. * @see java.net.URLConnection#getHeaderField(java.lang.String) */ public String getContentEncoding() { return getHeaderField("content-encoding"); } /** * Returns the value of the expires header field. * * @return the expiration date of the resource that this URL references, * or 0 if not known. The value is the number of milliseconds 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 date header field. * * @return the sending date of the resource that the URL references, * or 0 if not known. The value returned is the * number of milliseconds 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 last-modified header field. * The result is the number of milliseconds since January 1, 1970 GMT. * * @return the date the resource referenced by this * URLConnection 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 value of the named header field. *

* If called on a connection that sets the same header multiple times * with possibly different values, only the last value is returned. * * * @param name the name of a header field. * @return the value of the named header field, or null * if there is no such field in the header. */ public String getHeaderField(String name) { return null; } /** * Returns an unmodifiable Map of the header fields. * The Map keys are Strings that represent the * response-header field names. Each Map value is an * unmodifiable List of Strings that represents * the corresponding field values. * * @return a Map of header fields * @since 1.4 */ public Map> getHeaderFields() { return Collections.EMPTY_MAP; } /** * Returns the value of the named field parsed as a number. *

* This form of getHeaderField exists because some * connection types (e.g., http-ng) 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 * Default value is returned if the field is * missing or malformed. */ public int getHeaderFieldInt(String name, int Default) { String value = getHeaderField(name); try { return Integer.parseInt(value); } catch (Exception e) { } return Default; } /** * Returns the value of the named field parsed as a number. *

* This form of getHeaderField exists because some * connection types (e.g., http-ng) 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 a long. The * Default value is returned if the field is * missing or malformed. * @since 7.0 */ public long getHeaderFieldLong(String name, long Default) { String value = getHeaderField(name); try { return Long.parseLong(value); } catch (Exception e) { } return Default; } /** * Returns the value of the named field parsed as date. * The result is the number of milliseconds since January 1, 1970 GMT * represented by the named field. *

* This form of getHeaderField exists because some * connection types (e.g., http-ng) 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 * Default argument is returned if the field is * missing or malformed. */ public long getHeaderFieldDate(String name, long Default) { String value = getHeaderField(name); try { return Date.parse(value); } catch (Exception e) { } return Default; } /** * Returns the key for the nth header field. * It returns null if there are fewer than n+1 fields. * * @param n an index, where n>=0 * @return the key for the nth header field, * or null if there are fewer than n+1 * fields. */ public String getHeaderFieldKey(int n) { return null; } /** * Returns the value for the nth header field. * It returns null if there are fewer than * n+1fields. *

* This method can be used in conjunction with the * {@link #getHeaderFieldKey(int) getHeaderFieldKey} method to iterate through all * the headers in the message. * * @param n an index, where n>=0 * @return the value of the nth header field * or null if there are fewer than n+1 fields * @see java.net.URLConnection#getHeaderFieldKey(int) */ public String getHeaderField(int n) { return null; } /** * Retrieves the contents of this URL connection. *

* This method first determines the content type of the object by * calling the getContentType 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: *

    *
  1. If the application has set up a content handler factory instance * using the setContentHandlerFactory method, the * createContentHandler method of that instance is called * with the content type as an argument; the result is a content * handler for that content type. *
  2. If no content handler factory has yet been set up, or if the * factory's createContentHandler method returns * null, then the application loads the class named: *
         *         sun.net.www.content.<contentType>
         *     
    * where <contentType> is formed by taking the * content-type string, replacing all slash characters with a * period ('.'), and all other non-alphanumeric characters * with the underscore character '_'. The alphanumeric * characters are specifically the 26 uppercase ASCII letters * 'A' through 'Z', the 26 lowercase ASCII * letters 'a' through 'z', and the 10 ASCII * digits '0' through '9'. If the specified * class does not exist, or is not a subclass of * ContentHandler, then an * UnknownServiceException is thrown. *
* * @return the object fetched. The instanceof operator * 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); } /** * Retrieves the contents of this URL connection. * * @param classes the Class array * indicating the requested types * @return the object fetched that is the first match of the type * specified in the classes array. null if none of * the requested types are supported. * The instanceof operator 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.URLConnection#getContent() * @see java.net.ContentHandlerFactory#createContentHandler(java.lang.String) * @see java.net.URLConnection#getContent(java.lang.Class[]) * @see java.net.URLConnection#setContentHandlerFactory(java.net.ContentHandlerFactory) * @since 1.3 */ public Object getContent(Class[] classes) 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, classes); } /** * 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 java.security.AllPermission. 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 URLConnection * representing a file: URL would return a * java.io.FilePermission object. * *

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. * *

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 * after 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 * before 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 SecurityConstants.ALL_PERMISSION; } /** * Returns an input stream that reads from this open connection. * * A SocketTimeoutException can be thrown when reading from the * returned input stream if the read timeout expires before data * is available for read. * * @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. * @see #setReadTimeout(int) * @see #getReadTimeout() */ 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 String representation of this URL connection. * * @return a string representation of this URLConnection. */ public String toString() { return this.getClass().getName() + ":" + url; } /** * Sets the value of the doInput field for this * URLConnection to the specified value. *

* 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. * * @param doinput the new value. * @throws IllegalStateException if already connected * @see java.net.URLConnection#doInput * @see #getDoInput() */ public void setDoInput(boolean doinput) { if (connected) throw new IllegalStateException("Already connected"); doInput = doinput; } /** * Returns the value of this URLConnection's * doInput flag. * * @return the value of this URLConnection's * doInput flag. * @see #setDoInput(boolean) */ public boolean getDoInput() { return doInput; } /** * Sets the value of the doOutput field for this * URLConnection to the specified value. *

* 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 dooutput the new value. * @throws IllegalStateException if already connected * @see #getDoOutput() */ public void setDoOutput(boolean dooutput) { if (connected) throw new IllegalStateException("Already connected"); doOutput = dooutput; } /** * Returns the value of this URLConnection's * doOutput flag. * * @return the value of this URLConnection's * doOutput flag. * @see #setDoOutput(boolean) */ public boolean getDoOutput() { return doOutput; } /** * Set the value of the allowUserInteraction field of * this URLConnection. * * @param allowuserinteraction the new value. * @throws IllegalStateException if already connected * @see #getAllowUserInteraction() */ public void setAllowUserInteraction(boolean allowuserinteraction) { if (connected) throw new IllegalStateException("Already connected"); allowUserInteraction = allowuserinteraction; } /** * Returns the value of the allowUserInteraction field for * this object. * * @return the value of the allowUserInteraction field for * this object. * @see #setAllowUserInteraction(boolean) */ public boolean getAllowUserInteraction() { return allowUserInteraction; } /** * Sets the default value of the * allowUserInteraction field for all future * URLConnection objects to the specified value. * * @param defaultallowuserinteraction the new value. * @see #getDefaultAllowUserInteraction() */ public static void setDefaultAllowUserInteraction(boolean defaultallowuserinteraction) { defaultAllowUserInteraction = defaultallowuserinteraction; } /** * Returns the default value of the allowUserInteraction * field. *

* 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 allowUserInteraction * field. * @see #setDefaultAllowUserInteraction(boolean) */ public static boolean getDefaultAllowUserInteraction() { return defaultAllowUserInteraction; } /** * Sets the value of the useCaches field of this * URLConnection to the specified value. *

* 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. * * @param usecaches a boolean indicating whether * or not to allow caching * @throws IllegalStateException if already connected * @see #getUseCaches() */ public void setUseCaches(boolean usecaches) { if (connected) throw new IllegalStateException("Already connected"); useCaches = usecaches; } /** * Returns the value of this URLConnection's * useCaches field. * * @return the value of this URLConnection's * useCaches field. * @see #setUseCaches(boolean) */ public boolean getUseCaches() { return useCaches; } /** * Sets the value of the ifModifiedSince field of * this URLConnection to the specified value. * * @param ifmodifiedsince the new value. * @throws IllegalStateException if already connected * @see #getIfModifiedSince() */ public void setIfModifiedSince(long ifmodifiedsince) { if (connected) throw new IllegalStateException("Already connected"); ifModifiedSince = ifmodifiedsince; } /** * Returns the value of this object's ifModifiedSince field. * * @return the value of this object's ifModifiedSince field. * @see #setIfModifiedSince(long) */ public long getIfModifiedSince() { return ifModifiedSince; } /** * Returns the default value of a URLConnection's * useCaches flag. *

* 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 URLConnection's * useCaches flag. * @see #setDefaultUseCaches(boolean) */ public boolean getDefaultUseCaches() { return defaultUseCaches; } /** * Sets the default value of the useCaches field to the * specified value. * * @param defaultusecaches the new value. * @see #getDefaultUseCaches() */ public void setDefaultUseCaches(boolean defaultusecaches) { defaultUseCaches = defaultusecaches; } /** * Sets the general request property. If a property with the key already * exists, overwrite its value with the new value. * *

NOTE: HTTP requires all request properties which can * legally have multiple instances with the same key * to use a comma-seperated list syntax which enables multiple * properties to be appended into a single property. * * @param key the keyword by which the request is known * (e.g., "Accept"). * @param value the value associated with it. * @throws IllegalStateException if already connected * @throws NullPointerException if key is null * @see #getRequestProperty(java.lang.String) */ public void setRequestProperty(String key, String value) { if (connected) throw new IllegalStateException("Already connected"); if (key == null) throw new NullPointerException ("key is null"); if (requests == null) requests = new MessageHeader(); requests.set(key, value); } /** * Adds a general request property specified by a * key-value pair. This method will not overwrite * existing values associated with the same key. * * @param key the keyword by which the request is known * (e.g., "Accept"). * @param value the value associated with it. * @throws IllegalStateException if already connected * @throws NullPointerException if key is null * @see #getRequestProperties() * @since 1.4 */ public void addRequestProperty(String key, String value) { if (connected) throw new IllegalStateException("Already connected"); if (key == null) throw new NullPointerException ("key is null"); if (requests == null) requests = new MessageHeader(); requests.add(key, value); } /** * Returns the value of the named general request property for this * connection. * * @param key the keyword by which the request is known (e.g., "Accept"). * @return the value of the named general request property for this * connection. If key is null, then null is returned. * @throws IllegalStateException if already connected * @see #setRequestProperty(java.lang.String, java.lang.String) */ public String getRequestProperty(String key) { if (connected) throw new IllegalStateException("Already connected"); if (requests == null) return null; return requests.findValue(key); } /** * Returns an unmodifiable Map of general request * properties for this connection. The Map keys * are Strings that represent the request-header * field names. Each Map value is a unmodifiable List * of Strings that represents the corresponding * field values. * * @return a Map of the general request properties for this connection. * @throws IllegalStateException if already connected * @since 1.4 */ public Map> getRequestProperties() { if (connected) throw new IllegalStateException("Already connected"); if (requests == null) return Collections.EMPTY_MAP; return requests.getHeaders(null); } /** * Sets the default value of a general request property. When a * URLConnection is created, it is initialized with * these properties. * * @param key the keyword by which the request is known * (e.g., "Accept"). * @param value the value associated with the key. * * @see java.net.URLConnection#setRequestProperty(java.lang.String,java.lang.String) * * @deprecated The instance specific setRequestProperty method * should be used after an appropriate instance of URLConnection * is obtained. Invoking this method will have no effect. * * @see #getDefaultRequestProperty(java.lang.String) */ @Deprecated public static void setDefaultRequestProperty(String key, String value) { } /** * Returns the value of the default request property. Default request * properties are set for every connection. * * @param key the keyword by which the request is known (e.g., "Accept"). * @return the value of the default request property * for the specified key. * * @see java.net.URLConnection#getRequestProperty(java.lang.String) * * @deprecated The instance specific getRequestProperty method * should be used after an appropriate instance of URLConnection * is obtained. * * @see #setDefaultRequestProperty(java.lang.String, java.lang.String) */ @Deprecated public static String getDefaultRequestProperty(String key) { return null; } /** * The ContentHandler factory. */ static ContentHandlerFactory factory; /** * Sets the ContentHandlerFactory of an * application. It can be called at most once by an application. *

* The ContentHandlerFactory instance is used to * construct a content handler from a content type *

* 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. * * @param fac the desired factory. * @exception Error if the factory has already been defined. * @exception SecurityException if a security manager exists and its * checkSetFactory 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(); /** * Gets the Content Handler appropriate for this connection. * @param connection the connection to use. */ synchronized ContentHandler getContentHandler() throws IOException { String contentType = stripOffParameters(getContentType()); ContentHandler handler = null; if (contentType == null) { if ((contentType = guessContentTypeFromName(url.getFile())) == null) { contentType = guessContentTypeFromStream(getInputStream()); } } if (contentType == null) { return UnknownContentHandler.INSTANCE; } 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 = UnknownContentHandler.INSTANCE; } handlers.put(contentType, handler); } return handler; } /* * Media types are in the format: type/subtype*(; parameter). * For looking up the content handler, we should ignore those * parameters. */ private String stripOffParameters(String contentType) { if (contentType == null) return null; int index = contentType.indexOf(';'); if (index > 0) return contentType.substring(0, index); else return contentType; } 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: *

     *     {package-prefix}.{major}.{minor}
     * e.g.
     *     YoyoDyne.experimental.text.plain
     * 
*/ private ContentHandler lookupContentHandlerClassFor(String contentType) throws InstantiationException, IllegalAccessException, ClassNotFoundException { String contentHandlerClassName = typeToPackageName(contentType); String contentHandlerPkgPrefixes =getContentHandlerPkgPrefixes(); StringTokenizer packagePrefixIter = new StringTokenizer(contentHandlerPkgPrefixes, "|"); while (packagePrefixIter.hasMoreTokens()) { String packagePrefix = packagePrefixIter.nextToken().trim(); try { String clsName = packagePrefix + "." + contentHandlerClassName; 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) { ContentHandler handler = (ContentHandler)cls.newInstance(); return handler; } } catch(Exception e) { } } return UnknownContentHandler.INSTANCE; } /** * 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 = 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 getContentType 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() */ public static String guessContentTypeFromName(String fname) { return getFileNameMap().getContentTypeFor(fname); } /** * 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 * getContentType method. *

* Ideally, this routine would not be needed. But many * http 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 http server. * * @param is an input stream that supports marks. * @return a guess at the content type, or null 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 { // If we can't read ahead safely, just give up on guessing if (!is.markSupported()) return null; is.mark(16); 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(); int c9 = is.read(); int c10 = is.read(); int c11 = is.read(); int c12 = is.read(); int c13 = is.read(); int c14 = is.read(); int c15 = is.read(); int c16 = 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 == '<') { 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 (c2 == '?' && c3 == 'x' && c4 == 'm' && c5 == 'l' && c6 == ' ') { return "application/xml"; } } // big and little (identical) endian UTF-8 encodings, with BOM if (c1 == 0xef && c2 == 0xbb && c3 == 0xbf) { if (c4 == '<' && c5 == '?' && c6 == 'x') { return "application/xml"; } } // big and little endian UTF-16 encodings, with byte order mark if (c1 == 0xfe && c2 == 0xff) { if (c3 == 0 && c4 == '<' && c5 == 0 && c6 == '?' && c7 == 0 && c8 == 'x') { return "application/xml"; } } if (c1 == 0xff && c2 == 0xfe) { if (c3 == '<' && c4 == 0 && c5 == '?' && c6 == 0 && c7 == 'x' && c8 == 0) { return "application/xml"; } } // big and little endian UTF-32 encodings, with BOM if (c1 == 0x00 && c2 == 0x00 && c3 == 0xfe && c4 == 0xff) { if (c5 == 0 && c6 == 0 && c7 == 0 && c8 == '<' && c9 == 0 && c10 == 0 && c11 == 0 && c12 == '?' && c13 == 0 && c14 == 0 && c15 == 0 && c16 == 'x') { return "application/xml"; } } if (c1 == 0xff && c2 == 0xfe && c3 == 0x00 && c4 == 0x00) { if (c5 == '<' && c6 == 0 && c7 == 0 && c8 == 0 && c9 == '?' && c10 == 0 && c11 == 0 && c12 == 0 && c13 == 'x' && c14 == 0 && c15 == 0 && c16 == 0) { return "application/xml"; } } 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 == 137 && c2 == 80 && c3 == 78 && c4 == 71 && c5 == 13 && c6 == 10 && c7 == 26 && c8 == 10) { return "image/png"; } if (c1 == 0xFF && c2 == 0xD8 && c3 == 0xFF) { if (c4 == 0xE0) { return "image/jpeg"; } /** * File format used by digital cameras to store images. * Exif Format can be read by any application supporting * JPEG. Exif Spec can be found at: * http://www.pima.net/standards/it10/PIMA15740/Exif_2-1.PDF */ if ((c4 == 0xE1) && (c7 == 'E' && c8 == 'x' && c9 == 'i' && c10 =='f' && c11 == 0)) { return "image/jpeg"; } if (c4 == 0xEE) { return "image/jpg"; } } 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"; } } 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 == '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"; } 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 posn; if ((posn = skipForward(is, toSkip)) < toSkip) { is.reset(); return false; } int c[] = new int[16]; if (readBytes(c, 2, is) < 0) { is.reset(); return false; } int byteOrder = c[0]; posn+=2; int uSectorShift; if (readBytes(c, 2, is) < 0) { is.reset(); return false; } if(byteOrder == 0xFE) { uSectorShift = c[0]; uSectorShift += c[1] << 8; } else { uSectorShift = c[0] << 8; uSectorShift += c[1]; } posn += 2; toSkip = (long)0x30 - posn; long skipped = 0; if ((skipped = skipForward(is, toSkip)) < toSkip) { is.reset(); return false; } posn += skipped; if (readBytes(c, 4, is) < 0) { is.reset(); return false; } int sectDirStart; if(byteOrder == 0xFE) { sectDirStart = c[0]; sectDirStart += c[1] << 8; sectDirStart += c[2] << 16; sectDirStart += c[3] << 24; } else { sectDirStart = c[0] << 24; sectDirStart += c[1] << 16; sectDirStart += c[2] << 8; sectDirStart += c[3]; } posn += 4; is.reset(); // Reset back to the beginning toSkip = 0x200L + (long)(1<