fileconnection.html

j2me 中从本地读取数据JSR075 API 包括 FileConnection 等

											<DD>
												<CODE>java.lang.SecurityException</CODE> - if the security of the application 
												does not have read access to the root volume.
												<DD>
													<CODE><A HREF="../../../../javax/microedition/io/file/IllegalModeException.html">IllegalModeException</A></CODE>
													- if the application does have read access to the directory but has opened the 
													connection in <code>Connector.WRITE</code> mode.
													<DD>
														<CODE><A HREF="../../../../javax/microedition/io/file/ConnectionClosedException.html">ConnectionClosedException</A></CODE>
														- if the connection is closed.</DD></DL>
						</DD>
			</DL>
			<HR>
			<A NAME="usedSize()"><!-- --></A><H3>
				usedSize</H3>
			<PRE>
public long <B>usedSize</B>()</PRE>
			<DL>
				<DD>
					Determines the used memory of a file system the connection's target resides on. 
					This may only be an estimate and may vary based on platform-specific file 
					system blocking and metadata information.
					<P></P>
					<DD>
						<DL>
						</DL>
						<DD>
							<DL>
								<DT><B>Returns:</B><DD>The used size of bytes on a file system, or -1 if the file 
										system is not accessible. <DT><B>Throws:</B>
											<DD>
												<CODE>java.lang.SecurityException</CODE> - if the security of the application 
												does not have read access to the root volume.
												<DD>
													<CODE><A HREF="../../../../javax/microedition/io/file/IllegalModeException.html">IllegalModeException</A></CODE>
													- if the application does have read access to the directory but has opened the 
													connection in <code>Connector.WRITE</code> mode.
													<DD>
														<CODE><A HREF="../../../../javax/microedition/io/file/ConnectionClosedException.html">ConnectionClosedException</A></CODE>
														- if the connection is closed.</DD></DL>
						</DD>
			</DL>
			<HR>
			<A NAME="directorySize(boolean)"><!-- --></A><H3>
				directorySize</H3>
			<PRE>
public long <B>directorySize</B>(boolean&nbsp;includeSubDirs)
                   throws java.io.IOException</PRE>
			<DL>
				<DD>
					Determines the size in bytes on a file system of all of the files that are 
					contained in a directory.
					<P></P>
					<DD>
						<DL>
						</DL>
						<DD>
							<DL>
								<DT><B>Returns:</B><DD>The size in bytes occupied by the files included in the 
										directory, or -1 if the directory does not exist or is not accessible. <DT><B>Throws:</B>
											<DD>
												<CODE>java.io.IOException</CODE> - if the method is invoked on a file.
												<DD>
													<CODE>java.lang.SecurityException</CODE> - if the security of the application 
													does not have read access for the directory.
													<DD>
														<CODE><A HREF="../../../../javax/microedition/io/file/IllegalModeException.html">IllegalModeException</A></CODE>
														- if the application does have read access to the directory but has opened the 
														connection in <code>Connector.WRITE</code> mode.
														<DD>
															<CODE><A HREF="../../../../javax/microedition/io/file/ConnectionClosedException.html">ConnectionClosedException</A></CODE>
															- if the connection is closed.</DD></DL>
						</DD>
			</DL>
			<HR>
			<A NAME="fileSize()"><!-- --></A><H3>
				fileSize</H3>
			<PRE>
public long <B>fileSize</B>()
              throws java.io.IOException</PRE>
			<DL>
				<DD>
					Determines the size of a file on the file system. The size of a file always 
					represents the number of bytes contained in the file; there is no pre-allocated 
					but empty space in a file. Users should perform an explicit <code>flush()</code>
					on any open output streams to the file prior to invoking this method to ensure 
					accurate results.
					<P></P>
					<DD>
						<DL>
						</DL>
						<DD>
							<DL>
								<DT><B>Returns:</B><DD>The size in bytes of the selected file, or -1 if the file does 
										not exist or is not accessible. <DT><B>Throws:</B>
											<DD>
												<CODE>java.io.IOException</CODE> - if the method is invoked on a directory.
												<DD>
													<CODE>java.lang.SecurityException</CODE> - if the security of the application 
													does not have read access for the file.
													<DD>
														<CODE><A HREF="../../../../javax/microedition/io/file/IllegalModeException.html">IllegalModeException</A></CODE>
														- if the application does have read access to the file but has opened the 
														connection in <code>Connector.WRITE</code> mode.
														<DD>
															<CODE><A HREF="../../../../javax/microedition/io/file/ConnectionClosedException.html">ConnectionClosedException</A></CODE>
															- if the connection is closed.</DD></DL>
						</DD>
			</DL>
			<HR>
			<A NAME="canRead()"><!-- --></A><H3>
				canRead</H3>
			<PRE>
public boolean <B>canRead</B>()</PRE>
			<DL>
				<DD>
					Checks if the file or directory is readable. This method checks the attributes 
					associated with a file or directory by the underlying file system. Some file 
					systems may not support associating a read attribute with a file, in which case 
					this method returns true.
					<P></P>
					<DD>
						<DL>
						</DL>
						<DD>
							<DL>
								<DT><B>Returns:</B><DD>true if the connection's target exists, is accessible, and is 
										readable, otherwise false. <DT><B>Throws:</B>
											<DD>
												<CODE>java.lang.SecurityException</CODE> - if the security of the application 
												does not have read access for the connection's target.
												<DD>
													<CODE><A HREF="../../../../javax/microedition/io/file/IllegalModeException.html">IllegalModeException</A></CODE>
													- if the application does have read access to the connection's target but has 
													opened the connection in <code>Connector.WRITE</code> mode.
													<DD>
														<CODE><A HREF="../../../../javax/microedition/io/file/ConnectionClosedException.html">ConnectionClosedException</A></CODE>
														- if the connection is closed.<DT><B>See Also:</B><DD><A HREF="../../../../javax/microedition/io/file/FileConnection.html#setReadable(boolean)"><CODE>setReadable(boolean)</CODE></A></DD></DL>
						</DD>
			</DL>
			<HR>
			<A NAME="canWrite()"><!-- --></A><H3>
				canWrite</H3>
			<PRE>
public boolean <B>canWrite</B>()</PRE>
			<DL>
				<DD>
					Checks if the file or directory is writable. This method checks the attributes 
					associated with a file or directory by the underlying file system. Some file 
					systems may not support associating a write attribute with a file, in which 
					case this method returns true.
					<P></P>
					<DD>
						<DL>
						</DL>
						<DD>
							<DL>
								<DT><B>Returns:</B><DD>true if the connection's target exists, is accessible, and is 
										writable, otherwise false. <DT><B>Throws:</B>
											<DD>
												<CODE>java.lang.SecurityException</CODE> - if the security of the application 
												does not have read access for the connection's target.
												<DD>
													<CODE><A HREF="../../../../javax/microedition/io/file/IllegalModeException.html">IllegalModeException</A></CODE>
													- if the application does have read access to the connection's target but has 
													opened the connection in <code>Connector.WRITE</code> mode.
													<DD>
														<CODE><A HREF="../../../../javax/microedition/io/file/ConnectionClosedException.html">ConnectionClosedException</A></CODE>
														- if the connection is closed.<DT><B>See Also:</B><DD><A HREF="../../../../javax/microedition/io/file/FileConnection.html#setWritable(boolean)"><CODE>setWritable(boolean)</CODE></A></DD></DL>
						</DD>
			</DL>
			<HR>
			<A NAME="isHidden()"><!-- --></A><H3>
				isHidden</H3>
			<PRE>
public boolean <B>isHidden</B>()</PRE>
			<DL>
				<DD>
					Checks if the file is hidden. The exact definition of hidden is 
					system-dependent. For example, on UNIX systems a file is considered to be 
					hidden if its name begins with a period character ('.'). On Win32 and FAT file 
					systems, a file is considered to be hidden if it has been marked as such in the 
					file's attributes. If hidden files are not supported on the referenced file 
					system, this method always returns false.
					<P></P>
					<DD>
						<DL>
						</DL>
						<DD>
							<DL>
								<DT><B>Returns:</B><DD>true if the file exists, is accessible, and is hidden, otherwise 
										false. <DT><B>Throws:</B>
											<DD>
												<CODE><A HREF="../../../../javax/microedition/io/file/ConnectionClosedException.html">ConnectionClosedException</A></CODE>
												- if the connection is closed.
												<DD>
													<CODE>java.lang.SecurityException</CODE> - if the security of the application 
													does not have read access for the connection's target.
													<DD>
														<CODE><A HREF="../../../../javax/microedition/io/file/IllegalModeException.html">IllegalModeException</A></CODE>
														- if the application does have read access to the connection's target but has 
														opened the connection in <code>Connector.WRITE</code> mode.<DT><B>See Also:</B><DD><A HREF="../../../../javax/microedition/io/file/FileConnection.html#setHidden(boolean)"><CODE>setHidden(boolean)</CODE></A></DD></DL>
						</DD>
			</DL>
			<HR>
			<A NAME="setReadable(boolean)"><!-- --></A><H3>
				setReadable</H3>
			<PRE>
public void <B>setReadable</B>(boolean&nbsp;readable)
                 throws java.io.IOException</PRE>
			<DL>
				<DD>
					Sets the file or directory readable attribute to the indicated value. The 
					readable attribute for the file on the actual file system is set immediately 
					upon invocation of this method. If the file system doesn't support a settable 
					read attribute, this method is ignored and <code>canRead()</code> always 
					returns true.
					<P></P>
					<DD>
						<DL>
						</DL>
						<DD>
							<DL>
								<DT><B>Parameters:</B><DD><CODE>readable</CODE> - The new state of the readable flag of 
										the selected file. <DT><B>Throws:</B>
											<DD>
												<CODE>java.io.IOException</CODE> - of the connection's target does not exist or 
												is not accessible.
												<DD>
													<CODE><A HREF="../../../../javax/microedition/io/file/ConnectionClosedException.html">ConnectionClosedException</A></CODE>
													- if the connection is closed.
													<DD>
														<CODE>java.lang.SecurityException</CODE> - if the security of the application 
														does not have write access to the connection's target.
														<DD>
															<CODE><A HREF="../../../../javax/microedition/io/file/IllegalModeException.html">IllegalModeException</A></CODE>
															- if the application does have write access to the connection's target but has 
															opened the connection in <code>Connector.READ</code> mode.<DT><B>See Also:</B><DD><A HREF="../../../../javax/microedition/io/file/FileConnection.html#canRead()"><CODE>canRead()</CODE></A></DD></DL>
						</DD>
			</DL>
			<HR>
			<A NAME="setWritable(boolean)"><!-- --></A><H3>
				setWritable</H3>
			<PRE>