FileInputStream JDK 1.6)

Constructors

public FileInputStream (File file) throws FileNotFoundException

Creates a FileInputStream by opening a connection to an actual file, the file named by the File object file in the file system.

Creates a FileInputStream by opening a connection to an actual file, the file named by the File object file in the file system. A new FileDescriptor object is created to represent this file connection.

First, if there is a security manager, its checkRead method is called with the path represented by the file argument as its argument.

If the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading then a FileNotFoundException is thrown.
Parameters:
- file - the file to be opened for reading.
Throws:
- FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
- SecurityException - if a security manager exists and its checkRead method denies read access to the file.
See Also: File.getPath(), SecurityManager.checkRead(java.lang.String),

public FileInputStream (FileDescriptor fdObj)

Creates a FileInputStream by using the file descriptor fdObj, which represents an existing connection to an actual file in the file system.

If there is a security manager, its checkRead method is called with the file descriptor fdObj as its argument to see if it's ok to read the file descriptor. If read access is denied to the file descriptor a SecurityException is thrown.

If fdObj is null then a NullPointerException is thrown.
Parameters:
- fdObj - the file descriptor to be opened for reading.
Throws:
- SecurityException - if a security manager exists and its checkRead method denies read access to the file descriptor.
See Also: SecurityManager.checkRead(java.io.FileDescriptor),

public FileInputStream (String name) throws FileNotFoundException

Creates a FileInputStream by opening a connection to an actual file, the file named by the path name name in the file system.

Creates a FileInputStream by opening a connection to an actual file, the file named by the path name name in the file system. A new FileDescriptor object is created to represent this file connection.

First, if there is a security manager, its checkRead method is called with the name argument as its argument.

If the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading then a FileNotFoundException is thrown.
Parameters:
- name - the system-dependent file name.
Throws:
- FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
- SecurityException - if a security manager exists and its checkRead method denies read access to the file.
See Also: SecurityManager.checkRead(java.lang.String),

Methods

Hide/Show inherited methods

publicnative int available () throws IOException [Overrides InputStream]

Returns an estimate of the number of remaining bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.

public void close () throws IOException [Overrides InputStream]

Closes this file input stream and releases any system resources associated with the stream.

protected void finalize () throws IOException

Ensures that the close method of this file input stream is called when there are no more references to it.

Ensures that the close method of this file input stream is
called when there are no more references to it.
Throws:
- IOException - if an I/O error occurs.
See Also: FileInputStream.close(),

public FileChannel getChannel ()

Returns the unique FileChannel object associated with this file input stream.

publicfinal FileDescriptor getFD () throws IOException

Returns the FileDescriptor object that represents the connection to the actual file in the file system being used by this FileInputStream.

Returns the FileDescriptor
object that represents the connection to
the actual file in the file system being
used by this FileInputStream.
Returns: the file descriptor object associated with this stream.
Throws:
- IOException - if an I/O error occurs.
See Also: FileDescriptor,

publicsynchronized void mark (int readlimit) [Inherited From InputStream]

Marks the current position in this input stream.

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

The readlimit arguments tells this input stream to allow that many bytes to be read before the mark position gets invalidated.

The general contract of mark is that, if the method markSupported returns true, the stream somehow remembers all the bytes read after the call to mark and stands ready to supply those same bytes again if and whenever the method reset is called. However, the stream is not required to remember any data at all if more than readlimit bytes are read from the stream before reset is called.

Marking a closed stream should not have any effect on the stream.

The mark method of InputStream does nothing.
Parameters:
- readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.
See Also: InputStream.reset(),

public boolean markSupported () [Inherited From InputStream]

Tests if this input stream supports the mark and reset methods.

Tests if this input stream supports the mark and
reset methods. Whether or not mark and
reset are supported is an invariant property of a
particular input stream instance. The markSupported method
of InputStream returns false.
Returns: true if this stream instance supports the mark and reset methods; false otherwise.
See Also: InputStream.mark(int), InputStream.reset(),

publicnative int read () throws IOException [Specified in InputStream]

Reads a byte of data from this input stream.

Reads a byte of data from this input stream. This method blocks
if no input is yet available.
Returns: the next byte of data, or -1 if the end of the file is reached.
Throws:
- IOException - if an I/O error occurs.

public int read (byte[] b) throws IOException [Overrides InputStream]

Reads up to b.length bytes of data from this input stream into an array of bytes.

Reads up to b.length bytes of data from this input
stream into an array of bytes. This method blocks until some input
is available.
Returns: the total number of bytes read into the buffer, or -1 if there is no more data because the end of the file has been reached.
Parameters:
- b - the buffer into which the data is read.
Throws:
- IOException - if an I/O error occurs.

public int read (byte[] b, int off, int len) throws IOException [Overrides InputStream]

Reads up to len bytes of data from this input stream into an array of bytes.

Reads up to len bytes of data from this input stream
into an array of bytes. If len is not zero, the method
blocks until some input is available; otherwise, no
bytes are read and 0 is returned.
Returns: the total number of bytes read into the buffer, or -1 if there is no more data because the end of the file has been reached.
Parameters:
- b - the buffer into which the data is read.
- off - the start offset in the destination array b
- len - the maximum number of bytes read.
Throws:
- NullPointerException - If b is null.
- IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off
- IOException - if an I/O error occurs.

publicsynchronized void reset () throws IOException [Inherited From InputStream]

Repositions this stream to the position at the time the mark method was last called on this input stream.

The general contract of reset is:

If the method markSupported returns true, then:
- If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException might be thrown.
- If such an IOException is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset.
If the method markSupported returns false, then:
- The call to reset may throw an IOException.
- If an IOException is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read method depend on the particular type of the input stream.

The method reset for class InputStream does nothing except throw an IOException.
Throws:
- IOException - if this stream has not been marked or if the mark has been invalidated.
See Also: InputStream.mark(int), IOException,

publicnative long skip (long n) throws IOException [Overrides InputStream]

Skips over and discards n bytes of data from the input stream.

The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. If n is negative, an IOException is thrown, even though the skip method of the InputStream superclass does nothing in this case. The actual number of bytes skipped is returned.

This method may skip more bytes than are remaining in the backing file. This produces no exception and the number of bytes skipped may include some number of bytes that were beyond the EOF of the backing file. Attempting to read from the stream after skipping past the end will result in -1 indicating the end of the file.
Returns: the actual number of bytes skipped.
Parameters:
- n - the number of bytes to be skipped.
Throws:
- IOException - if n is negative, if the stream does not support seek, or if an I/O error occurs.