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§2.9 Class FileInputStream

public  class  java.io.FileInputStream
    extends  java.io.InputStream  (I-§2.13)
{
        // Constructors
    public FileInputStream(File  file);	§2.9.1
    public FileInputStream(FileDescriptor  fdObj);	§2.9.2
    public FileInputStream(String  name);	§2.9.3

        // Methods
    public int available();	§2.9.4
    public void close();	§2.9.5
    protected void finalize();	§2.9.6
    public final FileDescriptor getFD();	§2.9.7
    public int read();	§2.9.8
    public int read(byte  b[]);	§2.9.9
    public int read(byte  b[], int  off, int  len);	§2.9.10
    public long skip(long  n);	§2.9.11
}

A file input stream is an input stream for reading data from a File (I-§2.7) or from a FileDescriptor (I-§2.8).

FileInputStream

public FileInputStream(File  file)

throws FileNotFoundException

Creates an input file stream to read from the specified File object

Parameters:: file -the file to be opened for reading
Throws: FileNotFoundException (I-§2.28); If the file is not found.
Throws: SecurityException (I-§1.43); If a security manager exists, its checkRead method (I-§1.15.19) is called with the path name (I-§2.7.16) of this File argument to see if the application is allowed read access to the file. This may result in a security exception (I-§1.43).

FileInputStream

public FileInputStream(FileDescriptor  fdObj)

Creates an input file stream to read from the specified file descriptor

Parameters:: fdObj -the file descriptor to be opened for reading
Throws: SecurityException (I-§1.43); If a security manager exists, its checkRead method (I-§1.15.18) is called with the file descriptor to see if the application is allowed to read from the specified file descriptor. This may result in a security exception (I-§1.43).

FileInputStream

public FileInputStream(String  name)

throws FileNotFoundException

Creates an input file stream to read from a file with the specified name.

If a security manager exists, its checkRead method (I-§1.15.19) is called with the name argument t to see if the application is allowed read access to the file. This may result in a security exception (I-§1.43).

Parameters:: name -the system dependent file name
Throws: FileNotFoundException (I-§2.28); If the file is not found.
Throws: SecurityException (I-§1.43); If a security manager exists, its checkRead method (I-§1.15.19) is called with the name argument t to see if the application is allowed read access to the file. This may result in a security exception (I-§1.43).

available

public int available()

throws IOException

Returns:: the number of bytes that can be read from this file input stream without blocking.
Throws: IOException (I-§2.29); If an I/O error occurs.
Overrides:: available in class InputStream (I-§2.13.2).

close

public void close()

throws IOException

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

Throws: IOException (I-§2.29); If an I/O error occurs.
Overrides:: close in class InputStream (I-§2.13.3).

finalize

protected void finalize()

throws IOException

This finalize method ensures that the close method (I-§2.9.5) of this file input stream is called when there are no more references to it.

Throws: IOException (I-§2.29); If an I/O error occurs.
Overrides:: finalize in class Object (I-§1.12.4).

getFD

public final FileDescriptor getFD()

throws IOException

Returns:: the file descriptor object (I-§2.8) associated with this stream.
Throws: IOException (I-§2.29); If an I/O error occurs.

read

public int read()

throws IOException

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 (I-§2.29); If an I/O error occurs.
Overrides:: read in class InputStream (I-§2.13.6).

read

public int read(byte  b[])

throws IOException

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.

Parameters:: b -the buffer into which the data is read
Returns:: the total number of bytes read into the buffer, or -1 is there is no more data because the end of the file has been reached.
Throws: IOException (I-§2.29); If an I/O error occurs.
Overrides:: read in class InputStream (I-§2.13.7).

read

public int read(byte  b[], int  off, int  len)

throws IOException

Reads up to len bytes of data from this input stream into an array of bytes. This method blocks until some input is available.

Parameters:: b -the buffer into which the data is read; off -the start offset of the data; len -the maximum number of bytes read
Returns:: the total number of bytes read into the buffer, or -1 is there is no more data because the end of the file has been reached.
Throws: IOException (I-§2.29); If an I/O error occurs.
Overrides:: read in class InputStream (I-§2.13.8).

skip

public long skip(long  n)

throws IOException

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 zero. The actual number of bytes skipped is returned.

Parameters:: n -the number of bytes to be skipped
Returns:: the actual number of bytes skipped.
Throws: IOException (I-§2.29); If an I/O error occurs.
Overrides:: skip in class InputStream (I-§2.13.10).

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