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Java(TM) 2 Platform, Standard Edition, v1.2.2 API Specification: Class FileOutputStream - JDK 5 Documentation v1.2.2, Java 2 SDK 英文文档

JavaTM 2 Platform
Standard Edition

java.io
Class FileOutputStream

java.lang.Object
  |
  +--java.io.OutputStream
        |
        +--java.io.FileOutputStream

public class FileOutputStream
extends OutputStream

A file output stream is an output stream for writing data to a File or to a FileDescriptor. What files are available or may be created depends on the host environment.

Since:
JDK1.0
See Also:
File, FileDescriptor, FileInputStream

Constructor Summary
FileOutputStream(File file)
          Creates a file output stream to write to the file represented by the specified File object.
FileOutputStream(FileDescriptor fdObj)
          Creates an output file stream to write to the specified file descriptor, which represents an existing connection to an actual file in the file system.
FileOutputStream(String name)
          Creates an output file stream to write to the file with the specified name.
FileOutputStream(String name, boolean append)
          Creates an output file stream to write to the file with the specified name.
 
Method Summary
 void close()
          Closes this file output stream and releases any system resources associated with this stream.
protected  void finalize()
          Cleans up the connection to the file, and ensures that the close method of this file output stream is called when there are no more references to this stream.
 FileDescriptor getFD()
          Returns the file descriptor associated with this stream.
 void write(byte[] b)
          Writes b.length bytes from the specified byte array to this file output stream.
 void write(byte[] b, int off, int len)
          Writes len bytes from the specified byte array starting at offset off to this file output stream.
 void write(int b)
          Writes the specified byte to this file output stream.
 
Methods inherited from class java.io.OutputStream
flush
 
Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

FileOutputStream

public FileOutputStream(String name)
                 throws FileNotFoundException
Creates an output file stream to write to the file with the specified name. A new FileDescriptor object is created to represent this file connection.

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

If the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason then a FileNotFoundException is thrown.

Parameters:
name - the system-dependent filename
Throws:
FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason
SecurityException - if a security manager exists and its checkWrite method denies write access to the file.
See Also:
SecurityManager.checkWrite(java.lang.String)

FileOutputStream

public FileOutputStream(String name,
                        boolean append)
                 throws FileNotFoundException
Creates an output file stream to write to the file with the specified name. If the second argument is true, then bytes will be written to the end of the file rather than the beginning. A new FileDescriptor object is created to represent this file connection.

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

If the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason then a FileNotFoundException is thrown.

Parameters:
name - the system-dependent file name
append - if true, then bytes will be written to the end of the file rather than the beginning
Throws:
FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason.
SecurityException - if a security manager exists and its checkWrite method denies write access to the file.
Since:
JDK1.1
See Also:
SecurityManager.checkWrite(java.lang.String)

FileOutputStream

public FileOutputStream(File file)
                 throws IOException
Creates a file output stream to write to the file represented by the specified File object. A new FileDescriptor object is created to represent this file connection.

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

If the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason then a FileNotFoundException is thrown.

Parameters:
file - the file to be opened for writing.
Throws:
FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason
SecurityException - if a security manager exists and its checkWrite method denies write access to the file.
See Also:
File.getPath(), SecurityException, SecurityManager.checkWrite(java.lang.String)

FileOutputStream

public FileOutputStream(FileDescriptor fdObj)
Creates an output file stream to write to the specified file descriptor, which represents an existing connection to an actual file in the file system.

First, if there is a security manager, its checkWrite method is called with the file descriptor fdObj argument as its argument.

Parameters:
fdObj - the file descriptor to be opened for writing.
Throws:
SecurityException - if a security manager exists and its checkWrite method denies write access to the file descriptor.
See Also:
SecurityManager.checkWrite(java.io.FileDescriptor)
Method Detail

write

public void write(int b)
           throws IOException
Writes the specified byte to this file output stream. Implements the write method of OutputStream.
Overrides:
write in class OutputStream
Parameters:
b - the byte to be written.
Throws:
IOException - if an I/O error occurs.

write

public void write(byte[] b)
           throws IOException
Writes b.length bytes from the specified byte array to this file output stream.
Overrides:
write in class OutputStream
Parameters:
b - the data.
Throws:
IOException - if an I/O error occurs.

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException
Writes len bytes from the specified byte array starting at offset off to this file output stream.
Overrides:
write in class OutputStream
Parameters:
b - the data.
off - the start offset in the data.
len - the number of bytes to write.
Throws:
IOException - if an I/O error occurs.

close

public void close()
           throws IOException
Closes this file output stream and releases any system resources associated with this stream. This file output stream may no longer be used for writing bytes.
Overrides:
close in class OutputStream
Throws:
IOException - if an I/O error occurs.

getFD

public final FileDescriptor getFD()
                           throws IOException
Returns the file descriptor associated with this stream.
Returns:
the FileDescriptor object that represents the connection to the file in the file system being used by this FileOutputStream object.
Throws:
IOException - if an I/O error occurs.
See Also:
FileDescriptor

finalize

protected void finalize()
                 throws IOException
Cleans up the connection to the file, and ensures that the close method of this file output stream is called when there are no more references to this stream.
Overrides:
finalize in class Object
Throws:
IOException - if an I/O error occurs.
See Also:
FileInputStream.close()

JavaTM 2 Platform
Standard Edition

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