Chapter 11
The java.io Package

FileReader

Name

FileReader

Synopsis

Class Name:

java.io.FileReader

Superclass:

java.io.InputStreamReader

Immediate Subclasses:

None

Interfaces Implemented:

None

Availability:

New as of JDK 1.1

The FileReader class represents a character stream that reads data from a file. It is a subclass of InputStreamReader that uses a default buffer size (8192 bytes) to read bytes from a file and the default character encoding scheme to convert the bytes to characters. If you need to specify the character encoding or the buffer size, wrap an InputStreamReader around a FileInputStream.

The file can be specified using a FileDescriptor, a File object, or a String that represents a pathname. All of the constructors can throw a SecurityException if the application does not have permission to read from the specified file.

FileReader provides a low-level interface for reading character data from a file. You should think about wrapping a FileReader with a BufferedReader to increase reading efficiency.

If you need to read binary data from a file, you should use a FileInputStream wrapped by a DataInputStream instead.

Class Summary

public class java.io.FileReader extends java.io.InputStreamReader {
  // Constructors
  public FileReader(String fileName);
  public FileReader(File file);
  public FileReader(FileDescriptor fd);
}

Constructors

FileInputStream

public FileReader(String fileName) throws FileNotFoundException

Parameters

fileName: A String that contains the pathname of the file to be accessed. The path must conform to the requirements of the native operating system.

Throws

FileNotFoundException

If the named file cannot be found.

SecurityException

If the application does not have permission to read the named file.

Description

This constructor creates a FileReader that gets its input from the file named by the specified String.

public FileReader(File file) throws FileNotFoundException

Parameters

file: The File to use as input.

Throws

FileNotFoundException

If the named file cannot be found.

SecurityException

If the application does not have permission to read the named file.

Description

This constructor creates a FileReader that gets its input from the file represented by the specified File.

public FileReader(FileDescriptor fdObj)

Parameters

fdObj: The FileDescriptor of the file to use as input.

Throws

SecurityException

If the application does not have permission to read the specified file.

NullPointerException

If FileDescriptor is null.

Description

This constructor creates a FileReader that gets its input from the file identified by the given FileDescriptor.

Inherited Methods

Method	Inherited From	Method	Inherited From
`clone()`	`Object`	`close()`	`InputStreamReader`
`equals(Object)`	`Object`	`finalize()`	`Object`
`getClass()`	`Object`	`getEncoding()`	`InputStreamReader`
`hashCode()`	`Object`	`mark(int)`	`Reader`
`markSupported()`	`Reader`	`notify()`	`Object`
`notifyAll()`	`Object`	`read()`	`InputStreamReader`
`read(char[])`	`Reader`	`read(char[], int, int)`	`InputStreamReader`
`ready()`	`InputStreamReader`	`reset()`	`Reader`
`skip(long)`	`Reader`	`toString()`	`Object`
`wait()`	`Object`	`wait(long)`	`Object`
`wait(long, int)`	`Object`