Java.io.RandomAccessFile Class

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Introduction

The Java.io.RandomAccessFile class file behaves like a large array of bytes stored in the file system.Instances of this class support both reading and writing to a random access file.

Class declaration

Following is the declaration for Java.io.RandomAccessFile class −

public class RandomAccessFile
   extends Object
      implements DataOutput, DataInput, Closeable

Class constructors

Sr.No. Constructor & Description
1

RandomAccessFile(File file, String mode)

This creates a random access file stream to read from, and optionally to write to, the file specified by the File argument.
2

RandomAccessFile(File file, String mode)

This creates a random access file stream to read from, and optionally to write to, a file with the specified name.

Class methods

Sr.No. Method & Description
1 void close()

This method Closes this random access file stream and releases any system resources associated with the stream.
2 FileChannel getChannel()

This method returns the unique FileChannel object associated with this file.
3 FileDescriptor getFD()

This method returns the opaque file descriptor object associated with this stream.
4 long getFilePointer()

This method returns the current offset in this file.
5 long length()

This method returns the length of this file.
6 int read()

This method reads a byte of data from this file.
7 int read(byte[] b)

This method reads up to b.length bytes of data from this file into an array of bytes.
8 int read(byte[] b, int off, int len)

This method reads up to len bytes of data from this file into an array of bytes.
9 boolean readBoolean()

This method reads a boolean from this file.
10 byte readByte()

This method reads a signed eight-bit value from this file.
11 char readChar()

This method reads a character from this file.
12 double readDouble()

This method reads a double from this file.
13 float readFloat()

This method reads a float from this file.
14 void readFully(byte[] b)

This method reads b.length bytes from this file into the byte array, starting at the current file pointer.
15 void readFully(byte[] b, int off, int len)

This method reads exactly len bytes from this file into the byte array, starting at the current file pointer.
16 int readInt()

This method reads a signed 32-bit integer from this file.
17 String readLine()

This method reads the next line of text from this file.
18 long readLong()

This method reads a signed 64-bit integer from this file.
19 short readShort()

This method reads a signed 16-bit number from this file.
20 int readUnsignedByte()

This method reads an unsigned eight-bit number from this file.
21 int readUnsignedShort()

This method reads an unsigned 16-bit number from this file.
22 String readUTF()

This method reads in a string from this file.
23 void seek(long pos)

This method sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs.
24 void setLength(long newLength)

This method sets the length of this file.
25 int skipBytes(int n)

This method attempts to skip over n bytes of input discarding the skipped bytes.
26 void write(byte[] b)

This method writes b.length bytes from the specified byte array to this file, starting at the current file pointer.
27 void write(byte[] b, int off, int len)

This method writes len bytes from the specified byte array starting at offset off to this file.
28 void write(int b)

This method writes the specified byte to this file.
29 void writeBoolean(boolean v)

This method writes a boolean to the file as a one-byte value.
30 void writeByte(int v)

This method writes a byte to the file as a one-byte value.
31 void writeBytes(String s)

This method writes the string to the file as a sequence of bytes.
32 void writeChar(int v)

This method writes a char to the file as a two-byte value, high byte first.
33 void writeChars(String s)

This method writes a string to the file as a sequence of characters.
34 void writeDouble(double v)

This method converts the double argument to a long using the doubleToLongBits method in class Double, and then writes that long value to the file as an eight-byte quantity, high byte first.
35 void writeFloat(float v)

This method converts the float argument to an int using the floatToIntBits method in class Float, and then writes that int value to the file as a four-byte quantity, high byte first.
36 void writeInt(int v)

This method writes an int to the file as four bytes, high byte first.
37 void writeLong(long v)

This method writes a long to the file as eight bytes, high byte first.
38 void writeShort(int v)

This method writes a short to the file as two bytes, high byte first.
39 void writeUTF(String str)

This method writes a string to the file using modified UTF-8 encoding in a machine-independent manner.

Methods inherited

This class inherits methods from the following classes −

  • Java.io.Object
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