java.lang.Object
java.io.RandomAccessFile
- All Implemented Interfaces:
- Closeable, DataInput, DataOutput
- See Also:
- Top Examples, Source Code
public void close()
throws IOException- See Also:
- Closeable
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
[893]_
By Anonymous on 2004/12/21 14:46:03 Rate
import java.io.*;
public class foo {
public static void main ( String [ ] args ) throws IOException {
RandomAccessFile raf = new RandomAccessFile ( "foo.txt", "rw" ) ;
try {
Writer out = new OutputStreamWriter ( new FileOutputStream ( raf.getFD ( ) ) , "UTF-8" ) ;
out.write ( "Hello World!!" ) ;
out.flush ( ) ; //flush the stream before seeking to a new position
raf.seek ( 6 ) ; // Just before the 'W'
out.write ( "Java" ) ; //overwites "World" with "Java"
out.flush ( ) ;
}
finally {
raf.close ( ) ;
}
}
}
[1196]_
By Chris Johnson on 2005/02/02 18:50:25 Rate
For the example already given.. "Java" would overwrite "Worl" not "World".[1695]java file access
By mbiis { at } fsmail { dot } net on 2006/01/08 18:59:33 Rate
import java.io.*;
import java.util.*;
public class database
{
String [ ] [ ] contact;
int position = 0;
public database ( int noOfContact )
{
contact = new String [ noOfContact ] [ noOfContact ] ;
}
public void setDetails ( String name, String tel, String exten )
{
//Using the args place the data into
//to array with given current position.
//Increment the position by one
}
public void setName ( String name, int pos )
{
//set the name of entry with a given position
}
public void setTelepehone ( String tel, int pos )
{
//set the telephone number of an entry with given position
}
public void setExtension ( String exten, int pos )
{
//set extenstion number of an entry with given position
}
public void setNumbers ( String num, int pos )
{
//set addition number for this entry
//with given position
}
public String getFullName ( int pos )
{
//return the full name of the entry with given position
return "";
}
public String getTelephone ( int pos )
{
//return telephone number of entry with given position
return "";
}
public String getExtenstion ( int pos )
{
//return extension number of entry with given position
return "";
}
public String [ ] getDetails ( int pos )
{
//create an array of position depending on the entry information
//data type of string
//store information about the entry
//in each array with a given position
//return the array
return null;
}
public int searchByName ( String s )
{
//this method returns the position of the array
//where the contact is being held
return 0;
}
public int searchByNumber ( String num )
{
//returns the position of this contact with given
//number
return 0;
}
public int searchByEx ( String ex )
{
//returns the position of this contact with given
//extenstion number
return 0;
}
public String [ ] [ ] getAllContacts ( )
{
return contact;
}
public int getPos ( int tel )
{
//get the position of contact with a given telephone number
//remember to convert the int to string
//then query the arrays
return 0;
}
public boolean save ( String file )
{
boolean b = false;
//Save the 2d array into a flat file
//with given file name
//return b as true if save is successfull
return b;
}
public boolean load ( String file )
{
boolean b = false;
//load each contact and save into
//3d array with given file name to load from
//providing feedback to illistrate that the file has been loaded successfully
return b;
}
} [1796]copy a part of a file to another binary file
By ab on 2006/07/31 09:38:06 Rate
// copy bytes [ beginn,end ) from input file to output file:
RandomAccessFile in = new RandomAccessFile ( fname_in, "r" ) ;
RandomAccessFile out= new RandomAccessFile ( fname_out, "rw" ) ;
int len = ( int ) in.length ( ) ; // not used
int begin=...;
int end=...;
int buf_sz=1024*1024;
byte buf [ ] = new byte [ buf_sz ] ;
while ( begin < end ) {
int cp_len=end-begin;
if ( cp_len > buf_sz ) cp_len=buf_sz;
in.seek ( begin ) ;
in.readFully ( buf,0,cp_len ) ; // read cp_len bytes
out.write ( buf,0,cp_len ) ;
begin+=cp_len;
}
in.close ( ) ;
out.close ( ) ;
[1800]read some bytes from input file and append to output file
By Anonymous on 2006/08/05 09:29:48 Rate
// copy bytes [ beginn,end ) from input file to output file:
// parameters: infile outfile start end
public static void main ( String [ ] args ) throws IOException, NumberFormatException {
String infile=args [ 0 ] ;
String outfile=args [ 1 ] ;
int begin=Integer.parseInt ( args [ 2 ] ) ;
int end=Integer.parseInt ( args [ 3 ] ) ;
RandomAccessFile in = new RandomAccessFile ( infile, "r" ) ;
RandomAccessFile out= new RandomAccessFile ( outfile, "rw" ) ;
int len = ( int ) in.length ( ) ; // get length of input file
int len2= ( int ) out.length ( ) ; // get length of output file
out.seek ( len2 ) ; // goto end of output file
int buf_sz=1024*1024;
byte buf [ ] = new byte [ buf_sz ] ;
while ( begin < end ) {
int cp_len=end-begin;
if ( cp_len > buf_sz ) cp_len=buf_sz;
in.seek ( begin ) ;
in.readFully ( buf,0,cp_len ) ; // read cp_len bytes into buffer
out.write ( buf,0,cp_len ) ; // write bytes
begin+=cp_len;
}
in.close ( ) ;
out.close ( ) ;
}
public final FileChannel getChannel()
- See Also:
getFilePointer,
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final FileDescriptor getFD()
throws IOException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public long getFilePointer()
throws IOException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public long length()
throws IOException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public RandomAccessFile(File file,
String mode)
throws FileNotFoundException- See Also:
FileDescriptor
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public RandomAccessFile(String name,
String mode)
throws FileNotFoundException- See Also:
SecurityManager.checkWrite(java.lang.String), SecurityManager.checkRead(java.lang.String), SecurityException, IllegalArgumentException, FileDescriptor
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
[419]_
By Anonymous on 2004/01/20 23:18:08 Rate
RandomAccessFile f = new RandomAccessFile ( "A:\\conexion.txt", "r" ) ;
[772]Append to a file
By JavaJeffG on 2004/09/01 06:52:13 Rate
// Opens file in read/write mode ( "rw" ) .
// Appends requests at end of file.
RandomAccessFile raf = new RandomAccessFile ( "OutputFile.txt", "rw" ) ;
raf.seek ( raf.length ( ) ) ; // Jump to EOF.
...
raf.close ( ) ;
public int read()
throws IOException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public int read(byte[] b)
throws IOException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public int read(byte[] b,
int off,
int len)
throws IOException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final boolean readBoolean()
throws IOException- See Also:
- EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final byte readByte()
throws IOException- See Also:
- EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final char readChar()
throws IOException- See Also:
- EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final double readDouble()
throws IOException- See Also:
Double.longBitsToDouble(long), readLong(), EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final float readFloat()
throws IOException- See Also:
Float.intBitsToFloat(int), readInt(), EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void readFully(byte[] b)
throws IOException- See Also:
- EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void readFully(byte[] b,
int off,
int len)
throws IOException- See Also:
- EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int readInt()
throws IOException- See Also:
- EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final String readLine()
throws IOException- See Also:
- DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final long readLong()
throws IOException- See Also:
- EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final short readShort()
throws IOException- See Also:
- EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int readUnsignedByte()
throws IOException- See Also:
- EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int readUnsignedShort()
throws IOException- See Also:
- EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final String readUTF()
throws IOException- See Also:
readUnsignedShort(), UTFDataFormatException, EOFException, DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public void seek(long pos)
throws IOException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public void setLength(long newLength)
throws IOException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
[1345]Skip some part of fixed bytes from the ending portion of the file
By Anonymous on 2005/03/14 01:48:56 Rate
RandomAccessFile raf = new RandomAccessFile ( "RandFile.txt", "rw" ) ;
//getting the file length
long length = raf.length ( ) ;
System.out.println ( "File Length="+raf.length ( ) ) ;
//reducing the length by 8.This is useful when you want to
//skip some part of fixed bytes from the ending portion of the file
//here it is 44
raf.setLength ( length - 44 ) ;
System.out.println ( "File Length="+raf.length ( ) ) ;
public int skipBytes(int n)
throws IOException- See Also:
- DataInput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public void write(byte[] b)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public void write(byte[] b,
int off,
int len)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public void write(int b)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeBoolean(boolean v)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeByte(int v)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeBytes(String s)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeChar(int v)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeChars(String s)
throws IOException- See Also:
writeChar(int), DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeDouble(double v)
throws IOException- See Also:
Double.doubleToLongBits(double), DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeFloat(float v)
throws IOException- See Also:
Float.floatToIntBits(float), DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeInt(int v)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeLong(long v)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeShort(int v)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void writeUTF(String str)
throws IOException- See Also:
- DataOutput
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
Java API By Example, From Geeks To Geeks.