What is the difference between the file and randomaccessfile classes

But File objects are also not the File. They only contain the path to the file and are pointing onto it.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Asked 3 years, 2 months ago. Active 3 years, 2 months ago. Viewed 2k times. My Questions are 1 Does the array contains actual files or the reference to the files? Improve this question. You might want to read up on both classes. Additionally RandomAccessFile doesn't even have methods like exists so of course you need to use File.

Add a comment. Active Oldest Votes. Improve this answer. Kayaman Kayaman So no, they only point to the files. Donatic Donatic 11 11 bronze badges. Abdullah Hassan Abdullah Hassan 1 1 silver badge 7 7 bronze badges.

Sign up or log in Sign up using Google. Sign up using Facebook. If this file has an associated channel then the channel is closed as well.

This method reads a single byte from the file, starting at the current file pointer. A value of 0 represents false. Any other value represents true.

This method blocks until the byte is read, the end of the stream is detected, or an exception is thrown. Specified by: readBoolean in interface DataInput Returns: the boolean value read. Throws: EOFException - if this file has reached the end. This method reads a byte from the file, starting from the current file pointer. Specified by: readByte in interface DataInput Returns: the next byte of this file as a signed eight-bit byte. This method reads a byte from this file, starting at the current file pointer, and returns that byte.

Specified by: readUnsignedByte in interface DataInput Returns: the next byte of this file, interpreted as an unsigned eight-bit number. The method reads two bytes from this file, starting at the current file pointer. Specified by: readShort in interface DataInput Returns: the next two bytes of this file, interpreted as a signed bit number. Throws: EOFException - if this file reaches the end before reading two bytes. This method reads two bytes from the file, starting at the current file pointer.

Specified by: readUnsignedShort in interface DataInput Returns: the next two bytes of this file, interpreted as an unsigned bit integer. Specified by: readChar in interface DataInput Returns: the next two bytes of this file, interpreted as a char. This method reads 4 bytes from the file, starting at the current file pointer. Specified by: readInt in interface DataInput Returns: the next four bytes of this file, interpreted as an int.

Throws: EOFException - if this file reaches the end before reading four bytes. This method reads eight bytes from the file, starting at the current file pointer. Specified by: readLong in interface DataInput Returns: the next eight bytes of this file, interpreted as a long. Throws: EOFException - if this file reaches the end before reading eight bytes.

This method reads an int value, starting at the current file pointer, as if by the readInt method and then converts that int to a float using the intBitsToFloat method in class Float.

This method blocks until the four bytes are read, the end of the stream is detected, or an exception is thrown. Specified by: readFloat in interface DataInput Returns: the next four bytes of this file, interpreted as a float. See Also: readInt , Float. This method reads a long value, starting at the current file pointer, as if by the readLong method and then converts that long to a double using the longBitsToDouble method in class Double. This method blocks until the eight bytes are read, the end of the stream is detected, or an exception is thrown.

Specified by: readDouble in interface DataInput Returns: the next eight bytes of this file, interpreted as a double. See Also: readLong , Double.

This method successively reads bytes from the file, starting at the current file pointer, until it reaches a line terminator or the end of the file. Each byte is converted into a character by taking the byte's value for the lower eight bits of the character and setting the high eight bits of the character to zero. This method does not, therefore, support the full Unicode character set. Line-terminating characters are discarded and are not included as part of the string returned.

This method blocks until a newline character is read, a carriage return and the byte following it are read to see if it is a newline , the end of the file is reached, or an exception is thrown.

Specified by: readLine in interface DataInput Returns: the next line of text from this file, or null if end of file is encountered before even one byte is read. The string has been encoded using a modified UTF-8 format. The first two bytes are read, starting from the current file pointer, as if by readUnsignedShort. This value gives the number of following bytes that are in the encoded string, not the length of the resulting string.

The following bytes are then interpreted as bytes encoding characters in the modified UTF-8 format and are converted into characters. This method blocks until all the bytes are read, the end of the stream is detected, or an exception is thrown.

The value true is written out as the value byte 1 ; the value false is written out as the value byte 0. The write starts at the current position of the file pointer. Specified by: writeBoolean in interface DataOutput Parameters: v - a boolean value to be written.

Specified by: writeByte in interface DataOutput Parameters: v - a byte value to be written. Specified by: writeShort in interface DataOutput Parameters: v - a short to be written. Specified by: writeChar in interface DataOutput Parameters: v - a char value to be written. Specified by: writeInt in interface DataOutput Parameters: v - an int to be written. Specified by: writeLong in interface DataOutput Parameters: v - a long to be written.

Specified by: writeFloat in interface DataOutput Parameters: v - a float value to be written. See Also: Float. Specified by: writeDouble in interface DataOutput Parameters: v - a double value to be written. See Also: Double. Each character in the string is written out, in sequence, by discarding its high eight bits.

Specified by: writeBytes in interface DataOutput Parameters: s - a string of bytes to be written. Each character is written to the data output stream as if by the writeChar method. First, two bytes are written to the file, starting at the current file pointer, as if by the writeShort method giving the number of bytes to follow. This value is the number of bytes actually written out, not the length of the string.

Following the length, each character of the string is output, in sequence, using the modified UTF-8 encoding for each character. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy. Object java. A random access file behaves like a large array of bytes stored in the file system. There is a kind of cursor, or index into the implied array, called the file pointer ; input operations read bytes starting at the file pointer and advance the file pointer past the bytes read.

Output operations that write past the current end of the implied array cause the array to be extended. The file pointer can be read by the getFilePointer method and set by the seek method.

Constructor Summary Constructors Constructor and Description RandomAccessFile File file, String mode Creates a random access file stream to read from, and optionally to write to, the file specified by the File argument. Creates a random access file stream to read from, and optionally to write to, a file with the specified name. Closes this random access file stream and releases any system resources associated with the stream.

Returns the unique FileChannel object associated with this file. Reads up to b. Reads up to len bytes of data from this file into an array of bytes. Reads b. Reads exactly len bytes from this file into the byte array, starting at the current file pointer. Sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs. Attempts to skip over n bytes of input discarding the skipped bytes. Writes b.

Writes len bytes from the specified byte array starting at offset off to this file. 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. 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.

Writes a string to the file using modified UTF-8 encoding in a machine-independent manner. Creates a random access file stream to read from, and optionally to write to, the file specified by the File argument. The permitted values and their meanings are: Value Meaning "r" Open for reading only. Invoking any of the write methods of the resulting object will cause an IOException to be thrown.

If the file does not already exist then an attempt will be made to create it. If the file resides on a local storage device then when an invocation of a method of this class returns it is guaranteed that all changes made to the file by that invocation will have been written to that device.