The purpose of this class is to handle input and output operations on a random access file, which functions similarly to a sizable byte array. Within this file, there exists a cursor referred to as the file pointer, which dictates where read and write operations occur. When the end of the file is encountered before reading the intended number of bytes, an EOFException is raised. This exception belongs to the IOException category.
Constructor
| Constructor | Description |
|---|---|
| RandomAccessFile(File file,Stringmode) | Creates a random access file stream to read from, and optionally to write to, the file specified by the File argument. |
| RandomAccessFile(String name, String mode) | Creates a random access file stream to read from, and optionally to write to, a file with the specified name. |
Method
| Modifier and Type | Method | Method |
|---|---|---|
void |
close() | It closes this random access file stream and releases any system resources associated with the stream. |
| FileChannel | getChannel() | It returns the uniqueFileChannelobject associated with this file. |
int |
readInt() | It reads a signed 32-bit integer from this file. |
| String | readUTF() | It reads in a string from this file. |
void |
seek(long pos) | It sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs. |
void |
writeDouble(double v) | It 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. |
void |
writeFloat(float v) | It 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. |
void |
write(int b) | It writes the specified byte to this file. |
int |
read() | It reads a byte of data from this file. |
long |
length() | It returns the length of this file. |
void |
seek(long pos) | It sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs. |
Example
Example
import java.io.IOException;
import java.io.RandomAccessFile;
public class RandomAccessFileExample {
static final String FILEPATH ="myFile.TXT";
public static void main(String[] args) {
try {
System.out.println(new String(readFromFile(FILEPATH, 0, 18)));
writeToFile(FILEPATH, "I love my country and my people", 31);
} catch (IOException e) {
e.printStackTrace();
}
}
private static byte[] readFromFile(String filePath, int position, int size)
throws IOException {
RandomAccessFile file = new RandomAccessFile(filePath, "r");
file.seek(position);
byte[] bytes = new byte[size];
file.read(bytes);
file.close();
return bytes;
}
private static void writeToFile(String filePath, String data, int position)
throws IOException {
RandomAccessFile file = new RandomAccessFile(filePath, "rw");
file.seek(position);
file.write(data.getBytes());
file.close();
}
}
The file named myFile.TXT includes the following text: "This class is utilized for both reading from and writing to a random access file."
after running the program it will contains
This class is utilized for the purpose of reading and manipulating text data.
