Java Fundamentals Hardening IO Stream Note 63: Random Access Stream Randomaccessfile

1. Random Access Stream Randomaccessfile

The Randomaccessfile class does not belong to a stream and is a subclass of the object class. But it incorporates the functions of InputStream and OutputStream. Supports read and write to random access files.

Randomaccessfile Method of Construction:

Construction Method Summary
RandomAccessFile(File file, String mode) Creates a random-access file stream from which to read and write (optionally), which is specified by the File parameter.
RandomAccessFile(String name, String mode) Creates a random-access file stream from which to read and write (optionally) a file with the specified name.

2. code example:

1  Packagecn.itcast_05;2 3 Importjava.io.IOException;4 ImportJava.io.RandomAccessFile;5 6 /*7 * Public randomaccessfile (String name,string mode): The first parameter is the file path, and the second parameter is the mode of the action file. 8 * There are four modes, our most commonly used is called "RW", this means that I can write data, can also read data9  */Ten  Public classRandomaccessfiledemo { One      Public Static voidMain (string[] args)throwsIOException { A         //write (); - read (); -     } the  -     Private Static voidRead ()throwsIOException { -         //Create a random-access stream object -Randomaccessfile RAF =NewRandomaccessfile ("Raf.txt", "RW"); +  -         inti =raf.readint (); + System.out.println (i); A         //The file pointer can be read by the Getfilepointer method and set through the Seek method.  atSYSTEM.OUT.PRINTLN ("The pointer position of the current file is:" +Raf.getfilepointer ()); -  -         CharCH =Raf.readchar (); - System.out.println (CH); -SYSTEM.OUT.PRINTLN ("The pointer position of the current file is:" +Raf.getfilepointer ()); -  inString s =Raf.readutf (); - System.out.println (s); toSYSTEM.OUT.PRINTLN ("The pointer position of the current file is:" +Raf.getfilepointer ()); +  -         //I don't want to start over, I'm going to read a, what do I do? the function of random access can be achieved by the Seek location method  theRaf.seek (4); *CH =Raf.readchar (); $ System.out.println (CH);Panax Notoginseng     } -  the     Private Static voidWrite ()throwsIOException { +         //Create a random-access stream object ARandomaccessfile RAF =NewRandomaccessfile ("Raf.txt", "RW"); the  +         //How to play it? -Raf.writeint (100); $Raf.writechar (' a '); $RAF.WRITEUTF ("China")); -  - raf.close (); the     } -}

Run the effect as follows:

Java Fundamentals Hardening IO Stream Note 63: Random Access Stream Randomaccessfile