Some Classes Used for File I/O

Textfiles

Classes and Methods for Program Output to a Textfile

PrintWriter textOutFile = new PrintWriter("somefile.txt");
PrintWriter textOutFile = new PrintWriter(new FileOutputStream("somefile.txt"));
PrintWriter textOutFile = new PrintWriter(new FileOutputStream("somefile.txt", true));

textOutFile.print()
textOutFile.println()
textOutFile.printf()

textOutFile.close()

Classes and Methods for Program Input from a Textfile

Scanner textInFile = new Scanner(new File("somefile.txt"));

textInFile.nextInt()        textInFile.hasNextInt()
textInFile.nextDouble()     textInFile.hasNextDouble()
textInFile.next()           textInFile.hasNext()
textInFile.nextLine()       textInFile.hasNextLine()

textInFile.nextByte()       textInFile.hasNextByte()
textInFile.nextShort()      textInFile.hasNextShort()
textInFile.nextLong()       textInFile.hasNextLong()
textInFile.nextFloat()      textInFile.hasNextFloat()
textInFile.nextBoolean()    textInFile.hasNextBoolean()

textInFile.close()

Binary Files

Classes and Methods for Program Output to a Binary File

ObjectOutputStream binaryOutFile = new ObjectOutputStream(new FileOutputStream("somefile.dat"));
ObjectOutputStream binaryOutFile = new ObjectOutputStream(new FileOutputStream(new File("somefile.dat")));

binaryOutFile.writeInt(someInt)
binaryOutFile.writeDouble(someDouble)
binaryOutFile.writeUTF(someString)
binaryOutFile.writeObject(someSerializableObject)

binaryOutFile.writeByte(someByte)
binaryOutFile.writeShort(someShort)
binaryOutFile.writeLong(someLong)
binaryOutFile.writeFloat(someFloat)
binaryOutFile.writeBoolean(someBoolean)

binaryOutFile.close()

Classes and Methods for Program Input from a Binary File

ObjectInputStream binaryInFile = new ObjectInputStream(new FileInputStream("somefile.dat"));
ObjectInputStream binaryInFile = new ObjectInputStream(new FileInputStream(new File("somefile.dat")));

someInt = binaryInFile.readInt()
someDouble = binaryInFile.readDouble()
someString = binaryInFile.readUTF()
someSerializableObject = (appropriate_cast)binaryInFile.readObject()

someByte = binaryInFile.readByte()
someShort = binaryInFile.readShort()
someLong = binaryInFile.readLong()
someFloat = binaryInFile.readFloat()
someBoolean = binaryInFile.readBoolean()

binaryInFile.close()

A Class for Creating a File Object from Any File, and Some of Its Methods

The File Class

File f = new File("somefile.txt");

Some Methods of the File Class

Some Potential I/O-Related Exceptions