ObjectInputStream class « ObjectInputStream « Stream for Input « File Stream

An ObjectInputStream deserializes primitive data and objects previously written using an ObjectOutputStream.

Constructor	Summary
ObjectInputStream(InputStream in)	Creates an ObjectInputStream that reads from the specified InputStream.

Return	Method	Summary
int	available()	Returns the number of bytes that can be read without blocking.
void	close()	Closes the input stream.
void	defaultReadObject()	Read the non-static and non-transient fields of the current class from this stream.
int	read()	Reads a byte of data.
int	read(byte[] buf, int off, int len)	Reads into an array of bytes.
boolean	readBoolean()	Reads in a boolean.
byte	readByte()	Reads an 8 bit byte.
char	readChar()	Reads a 16 bit char.
double	readDouble()	Reads a 64 bit double.
float	readFloat()	Reads a 32 bit float.
void	readFully(byte[] buf)	Reads bytes, blocking until all bytes are read.
void	readFully(byte[] buf, int off, int len)	Reads bytes, blocking until all bytes are read.
int	readInt()	Reads a 32 bit int.
String	readLine()	Deprecated. This method does not properly convert bytes to characters. see DataInputStream for the details and alternatives.
long	readLong()	Reads a 64 bit long.
Object	readObject()	Read an object from the ObjectInputStream.
short	readShort()	Reads a 16 bit short.
Object	readUnshared()	Reads an "unshared" object from the ObjectInputStream.
int	readUnsignedByte()	Reads an unsigned 8 bit byte.
int	readUnsignedShort()	Reads an unsigned 16 bit short.
String	readUTF()	Reads a String in modified UTF-8 format.
void	registerValidation(ObjectInputValidation obj, int prio)	Register an object to be validated before the graph is returned.
int	skipBytes(int len)	Skips bytes.


import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.EOFException;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.math.BigInteger;

public class Main {
  static final String dataFile = "data.dat";

  public static void main(String[] args) throws IOException, ClassNotFoundException {

    ObjectOutputStream out = null;
    try {
      out = new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream(dataFile)));

      out.writeObject(new BigInteger("123"));
      out.writeInt(123);
      out.writeUTF("a String");
    } finally {
      out.close();
    }

    ObjectInputStream in = null;
    try {
      in = new ObjectInputStream(new BufferedInputStream(new FileInputStream(dataFile)));
      try {
        while (true) {
          BigInteger price = (BigInteger) in.readObject();
          int unit = in.readInt();
          String desc = in.readUTF();
          System.out.println(price);
          System.out.println(unit);
          System.out.println(desc);
        }
      } catch (EOFException e) {
      }

    } finally {
      in.close();
    }
  }
}