CODEWITHSUNDEEP
java
Aamir
Aamir

Reputation: 2424

stream closed : Runtime error message

// On running Aamir class I am getting this error.

import java.io.Externalizable;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;

public class Aamir {

    public static void main(String[] args)  throws Exception {


        Externalize();
        deExternalize();    
    }

  public static void Externalize() throws IOException {


    Person p1 = new Person();
    p1.name = "aamir";
    p1.age = 22;
    p1.weight = 60.80;

    Person p2 = new Person();
    p2.name = "zahid";
    p2.age = 26;
    p2.weight = 64.88;

    FileOutputStream fout = new FileOutputStream("dev.txt");
    ObjectOutputStream out = new ObjectOutputStream(fout);

    p1.writeExternal(out);
    p2.writeExternal(out);

    out.flush();        
    out.close();
}

    public static void deExternalize() throws IOException, ClassNotFoundException {

        FileInputStream fin = new FileInputStream("dev.ser");
        ObjectInputStream in = new ObjectInputStream(fin);

        Person p3 = new Person();
        p3.readExternal(in);

        Person p4 = new Person();
        p4.readExternal(in);
   }
}

class Person implements Externalizable  {

    String name;
    int age;
    double weight;

  public void writeExternal(ObjectOutput out) throws IOException {

    out.writeUTF(name);
    out.writeInt(age);
    out.writeDouble(weight);
     out.flush();
     out.close();
  }

  public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {


    name = in.readUTF();
    age = in.readInt();
    weight = in.readDouble();

    System.out.println(name);
    System.out.println(age);
    System.out.println(weight);


}

}

Upvotes: 0

Views: 394

Answers (4)

foxt7ot
foxt7ot

Reputation: 2515

The reason you were getting runtime exception is because you we closing ObjectOutputStream resource but again through that "out" reference you are trying to write p2 data. So here is the correct code

import java.io.Externalizable;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;

class Aamir {

    public static void main(String[] args)  throws Exception {


        Externalize();
        deExternalize();    
    }

  public static void Externalize() throws IOException {


    Person p1 = new Person();
    p1.name = "aamir";
    p1.age = 22;
    p1.weight = 60.80;

    Person p2 = new Person();
    p2.name = "zahid";
    p2.age = 26;
    p2.weight = 64.88;

    FileOutputStream fout = new FileOutputStream("dev.txt");
    ObjectOutputStream out = new ObjectOutputStream(fout);

    p1.writeExternal(out);
    p2.writeExternal(out);

    out.flush();        
   out.close();
}

    public static void deExternalize() throws IOException, ClassNotFoundException {

        FileInputStream fin = new FileInputStream("dev.ser");
        ObjectInputStream in = new ObjectInputStream(fin);

        Person p3 = new Person();
        p3.readExternal(in);

        Person p4 = new Person();
        p4.readExternal(in);
   }
}

class Person implements Externalizable  {

    String name;
    int age;
    double weight;

  public void writeExternal(ObjectOutput out) throws IOException {

    out.writeUTF(name);
    out.writeInt(age);
    out.writeDouble(weight);
    // out.flush();
     //out.close();
  }

  public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {


    name = in.readUTF();
    age = in.readInt();
    weight = in.readDouble();

    System.out.println(name);
    System.out.println(age);
    System.out.println(weight);


}
}

Upvotes: 1

David Limkys
David Limkys

Reputation: 5123

You try and close the ObjectOutputStream twice.

in: 

    FileOutputStream fout = new FileOutputStream("dev.txt");
ObjectOutputStream out = new ObjectOutputStream(fout);

p1.writeExternal(out);
p2.writeExternal(out);

out.flush();        
out.close(); <-----

and here:

public void writeExternal(ObjectOutput out) throws IOException {

out.writeUTF(name);
out.writeInt(age);
out.writeDouble(weight);
 out.flush();
 out.close(); <-----

You should not close it in writeExternal.

Upvotes: 1

fge
fge

Reputation: 121692

You .close() the stream in .writeExternal(); you should not.

It is never said in the contract of Externalizable that this method should close the stream; what if a class inherits you and calls super.writeExternal()?

Upvotes: 1

Peter Lawrey
Peter Lawrey

Reputation: 533432

You are getting an error because you are trying to write to the stream after you closed it.

You don't need to flush or close the stream in writeExternal.

Upvotes: 1

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