1000+ Java MCQ Questions & Answers

593). Which of these is a process of writing the state of an object to a byte stream?

[A]Serialization
[B]Externalization
[C]File Filtering
[D]All of the mentioned

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594). Which of these process occur automatically by the java runtime system?

[A]Serialization
[B]Garbage collection
[C]File Filtering
[D]All of the mentioned

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595). Which of these is an interface for control over serialization and deserialization?

[A]Serializable
[B]Externalization
[C]FileFilter
[D]ObjectInput

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596). Which of these interface extends DataOutput interface?

[A]Serializable
[B]Externalization
[C]ObjectOutput
[D]ObjectInput

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597). Which of these is a method of ObjectOutput interface used to finalize the output state so that any buffers are cleared?

[A]clear()
[B]flush()
[C]fflush()
[D]close()

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598). Which of these is method of ObjectOutput interface used to write the object to input or output stream as required?

[A] write()
[B]Write()
[C]StreamWrite()
[D]writeObject()

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599). What will be the output of the following Java program?

    import java.io.*;
    class serialization 
    {
        public static void main(String[] args) 
        {
            try 
            {
                Myclass object1 = new Myclass("Hello", -7, 2.1e10);
	        FileOutputStream fos = new FileOutputStream("serial");
	        ObjectOutputStream oos = new ObjectOutputStream(fos);
                oos.writeObject(object1);
                oos.flush();
                oos.close();
	    }
	    catch(Exception e) 
            {
	        System.out.println("Serialization" + e);
                System.exit(0);
            }
	    try  
            {
                Myclass object2;
	        FileInputStream fis = new FileInputStream("serial");
	        ObjectInputStream ois = new ObjectInputStream(fis);
                object2 = (Myclass)ois.readObject();
                ois.close();
	        System.out.println(object2);		    	
	    }
	    catch (Exception e) 
            {
                System.out.print("deserialization" + e);
	        System.exit(0);
	    }
        }
    }
    class Myclass implements Serializable 
    {
	String s;
	int i;
	double d;
        Myclass (String s, int i, double d)
        {
	    this.d = d;
	    this.i = i;
	    this.s = s;
	}
    }

[A] s=Hello; i=-7; d=2.1E10
[B] Hello; -7; 2.1E10
[C]s; i; 2.1E10
[D]Serialization

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600). What will be the output of the following Java program?

    import java.io.*;
    class serialization 
    {
        public static void main(String[] args) 
        {
            try 
            {
                Myclass object1 = new Myclass("Hello", -7, 2.1e10);
	        FileOutputStream fos = new FileOutputStream("serial");
	        ObjectOutputStream oos = new ObjectOutputStream(fos);
                oos.writeObject(object1);
                oos.flush();
                oos.close();
	    }
	    catch(Exception e) 
            {
	        System.out.println("Serialization" + e);
                System.exit(0);
            }
	    try
            {
	        int x;
	        FileInputStream fis = new FileInputStream("serial");
	        ObjectInputStream ois = new ObjectInputStream(fis);
                x = ois.readInt();
                ois.close();
	        System.out.println(x);		    	
	    }
	    catch (Exception e)
            {
                System.out.print("deserialization");
	        System.exit(0);
	    }
        }
    }
    class Myclass implements Serializable
    {
	String s;
	int i;
	double d;
        Myclass(String s, int i, double d)
        {
	    this.d = d;
	    this.i = i;
	    this.s = s;
	}
    }

[A] -7
[B]Hello
[C]2.1E10
[D]deserialization

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601). What will be the output of the following Java program?

    import java.io.*;
    class Chararrayinput
    {
        public static void main(String[] args) 
        {
	    String obj  = "abcdefgh";
            int length = obj.length();
            char c[] = new char[length];
            obj.getChars(0, length, c, 0);
            CharArrayReader input1 = new CharArrayReader(c);
            CharArrayReader input2 = new CharArrayReader(c, 1, 4);
            int i;
            int j;
            try 
            {
		while ((i = input1.read()) == (j = input2.read()))
                {
                    System.out.print((char)i);
                }
       	    } 
            catch (IOException e) 
            {
                e.printStackTrace();
	    }
	}
    }

[A]abc
[B]abcd
[C]abcde
[D] None of the mentioned

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602). What will be the output of the following Java program?

    import java.io.*;
    class streams
    {
        public static void main(String[] args) 
        {
            try
            {
	        FileOutputStream fos = new FileOutputStream("serial");
	        ObjectOutputStream oos = new ObjectOutputStream(fos);
                oos.writeFloat(3.5);
                oos.flush();
                oos.close();
	    }
	    catch(Exception e)
            {
	        System.out.println("Serialization" + e);
                System.exit(0);
            }
	    try 
            {
	        float x;
	        FileInputStream fis = new FileInputStream("serial");
	        ObjectInputStream ois = new ObjectInputStream(fis);
                x = ois.readInt();
                ois.close();
	        System.out.println(x);		    	
	    }
	    catch (Exception e)
            {
                System.out.print("deserialization");
	        System.exit(0);
	    }
        }
    }

[A]3
[B]3.5
[C]serialization
[D]deserialization

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