Java.io.DataInputStream class in Java

Java.io.DataInputStream class in Java | Set 2

Difficulty Level : Hard
Last Updated : 20 Jan, 2017

Java.io.DataInputStream class in Java | Set 1

More Methods:

byte readByte() : Reads and returns one input byte.

Syntax:public final byte readByte()
                    throws IOException
Returns: the next byte of this input stream as a signed 8-bit byte.
Throws:
EOFException
IOException

float readFloat() : Reads four input bytes and returns a float value.

Syntax:public final float readFloat()
                      throws IOException
Returns :the next four bytes of this input stream, interpreted as a float.
Throws:
EOFException 
IOException

void readFully(byte[] b) : Reads some bytes from an input stream and stores them into the buffer array b.

Syntax:public final void readFully(byte[] b)
                     throws IOException
Parameters:
b - the buffer into which the data is read.
Throws:
EOFException
IOException

void readFully(byte[] b, int off, int len) : Reads len bytes from an input stream.

Syntax:public final void readFully(byte[] b,
             int off,
             int len)
                     throws IOException
Parameters:
b - the buffer into which the data is read.
off - the start offset of the data.
len - the number of bytes to read.
Throws:
EOFException 
IOException

String readLine() : Reads the next line of text from the input stream.

Syntax:
Returns: the next line of text from this input stream.
Throws:
IOException
Deprecated This method does not properly convert bytes to characters.

long readLong() : Reads eight input bytes and returns a long value.

Syntax:public final long readLong()
                    throws IOException
Returns:
the next eight bytes of this input stream, interpreted as a long.
Throws:
EOFException
IOException

short readShort() : Reads two input bytes and returns a short value.

Syntax:public final short readShort()
                      throws IOException
Returns:
the next two bytes of this input stream, interpreted as a signed 16-bit number.
Throws:
EOFException
IOException

String readUTF() : Reads a string that has been encoded using a modified UTF-8 format.

Syntax:public final String readUTF()
                     throws IOException
Returns:
a Unicode string.
Throws:
EOFException 
IOException
UTFDataFormatException

int skipBytes(int n) : Makes an attempt to skip over n bytes of data from the input stream, discarding the skipped bytes.

Syntax:public final int skipBytes(int n)
                    throws IOException
Parameters:
n - the number of bytes to be skipped.
Returns:
the actual number of bytes skipped.
Throws:
IOException

Program 2:

//Java program to demonstrate DataInputStream
// This program uses try-with-resources. It requires JDK 7 or later.
import java.io.*;
import java.lang.reflect.Array;
import java.util.Arrays;
  
class DataInputStreamDemo
{
    public static void main(String args[]) throws IOException
    {
        //writing the data.
        try ( DataOutputStream dout =
                    new DataOutputStream(new FileOutputStream("file.dat")) )
        {
            dout.writeBytes("1");
            dout.writeFloat(4.4545f);
            dout.writeUTF("geeksforgeeks");
            dout.writeChars("GeeksforGeeks\n");
            dout.writeBytes("ABCDEFG");
  
        }
  
        catch(FileNotFoundException ex)
        {
            System.out.println("Cannot Open the Output File");
            return;
        }
  
        // reading the data back.
        try ( DataInputStream din =
                    new DataInputStream(new FileInputStream("file.dat")) )
        {
  
            //illustrating readByte() method
            byte t=din.readByte();
              
            //illustrating readFloat() method
            float u=din.readFloat();
              
            //illustrating readUTF() method
            String temp=din.readUTF();
              
            //illustrating readLine() method
            String temp1=din.readLine();
  
            System.out.println("Values: " + t +" "+" "+u+" "+temp+" "+temp1 );
  
            //illustrating skipBytes() method
            //skipping "AB"
            din.skipBytes(2);
  
            //illustrating readFully() method
            byte[] b=new byte[4];
            din.readFully(b,0,4);
            System.out.println(Arrays.toString(b));
  
        }
        catch(FileNotFoundException e)
        {
            System.out.println("Cannot Open the Input File");
            return;
        }
    }
}

Output:

Values: 49  4.4545 geeksforgeeks  GeeksforGeeks 
[67, 68, 69, 70]

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