ObjectOutputStream write(byte[], int, int) in Java

write(byte[], int, int): This method is available in the java.io.ObjectOutputStream class of Java.

Syntax:

void java.io.ObjectOutputStream.write(byte[] buf, int off, int len) throws IOException

This method takes three arguments. This method writes a sub array of bytes.

Parameters: Three parameters are required for this method.

buf: the data to be written.

off: the start offset in the data.

len: the number of bytes that are written.

Returns: NA

Throws:

1. IOException - If an I/O error has occurred.

2. NullPointerException - If buf is null.

3. IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than buf.length - off.

Approach 1: When no exception

Java

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;

public class ObjectOutputStreamwrite3 {
    public static void main(String[] args) throws IOException {

        FileOutputStream fileStream = new FileOutputStream("D:\\hello.txt");

        ObjectOutputStream objStream = new ObjectOutputStream(fileStream);

        byte buf[] = { 'a', 'b', 'c', 'd', 'e', 'f' };
        int off = 0, len = 3;
        objStream.write(buf, off, len);
        System.out.println("Successfully writes to the stream");

        objStream.close();
    }
}

Output:

Successfully writes to the stream

Approach 2: NullPointerException 

Java

package com.ObjectOutputStream;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;

public class ObjectOutputStreamwrite3 {
    public static void main(String[] args) throws IOException {

        FileOutputStream fileStream = new FileOutputStream("D:\\hello.txt");

        ObjectOutputStream objStream = new ObjectOutputStream(fileStream);

        byte buf[] = null;
        int off = 0, len = 3;
        objStream.write(buf, off, len);
        System.out.println("Successfully writes to the stream");

        objStream.close();
    }
}

Output:

Exception in thread "main" java.lang.NullPointerException
	at java.base/java.io.ObjectOutputStream.write(ObjectOutputStream.java:710)
	at com.ObjectOutputStream.ObjectOutputStreamwrite3.main(ObjectOutputStreamwrite3.java:16)

Approach 3: IndexOutOfBoundsException 

Java

package com.ObjectOutputStream;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;

public class ObjectOutputStreamwrite3 {
    public static void main(String[] args) throws IOException {

        FileOutputStream fileStream = new FileOutputStream("D:\\hello.txt");

        ObjectOutputStream objStream = new ObjectOutputStream(fileStream);

        byte buf[] = { 'a', 'b', 'c', 'd', 'e', 'f' };
        int off = 0, len = 13;
        objStream.write(buf, off, len);
        System.out.println("Successfully writes to the stream");

        objStream.close();
    }
}

Output:

Exception in thread "main" java.lang.IndexOutOfBoundsException
	at java.base/java.io.ObjectOutputStream.write(ObjectOutputStream.java:714)
	at com.ObjectOutputStream.ObjectOutputStreamwrite3.main(ObjectOutputStreamwrite3.java:16)

Some more methods of ObjectOutputStream

close(): This method must be called to release any resources associated with the stream.

defaultWriteObject(): This method writes the non-static and non-transient fields of the current class to this stream.

flush(): This method flushes the stream.

putFields(): This method retrieves the object used to buffer persistent fields to be written to the stream.

reset(): The state is reset to be the same as a new ObjectOutputStream.

useProtocolVersion(int): This method specifies the stream protocol version to use when writing the stream.

write(byte[]): This method writes an array of bytes. 

write(int): This method writes a byte.

writeBoolean(boolean): This method writes a boolean.

writeByte(int): This method writes an 8-bit byte.

writeBytes(String): This method writes a String as a sequence of bytes.

writeChar(int): This method writes a 16-bit char.

writeChars(String): This method writes a String as a sequence of chars.

writeDouble(double): This method writes a 64-bit double.

writeFields(): This method writes the buffered fields to the stream.

writeFloat(float): This method writes a 32-bit float.

writeInt(int): This method writes a 32-bit int.

writeLong(long): This method writes a 64-bit long.

writeObject(Object): This method writes the specified object to the ObjectOutputStream.

writeShort(int): This method writes a 16-bit short.

writeUnshared(Object): This method writes an "unshared" object to the ObjectOutputStream.

writeUTF(String): This method is primitive data are written of this String in modified UTF-8 format.