Java ObjectInputStream readStreamHeader() Method with Examples

by Online Tutorials Library July 22, 2022

Java ObjectInputStream readStreamHeader() Method

The readStreamHeader() method of ObjectInputStream is used to allow subclasses to read and verify their respective stream headers. It reads and verifies the magic number and version number.

Syntax

Parameter

Returns

Throws

IOException – if there are I/O errors while reading from the underlying InputStream

StreamCorruptedException – if control information in the stream is inconsistent.

Example 1

  import java.io.*;  public class ObjectInputStreamreadStreamHeaderExample1 extends ObjectInputStream {     public ObjectInputStreamreadStreamHeaderExample1(InputStream in) throws IOException {        super(in);     }       public static void main(String[] args) {        String s = “welcome to TutorAspire “;                try {           // create a new file with an ObjectOutputStream           FileOutputStream outstream = new FileOutputStream(“file1.txt”);           ObjectOutputStream objoutstream = new ObjectOutputStream(outstream);             // write something in the file           objoutstream.writeUTF(s);           objoutstream.flush();             // create an ObjectInputStream for the file we created before           ObjectInputStreamreadStreamHeaderExample1 objinstream = new ObjectInputStreamreadStreamHeaderExample1(new FileInputStream(“file1.txt”));                      // get the class for string and print the name           System.out.println(“” + objinstream.resolveObject(objinstream.readUTF()));           objinstream.readStreamHeader();        } catch (Exception ex) {            }     }  }  

Output:

welcome to TutorAspire

Example 2

  package ObjectInputStream;  import java.io.DataInputStream;  import java.io.DataOutputStream;  import java.io.FileInputStream;  import java.io.FileOutputStream;  import java.io.IOException;  import java.io.InputStream;  import java.io.ObjectInputStream;  public class ObjectInputStreamreadStreamHeaderExample2  extends ObjectInputStream {      public ObjectInputStreamreadStreamHeaderExample2(InputStream in)  throws IOException {            super(in);           this.readStreamHeader();      }     public static void main(String[] args) throws IOException {        double[] carray = {21.0, 22.0 , 23.0 , 45.0 , 67.9 , 66.0};               try {           // create file output stream         FileOutputStream   fileoutstream = new FileOutputStream(“file1.txt”);                      // create data output stream          DataOutputStream dataoutstream = new DataOutputStream(fileoutstream);                      // for each byte in the buffer           for (double b:carray) {              // write character to the dos              dataoutstream.writeDouble(b);           }                      // force bytes to the underlying stream           dataoutstream.flush();                      // create file input stream           InputStream inpstream = new FileInputStream(“file1.txt”);          //ObjectInputStreamresolveObjectExample2 objinstream = new ObjectInputStreamresolveObjectExample2(new FileInputStream(“file1.txt”));           // create new data input stream          DataInputStream datainpstream = new DataInputStream(inpstream);                     // read till end of the stream           for(int i=0;i<=carray.length;i++){                          // read double values in float format              float c = datainpstream.readFloat();            //  System.out.println(“” + objinstream.resolveObject(objinstream.readUTF()));              // print              System.out.print(”    “+c);           }         } catch(Exception e) {        }      }  }  

Output:

2.828125    0.0    2.84375    0.0    2.859375    0.0    3.1015625

Next TopicJava ObjectInputStream

available()close()defaultReadObject()java objectinputstream read()readBoolean()readChar()readClassDescriptor()readFloat()readLong()readshort()