package com.cms.model;
import org.hibernate.*;
import java.sql.*;
import java.sql.SQLException;

public class blob_to_string {
public static void main(String args[]){

String data = “hello world”;
Blob blob = Hibernate.createBlob(data.getBytes());

byte[] bdata;
try {
bdata = blob.getBytes(1, (int)blob.length());
String data1 = new String(bdata);
System.out.println(data1);
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println(“ERROR”);
e.printStackTrace();
}
}

}

Exception in thread “main” java.lang.UnsupportedOperationException: Blob may not be manipulated from creating session
at org.hibernate.lob.BlobImpl.excep(BlobImpl.java:104)
at org.hibernate.lob.BlobImpl.getBytes(BlobImpl.java:50)
at org.hibernate.lob.SerializableBlob.getBytes(SerializableBlob.java:69)
at com.cms.model.blob_to_string.main(blob_to_string.java:15)

You often see magic numbers embedded in file formats, because files can be sent around rather promiscuously and lose any metadata about how they were created. However magic numbers are also sometimes used for in-memory data structures, like ioctl() calls.

A quick check of the magic number before processing the file or data structure allows one to signal errors early, rather than schlep all the way through potentially lengthy processing in order to announce that the input was complete balderdash.