JPA Entity for DEMO.

Sample.java

package com.sample.entity;

import java.math.BigDecimal;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.IdClass;
import javax.persistence.Lob;
import javax.persistence.Table;

@Entity
@Table(name = "Sample")
@IdClass(SampleCPK.class)
public class Sample {

	@Id
	@Column(nullable=false)
	private String id;

	@Id
	@Column(nullable=false)
	private BigDecimal sNo;

	@Column
	private String attachName;

	@Column
	private String attachType;

	@Lob
	@Column
	private byte[] attachFile;
	
	/*
	 * This constructor is only for JPA.
	 * */
	Sample() {
	}

  /*
    Getters & Setters...
  */
	
}

SampleCPK.java

package com.sample.entity;

import java.io.Serializable;
import java.math.BigDecimal;

public class SampleCPK implements Serializable {
	private String id;
	
	private BigDecimal sNo;

	public SampleCPK(){}

	public String getId() {
		return id;
	}

	public BigDecimal getSNo() {
		return sNo;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((id == null) ? 0 : id.hashCode());
		result = prime * result + sNo.intValue();
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		SampleCPK other = (SampleCPK) obj;
		if (id == null) {
			if (other.id != null)
				return false;
		if (sNo != other.sNo)
			return false;
		return true;
	}
	
}