Hibernate one-to-one bidirectional mapping using annotation

Hi friends,

Here i’m gonna tell you something about Hibernate mapping, Now, it’s all about one-to-one bidirectional mapping. Bidirectional mapping means, the child knows its parent’s properties/characteristics. Simply, we can say, from child’s point of view, it can easily identify who its parent is.

Here, i’m exploring a bidirectional mapping between a sim and a mobile. I just assume each phone is having exactly one sim and vice versa, even though it’s not practical in real world.

Here’s the DAO class, DAO.java.

public class DAO {

    private static final ThreadLocal THREAD = new ThreadLocal();

    protected DAO() {
    }

    public static Session getSession() {
        Session session = (Session) DAO.THREAD.get();
        if (session == null) {
            session = HibernateUtil.getSessionFactory().openSession();
            DAO.THREAD.set(session);
            getSession().setFlushMode(FlushMode.COMMIT);
        }
        return session;
    }

    protected static void begin() {
        getSession().beginTransaction();
    }

    protected static void commit() {
        getSession().getTransaction().commit();
    }

    protected static void rollback() {
        getSession().getTransaction().rollback();
        getSession().close();
        DAO.THREAD.set(null);
    }

    protected static void flush() {
        getSession().flush();
    }

    protected static void close() {
        getSession().close();
        DAO.THREAD.set(null);
    }
}

The hibernate configuration file, hibernate.cfg.xml.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hba</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">password</property>
        <property name="hibernate.show_sql">true</property>
        <property name="hibernate.hbm2ddl.auto">update</property>
        <mapping class="hba.pojo.o2o_b_mobile"/>
        <mapping class="hba.pojo.o2o_b_sim"/>
    </session-factory>
</hibernate-configuration>

Here’s the mobile POJO, o2o_b_mobile.java

package hba.pojo;

import java.io.Serializable;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name = "MOBILE", catalog = "hba")
public class o2o_b_mobile implements Serializable {

    private String imei, model;
    private o2o_b_sim sim;

    @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    @JoinColumn(name = "MOB_SIM")
    public o2o_b_sim getSim() {
        return sim;
    }

    @Column(name = "MOB_MODEL", length = 20, nullable = false)
    public String getModel() {
        return model;
    }

    @Id
    @Column(name = "MOB_IMEI", length = 10, nullable = false)
    public String getImei() {
        return imei;
    }

    public void setSim(o2o_b_sim sim) {
        this.sim = sim;
    }

    public void setImei(String imei) {
        this.imei = imei;
    }

    public void setModel(String model) {
        this.model = model;
    }
}

Download mobile POJO

Here’s the sim POJO, o2o_b_sim.java

package hba.pojo;

import java.io.Serializable;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.Table;


@Entity
@Table(name = "SIM", catalog = "hba")
public class o2o_b_sim implements Serializable {

    private String no;
    private String company;
    private o2o_b_mobile mobile;

    @OneToOne(mappedBy = "sim", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    public o2o_b_mobile getMobile() {
        return mobile;
    }

    @Column(name = "SIM_COMPANY", length = 20, nullable = false)
    public String getCompany() {
        return company;
    }

    @Id
    @Column(name = "SIM_NO", length = 20)
    public String getNo() {
        return no;
    }

    public void setCompany(String company) {
        this.company = company;
    }

    public void setMobile(o2o_b_mobile mobile) {
        this.mobile = mobile;
    }

    public void setNo(String no) {
        this.no = no;
    }
}

Download sim POJO

Here’s the save() method of o2o_b_mobile_sim.java.

package hba.biz;

import hba.dao.DAO;
import hba.pojo.o2o_b_mobile;
import hba.pojo.o2o_b_sim;

public class o2o_b_mobile_sim extends DAO {

    private o2o_b_mobile mobile = new o2o_b_mobile();
    private o2o_b_sim sim = new o2o_b_sim();

    public void save() throws Exception {
        try {
            begin();
            sim.setNo("9496351113");
            sim.setCompany("BSNL");
            mobile.setImei("123456789");
            mobile.setModel("SAMSUNG CORBY");
            mobile.setSim(sim);
            getSession().save(mobile);
            commit();
        } catch (Exception e) {
            rollback();
            throw new Exception("Exception in save : " + e.getMessage());
        } finally {
            flush();
            close();
        }
    }

    public static void main(String[] args) {
        try {
            o2o_b_mobile_sim ms = new o2o_b_mobile_sim();
            ms.save();
        } catch (Exception e) {
            System.out.println("Exception : " + e.getMessage() + "Cause : " + e.getCause());
        }
    }
}

Download the save() method

The output of the above save() method will be

Hibernate: select o2o_b_sim_.SIM_NO, o2o_b_sim_.SIM_COMPANY as SIM2_9_ from hba.SIM o2o_b_sim_ where o2o_b_sim_.SIM_NO=?
Hibernate: insert into hba.SIM (SIM_COMPANY, SIM_NO) values (?, ?)
Hibernate: insert into hba.MOBILE (MOB_MODEL, MOB_SIM, MOB_IMEI) values (?, ?, ?)

Here, the join column will be created on mobile side.

Another design implementation looks like this.

The mobile POJO class, o2o_b_mobile.java.

package hba.pojo;

import java.io.Serializable;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name = "MOBILE", catalog = "hba")
public class o2o_b_mobile implements Serializable {

    private String imei, model;
    private o2o_b_sim sim;

    @OneToOne(mappedBy = "mobile", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    @JoinColumn(name = "MOB_IMEI")
    public o2o_b_sim getSim() {
        return sim;
    }

    @Column(name = "MOB_MODEL", length = 20, nullable = false)
    public String getModel() {
        return model;
    }

    @Id
    @Column(name = "MOB_IMEI", length = 10, nullable = false)
    public String getImei() {
        return imei;
    }

    public void setSim(o2o_b_sim sim) {
        this.sim = sim;
    }

    public void setImei(String imei) {
        this.imei = imei;
    }

    public void setModel(String model) {
        this.model = model;
    }
}

The next POJO class, o2o_b_sim.java.

package hba.pojo;

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.Table;
import org.hibernate.annotations.Cascade;

@Entity
@Table(name = "SIM", catalog = "hba")
public class o2o_b_sim implements Serializable {

    private String no;
    private String company;
    private o2o_b_mobile mobile;

    @OneToOne(fetch = FetchType.EAGER)
    @Cascade(org.hibernate.annotations.CascadeType.SAVE_UPDATE)
    public o2o_b_mobile getMobile() {
        return mobile;
    }

    @Column(name = "SIM_COMPANY", length = 20, nullable = false)
    public String getCompany() {
        return company;
    }

    @Id
    @Column(name = "SIM_NO", length = 20)
    public String getNo() {
        return no;
    }

    public void setCompany(String company) {
        this.company = company;
    }

    public void setMobile(o2o_b_mobile mobile) {
        this.mobile = mobile;
    }

    public void setNo(String no) {
        this.no = no;
    }
}

The save() method

package hba.biz;

import hba.dao.DAO;
import hba.pojo.o2o_b_mobile;
import hba.pojo.o2o_b_sim;

public class o2o_b_mobile_sim extends DAO {

    private o2o_b_mobile mobile = new o2o_b_mobile();
    private o2o_b_sim sim = new o2o_b_sim();

    public void save() throws Exception {
        try {
            begin();
            sim.setNo("9496351113");
            sim.setCompany("BSNL");
            mobile.setImei("123456789");
            mobile.setModel("SAMSUNG CORBY");
            mobile.setSim(sim);
            sim.setMobile(mobile);
            getSession().save(mobile);
            commit();
        } catch (Exception e) {
            rollback();
            throw new Exception("Exception in save : " + e.getMessage());
        } finally {
            flush();
            close();
        }
    }

    public static void main(String[] args) {
        try {
            o2o_b_mobile_sim ms = new o2o_b_mobile_sim();
            ms.save();
        } catch (Exception e) {
            System.out.println("Exception : " + e.getMessage() + "Cause : " + e.getCause());
        }
    }
}

Here, we have mapped sim to mobile and mobile to sim, and the join column will be created on sim side. The output of the above save() method will be

Hibernate: select o2o_b_sim_.SIM_NO, o2o_b_sim_.SIM_COMPANY as SIM2_9_, o2o_b_sim_.mobile_MOB_IMEI as mobile3_9_ from hba.SIM o2o_b_sim_ where o2o_b_sim_.SIM_NO=?
Hibernate: insert into hba.MOBILE (MOB_MODEL, MOB_IMEI) values (?, ?)
Hibernate: insert into hba.SIM (SIM_COMPANY, mobile_MOB_IMEI, SIM_NO) values (?, ?, ?)

Retrieving mobile details, the listMobile() method.

package hba.biz;

import hba.dao.DAO;
import hba.pojo.o2o_b_mobile;
import hba.pojo.o2o_b_sim;
import java.util.List;

public class o2o_b_mobile_sim extends DAO {

    public void listMobile() {
        try {
            begin();
            List<o2o_b_mobile> mobiles = getSession().createCriteria(o2o_b_mobile.class).list();
            for (o2o_b_mobile Mobile : mobiles) {
                System.out.println("IMEI: " + Mobile.getImei());
                System.out.println("Model: " + Mobile.getModel());
                o2o_b_sim Sim = Mobile.getSim();
                System.out.println("Sim No: " + Sim.getNo());
                System.out.println("Sim Company: " + Sim.getCompany());
            }
            commit();
        } catch (Exception e) {
            rollback();
            System.out.println("Exception : " + e.getMessage() + "Cause : " + e.getCause());
        } finally {
            flush();
            close();
        }
    }

    public static void main(String[] args) {
        try {
            o2o_b_mobile_sim ms = new o2o_b_mobile_sim();
            ms.listMobile();
        } catch (Exception e) {
            System.out.println("Exception : " + e.getMessage() + "Cause : " + e.getCause());
        }
    }
}

The output will be

Hibernate: select this_.MOB_IMEI as MOB1_8_1_, this_.MOB_MODEL as MOB2_8_1_, this_.MOB_SIM as MOB3_8_1_, o2o_b_sim2_.SIM_NO as SIM1_9_0_, o2o_b_sim2_.SIM_COMPANY as SIM2_9_0_ from hba.MOBILE this_ left outer join hba.SIM o2o_b_sim2_ on this_.MOB_SIM=o2o_b_sim2_.SIM_NO
Hibernate: select o2o_b_mobi0_.MOB_IMEI as MOB1_8_1_, o2o_b_mobi0_.MOB_MODEL as MOB2_8_1_, o2o_b_mobi0_.MOB_SIM as MOB3_8_1_, o2o_b_sim1_.SIM_NO as SIM1_9_0_, o2o_b_sim1_.SIM_COMPANY as SIM2_9_0_ from hba.MOBILE o2o_b_mobi0_ left outer join hba.SIM o2o_b_sim1_ on o2o_b_mobi0_.MOB_SIM=o2o_b_sim1_.SIM_NO where o2o_b_mobi0_.MOB_SIM=?
IMEI: 123456789
Model: SAMSUNG CORBY
Sim No: 9496351113
Sim Company: BSNL

Retrieving sim details, the listSim() method, it contains mobile details as well.

package hba.biz;

import hba.dao.DAO;
import hba.pojo.o2o_b_mobile;
import hba.pojo.o2o_b_sim;
import java.util.List;

public class o2o_b_mobile_sim extends DAO {

    public void listSim() throws Exception {
        try {
            begin();
            List<o2o_b_sim> sims = getSession().createQuery("from o2o_b_sim where no=:no").setString("no", "9496351113").list();
            System.out.println("List : " + sims);
            for (o2o_b_sim Sim : sims) {
                System.out.println("No: " + Sim.getNo());
                System.out.println("Company: " + Sim.getCompany());
                o2o_b_mobile Mobile = Sim.getMobile();
                System.out.println("Mobile IMEI: " + Mobile.getImei());
                System.out.println("Mobile Model: " + Mobile.getModel());
            }
            commit();
        } catch (Exception e) {
            rollback();
            System.out.println("Exception : " + e.getMessage() + "Cause : " + e.getCause());
        } finally {
            flush();
            close();
        }
    }

    public static void main(String[] args) {
        try {
            o2o_b_mobile_sim ms = new o2o_b_mobile_sim();
            ms.listSim();
        } catch (Exception e) {
            System.out.println("Exception : " + e.getMessage() + "Cause : " + e.getCause());
        }
    }
}

The output will be

Hibernate: select o2o_b_sim0_.SIM_NO as SIM1_9_, o2o_b_sim0_.SIM_COMPANY as SIM2_9_ from hba.SIM o2o_b_sim0_ where o2o_b_sim0_.SIM_NO=?
Hibernate: select o2o_b_mobi0_.MOB_IMEI as MOB1_8_1_, o2o_b_mobi0_.MOB_MODEL as MOB2_8_1_, o2o_b_mobi0_.MOB_SIM as MOB3_8_1_, o2o_b_sim1_.SIM_NO as SIM1_9_0_, o2o_b_sim1_.SIM_COMPANY as SIM2_9_0_ from hba.MOBILE o2o_b_mobi0_ left outer join hba.SIM o2o_b_sim1_ on o2o_b_mobi0_.MOB_SIM=o2o_b_sim1_.SIM_NO where o2o_b_mobi0_.MOB_SIM=?
List : [hba.pojo.o2o_b_sim@9a9b65]
No: 9496351113
Company: BSNL
Mobile IMEI: 123456789
Mobile Model: SAMSUNG CORBY

Thanks.

Hibernate one-to-one unidirectional mapping using annotation

Hi friends,

Here i’m gonna tell you something about Hibernate mapping. I’m not exploring the core of hibernate Object Relational Mapping (ORM) tool. Let’s me come to the point.

I’m giving you an example of student and address. Since the relation is one to one, each student has exactly one address.

The DAO class looks like this, DAO.java.

package hba.dao;

import hba.util.HibernateUtil;
import org.hibernate.FlushMode;
import org.hibernate.Session;

public class DAO {

    private static final ThreadLocal THREAD = new ThreadLocal();

    protected DAO() {
    }

    public static Session getSession() {
        Session session = (Session) DAO.THREAD.get();
        if (session == null) {
            session = HibernateUtil.getSessionFactory().openSession();
            DAO.THREAD.set(session);
            getSession().setFlushMode(FlushMode.COMMIT);
        }
        return session;
    }

    protected static void begin() {
        getSession().beginTransaction();
    }

    protected static void commit() {
        getSession().getTransaction().commit();
    }

    protected static void rollback() {
        getSession().getTransaction().rollback();
        getSession().close();
        DAO.THREAD.set(null);
    }

    protected static void flush() {
        getSession().flush();
    }

    protected static void close() {
        getSession().close();
        DAO.THREAD.set(null);
    }
}

The hibernate configuration file, hibernate.cfb.xml.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hba</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">password1.</property>
        <property name="hibernate.show_sql">true</property>
        <property name="hibernate.hbm2ddl.auto">update</property>
        <mapping class="hba.pojo.o2o_u_student"/>
        <mapping class="hba.pojo.o2o_u_address"/>
    </session-factory>
</hibernate-configuration>

Here’s the student POJO, o2o_u_student.java.

package hba.pojo;

import java.io.Serializable;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name = "STUDENT", catalog = "hba")
public class o2o_u_student implements Serializable {

    private long std_id;
    private String std_name;
    private o2o_u_address std_address;

    @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    @JoinColumn(name = "STD_ADD_ID")
    public o2o_u_address getStd_address() {
        return std_address;
    }

    public void setStd_address(o2o_u_address std_address) {
        this.std_address = std_address;
    }

    @Id
    @GeneratedValue
    @Column(name = "STD_ID")
    public long getStd_id() {
        return std_id;
    }

    public void setStd_id(long std_id) {
        this.std_id = std_id;
    }

    @Column(name = "STD_NAME", length = 20, nullable = false)
    public String getStd_name() {
        return std_name;
    }

    public void setStd_name(String std_name) {
        this.std_name = std_name;
    }
}

Download Student POJO

Here’s the address POJO, o2o_u_address.java.

package hba.pojo;

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "ADDRESS", catalog = "hba")
public class o2o_u_address implements Serializable {

    private long add_id;
    private String add_address;

    @Column(name = "ADD_ADDRESS", length = 50, nullable = false)
    public String getAdd_address() {
        return add_address;
    }

    public void setAdd_address(String add_address) {
        this.add_address = add_address;
    }

    @Id
    @Column(name = "ADD_ID")
    public long getAdd_id() {
        return add_id;
    }

    public void setAdd_id(long add_id) {
        this.add_id = add_id;
    }
}

Download address POJO

Finally, here’s the save() method.

public class o2o_u_std_add extends DAO {
public void save() {
        try {
            begin();
            o2o_u_student student = new o2o_u_student();
            o2o_u_address address = new o2o_u_address();
            address.setAdd_id(2);
            address.setAdd_address("Sydney Place, Washington, DC 20521-4150");
            student.setStd_name("deepesh");
            student.setStd_address(address);
            getSession().save(student);
            commit();
        } catch (Exception e) {
            rollback();
            System.out.println("Exception :" + e.getMessage() + "Cause :" + e.getCause());
        } finally {
            flush();
            close();
        }
    }

public static void main(String[] args) throws Exception {
        new o2o_u_std_add().save();
    }
}

Download save() method.

The output of the above save() method will be

Hibernate: select o2o_u_addr_.ADD_ID, o2o_u_addr_.ADD_ADDRESS as ADD2_1_ from hba.ADDRESS o2o_u_addr_ where o2o_u_addr_.ADD_ID=?
Hibernate: insert into hba.STUDENT (STD_ADD_ID, STD_NAME) values (?, ?)

Thank You.

How to insert non-English languages to Mysql database using Hibernate ?

Fellas,

Here i’m going to tell you some information from my own experience. The question simply is how to insert non-English languages to mysql database using hibernate. By going through the following 3-4 steps, you can also solve your problem (only if you are facing it !), So let me start..

Step 1 : Set the default character set and collate of your database to utf8 and utf8_general_ci consecutively; by default it will be ‘latin1’. The alter query for the above purpose is..
ALTER DATABASE `dbname` CHARACTER SET utf8 COLLATE utf8_general_ci;

Step 2 : Set the default character set of your table to ‘UTF8’ as well. The query looks like this..
ALTER TABLE `tblname` CHARACTER SET utf8;

Step 3 : Change the character set of your table column to utf8.
ALTER TABLE `tblname` MODIFY `columnname` `datatype` CHARACTER SET utf8;

Step4 : Make sure that the encoding type of your JSP page is UTF-8. For that, just include this line above all of your JSP pages.

<%@page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>

Step5 : The final step.. Add these two properties to your hibernate configuration file.

Now clean and build your project, just enter a non-English language(Eg: Arabic) in the text box of your jsp page, then save it. Now you can see how it works..

Thank you..