I am new to hibernate
I got following classes
Code:
@Entity
@Table(name="applications")
public class Application  implements java.io.Serializable  {
    private int id;
    private Set<Job> jobs = new HashSet<Job>();
    private String name;
    private String curretnVersion;
    private Date createdAt;
    private Date updatedAt;
    private String description;
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    @Column(name="name",nullable=false, length=50, unique=true)
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Column(name="current_version",length=50)
    public String getCurretnVersion() {
        return curretnVersion;
    }
    public void setCurretnVersion(String curretnVersion) {
        this.curretnVersion = curretnVersion;
    }
    @Column(name="updated_at",nullable=false)
    public Date getUpdatedAt() {
        return updatedAt;
    }
    public void setUpdatedAt(Date updatedAt) {
        this.updatedAt = updatedAt;
    }
    @Column(name="created_at",nullable=false)
    public Date getCreatedAt() {
        return createdAt;
    }
    public void setCreatedAt(Date createdAt) {
        this.createdAt = createdAt;
    }
    @Column(name="description",columnDefinition = "text")
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    @OneToMany(fetch = FetchType.LAZY)
    @NotNull
    public Set<Job> getJobs() {
        return jobs;
    }
    public void setJobs(Set<Job> jobs) {
        this.jobs = jobs;
    }
}
@Entity
@Table(name="job_statuses")
public class JobStatus {
    int id;
    String name;
    String description;
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    @Column(name="name",nullable =false, unique=true, length=50)
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Column(name="description",columnDefinition = "text")
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
}
@Entity
@Table(name = "job_types")
public class JobType {
    private int id;
    private String name;
    private String description;
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    @Column(name="name", nullable=false,length=20,unique=true)
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Column(name="description",columnDefinition = "text")
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
}
@Entity
@Table(name = "jobs")
public class Job  implements java.io.Serializable {
    private int Id;
    private Job job;
    private JobType jobType;
    private JobStatus jobStatus;
    private int priority;
    private Set<Application> applications = new HashSet<Application>(0);
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    public int getId() {
        return Id;
    }
    public void setId(int id) {
        Id = id;
    }
    @OneToOne(fetch = FetchType.LAZY)
    @NotNull
    @JoinColumn(name="job_type_id")
    public JobType getJobType() {
        return jobType;
    }
    public void setJobType(JobType jobType) {
        this.jobType = jobType;
    }
    @OneToOne(fetch = FetchType.LAZY)
    @NotNull
    @JoinColumn(name="job_status_id")
    public JobStatus getJobStatus() {
        return jobStatus;
    }
    public void setJobStatus(JobStatus jobStatus) {
        this.jobStatus = jobStatus;
    }
    @Column(name="priority",nullable=false)
    public int getPriority() {
        return priority;
    }
    public void setPriority(int priority) {
        this.priority = priority;
    }
    @OneToMany(fetch = FetchType.LAZY, mappedBy="job")
    @NotNull
    public Set<Application> getApplications() {
        return this.applications;
    }
    public void setApplications(Set<Application> applications) {
        this.applications = applications;
    }
}
and the main
Code:
   public static void main(String[] args) {
      System.out.println((new SimpleDateFormat("HH:mm:ss:SSS")).format(new Date()));      
      Session session = HibernateUtil.getSessionFactory().openSession();
      System.out.println((new SimpleDateFormat("HH:mm:ss:SSS")).format(new Date()));
      Transaction tx = session.beginTransaction();
      //Application
      Application app = new Application();
      app.setName("GW");
      app.setCreatedAt(new Date());
      app.setUpdatedAt(new Date());
      app.setCurretnVersion("1.0");
      //Job Type
      JobType jType = new JobType();
      jType.setDescription("new type");
      jType.setName("banboo");
      session.save(jType);
      //Job Status
      JobStatus js = new JobStatus();
      js.setName("waiting");
      session.save(js);      
      
      //first job
      Job job1 = new Job();
      job1.setPriority(3);      
      job1.setJobType(jType);
      job1.setJobStatus(js);
      job1.getApplications().add(app);
      app.getJobs().add(job1);
      session.saveOrUpdate(app);
      session.saveOrUpdate(job1);
      tx.commit();
      session.close();
      System.out.println((new SimpleDateFormat("HH:mm:ss:SSS")).format(new Date()));
   }
It is OK when i run the main first time. When I ran the second time. I got the following error.
 ERROR: duplicate key value violates unique constraint "uk_jidxac21t4vg1tmees14dwyo1"
  Detail: Key (name)=(banboo) already exists.
How to solve the problem?
Thanks