Java – Unable to get list using conditions

Unable to get list using conditions… here is a solution to the problem.

Unable to get list using conditions

public static List<Image> getList(int userId) {
      Session session = HibernateUtil.openSession();
      Transaction tx = null;
      List<Image> results = null;
      try {
      tx = session.beginTransaction();

Criteria crit = session.createCriteria(Image.class);
      crit.add(Restrictions.eq("userID",new Integer(userId)));
      results = crit.list();

tx.commit();
      }
      catch (HibernateException e) {
          System.out.println("Problem in retrieving data from database");
             if (tx!=null) tx.rollback();
             e.printStackTrace(); 
          } finally {
             session.close(); 
          }

return results;

}

Image class

@Entity
@Table(name = "image")
public class Image {
    @Id
    @Column(name = "userId")
    int userID;
    @Id
    @Column(name = "name")
    String name;
    @Column(name = "size")
    double size;
    @Column(name = "preview")
    byte[] preview;

public int getUserID() {
        return userID;
    }

public void setUserID(int userID) {
        this.userID = userID;
    }

public String getName() {
        return name;
    }

public Image() {
        super();
         TODO Auto-generated constructor stub
    }

public Image(int userID, String name, double size, byte[] preview) {
        super();
        this.userID = userID;
        this.name = name;
        this.size = size;
        this.preview = preview;
    }

public void setName(String name) {
        this.name = name;
    }

public double getSize() {
        return size;
    }

public void setSize(double size) {
        this.size = size;
    }

public byte[] getPreview() {
        return preview;
    }

public void setPreview(byte[] preview) {
        this.preview = preview;
    }

}

Here is my database
enter image description here

An image is an entity with the following properties: userId, name, size, preview.

userId + picture name is the composite primary key
I have fetched all rows with userId = 1
When I iterate through the list obtained. I get AAdhar (which is the first entry in the database) displayed 6 times instead of a different name each time.
I can’t figure out what the problem is.

Solution: Edit the correct image class code
Create the ImagePK class as described above

 @Entity
    @Table(name = "image")
    @IdClass(ImagePK.class)
    public class Image {
        @Id
        @Column(name = "userId")
        int userID;
        @Id
        @Column(name = "name")
        String name;
        @Column(name = "size")
        double size;
        @Column(name = "preview")
        byte[] preview;
    ......}

Solution

I don’t think you’re creating the composite primary key the way you want. You can create a composite primary key in hibernate – like this

public class ImagePK implements Serializable {
    protected Integer userID;
    protected String name;

public ImagePK() {}

public ImagePK(Integer userID, String name) {
        this.userID = userID;
        this.name = name;
    }
     equals, hashCode
}

Use @IdClass annotations in your Image entity class

@Entity
@Table(name = "image")
@IdClass(ImagePK.class)
public class Image {
}

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