Automatic database index creation using JPA (https://www.j-dimension.com/automatic-database-index-creation-with-the-java-persistence-api/)

JpaIndex.java

package com.jdimension.jpaindextest;

import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Index;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

/**
 * JPA entity class with automatic index creation
 * @author j-dimension
 */
@Entity
@Table(name = "JpaIndex",
       indexes = {@Index(name = "idx_id",  columnList="id", unique = true),
                    @Index(name = "idx_somevalue", columnList="someValue",     unique = false)})
@NamedQueries({
    @NamedQuery(name = "JpaIndex.findAll", query = "SELECT a FROM JpaIndex a"),
    @NamedQuery(name = "JpaIndex.findBySomeValue", query = "SELECT a FROM JpaIndex a WHERE a.someValue = :someValue")})
public class JpaIndex implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    
    private String someValue;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof JpaIndex)) {
            return false;
        }
        JpaIndex other = (JpaIndex) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "com.jdimension.jpaindextest.JpaIndex[ id=" + id + " ]";
    }

    /**
     * @return the someValue
     */
    public String getSomeValue() {
        return someValue;
    }

    /**
     * @param someValue the someValue to set
     */
    public void setSomeValue(String someValue) {
        this.someValue = someValue;
    }
    
}

Also see my blog post for this topic: https://www.j-dimension.com/automatic-database-index-creation-with-the-java-persistence-api/