JPA - @IdClass Examples

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.IdClass;

@Entity
@IdClass(CustomerId.class)
public class Customer {
    @Id
    private String name;
    @Id
    private String phoneNumber;

    private String address;

    public String getName() {
        return name;
    }

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

    public String getPhoneNumber() {
        return phoneNumber;
    }

    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Override
    public String toString() {
        return "Customer{" +
                "name='" + name + '\'' +
                ", phoneNumber='" + phoneNumber + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}

import java.io.Serializable;

public class CustomerId implements Serializable {
    private String name;
    private String phoneNumber;

    public String getName() {
        return name;
    }

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

    public String getPhoneNumber() {
        return phoneNumber;
    }

    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }
}

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.IdClass;
import java.util.Date;

@Entity
@IdClass(CompositeTaskId.class)
public class Task {
    @Id
    private int employeeId;
    @Id
    private int taskId;
    private String taskName;
    private Date date;

    public Task() {
    }

    public Task(int employeeId, int taskId) {
        this.employeeId = employeeId;
        this.taskId = taskId;
    }

    public String getTaskName() {
        return taskName;
    }

    public void setTaskName(String taskName) {
        this.taskName = taskName;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    @Override
    public String toString() {
        return "Task{" +
                "employeeId=" + employeeId +
                ", taskId=" + taskId +
                ", taskName='" + taskName + '\'' +
                ", date=" + date +
                '}';
    }
}

import java.io.Serializable;
import java.util.Objects;

public class CompositeTaskId implements Serializable{
    private int employeeId;
    private int taskId;

    public CompositeTaskId() {
    }

    public CompositeTaskId(int employeeId, int taskId) {
        this.employeeId = employeeId;
        this.taskId = taskId;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        CompositeTaskId taskId1 = (CompositeTaskId) o;
        if (employeeId != taskId1.employeeId) return false;
        return taskId == taskId1.taskId;
    }

    @Override
    public int hashCode() {
        return Objects.hash(employeeId, taskId);
    }
}

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.IdClass;
import javax.persistence.OneToOne;
import java.util.Date;

@Entity
@IdClass(CompositeTaskId.class)
public class Task {
    @Id
    private long taskId;
    @Id
    @OneToOne
    private Employee employee;
    private String taskName;
    private Date date;

    public Task() {
    }

    public Task(Employee employee, long taskId) {
        this.employee = employee;
        this.taskId = taskId;
    }

    public String getTaskName() {
        return taskName;
    }

    public void setTaskName(String taskName) {
        this.taskName = taskName;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    @Override
    public String toString() {
        return "Task{" +
                "taskId=" + taskId +
                ", employee=" + employee +
                ", taskName='" + taskName + '\'' +
                ", date=" + date +
                '}';
    }
}

import java.io.Serializable;
import java.util.Objects;

public class CompositeTaskId implements Serializable {
    //the names of the both fields should be same as the @Id fields in source class
    //the type of 'taskId' field is same as of the basic @Id field defined in the Task entity
    private long taskId;
    //the type of 'employee' field is same as of the @Id field defined in Employee entity.
    private long employee;

    public CompositeTaskId() {
    }

    public CompositeTaskId(long employeeId, long taskId) {
        this.employee = employeeId;
        this.taskId = taskId;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        CompositeTaskId taskId1 = (CompositeTaskId) o;
        if (employee != taskId1.employee) return false;
        return taskId == taskId1.taskId;
    }

    @Override
    public int hashCode() {
        return Objects.hash(employee, taskId);
    }
}

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.IdClass;
import javax.persistence.ManyToOne;
import java.util.Date;

@Entity
@IdClass(CompositeTaskId.class)
public class Task {
    @Id
    private long taskId;

    @Id
    @ManyToOne
    private Employee employee;

    private String taskName;
    private Date date;

    public Task() {
    }

    public Task(Employee employee, long taskId) {
        this.employee = employee;
        this.taskId = taskId;
    }


    public String getTaskName() {
        return taskName;
    }

    public void setTaskName(String taskName) {
        this.taskName = taskName;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    @Override
    public String toString() {
        return "Task{" +
                "taskId=" + taskId +
                ", employee=" + employee +
                ", taskName='" + taskName + '\'' +
                ", date=" + date +
                '}';
    }
}

import java.io.Serializable;
import java.util.Objects;

public class CompositeTaskId implements Serializable{
    private long employee;
    private long taskId;

    public CompositeTaskId() {
    }

    public CompositeTaskId(long employeeId, long taskId) {
        this.employee = employeeId;
        this.taskId = taskId;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        CompositeTaskId taskId1 = (CompositeTaskId) o;
        if (employee != taskId1.employee) return false;
        return taskId == taskId1.taskId;
    }

    @Override
    public int hashCode() {
        return Objects.hash(employee, taskId);
    }
}

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.IdClass;

@Entity
@IdClass(EmployeeId.class)
public class Employee {
    @Id
    private String firstName;
    @Id
    private String lastName;
    private String dept;

    public Employee() {
    }

    public Employee(String firstName, String lastName, String dept) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.dept = dept;
    }

    @Override
    public String toString() {
        return "Employee{" +
                "firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", dept='" + dept + '\'' +
                '}';
    }
}

import java.io.Serializable;
import java.util.Objects;

public class EmployeeId implements Serializable{
    private String firstName;
    private String lastName;

    public EmployeeId() {
    }

    public EmployeeId(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        EmployeeId that = (EmployeeId) o;

        if (!firstName.equals(that.firstName)) return false;
        return lastName.equals(that.lastName);
    }

    @Override
    public int hashCode() {
        return Objects.hash(firstName, lastName);
    }

    @Override
    public String toString() {
        return "EmployeeId{" +
                "firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                '}';
    }
}

import javax.persistence.*;
import java.util.Date;

@Entity
@IdClass(CompositeTaskId.class)
public class Task {
    @Id
    private long taskId;

    @Id
    @ManyToOne
    @JoinColumns({
            @JoinColumn(name = "FK_firstName", referencedColumnName = "firstName"),
            @JoinColumn(name = "FK_lastName", referencedColumnName = "lastName")
    })
    private Employee employee;

    private String taskName;
    private Date date;

    public Task() {
    }

    public Task(Employee employee, long taskId) {
        this.employee = employee;
        this.taskId = taskId;
    }


    public String getTaskName() {
        return taskName;
    }

    public void setTaskName(String taskName) {
        this.taskName = taskName;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    @Override
    public String toString() {
        return "Task{" +
                "taskId=" + taskId +
                ", employee=" + employee +
                ", taskName='" + taskName + '\'' +
                ", date=" + date +
                '}';
    }
}

import java.io.Serializable;
import java.util.Objects;

public class CompositeTaskId implements Serializable {
    private EmployeeId employee;
    private long taskId;

    public CompositeTaskId() {
    }

    public CompositeTaskId(EmployeeId employee, long taskId) {
        this.employee = employee;
        this.taskId = taskId;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        CompositeTaskId that = (CompositeTaskId) o;

        if (taskId != that.taskId) return false;
        return employee != null ? employee.equals(that.employee) : that.employee == null;
    }

    @Override
    public int hashCode() {
        return Objects.hash(employee, taskId);
    }

    @Override
    public String toString() {
        return "CompositeTaskId{" +
                "employee=" + employee +
                ", taskId=" + taskId +
                '}';
    }
}