Hibernate EntityManager OneToMany

College.java

package com.test;

import java.util.List;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToMany;

@Entity
public class College {
    private int collegeId;
    private String collegeName;
    private List<CollegeStudent> students;

    @Id
    @GeneratedValue
    public int getCollegeId() {
        return collegeId;
    }

    public void setCollegeId(int collegeId) {
        this.collegeId = collegeId;
    }

    public String getCollegeName() {
        return collegeName;
    }

    public void setCollegeName(String collegeName) {
        this.collegeName = collegeName;
    }

    @OneToMany(targetEntity = CollegeStudent.class, mappedBy = "college", 
cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    public List<CollegeStudent> getStudents() {
        return students;
    }

    public void setStudents(List<CollegeStudent> students) {
        this.students = students;
    }
}

CollegeStudent.java

package com.test;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;

@Entity
public class CollegeStudent {
    private int studentId;
    private String studentName;
    private College college;

    @Id
    @GeneratedValue
    public int getStudentId() {
        return studentId;
    }

    public void setStudentId(int studentId) {
        this.studentId = studentId;
    }

    public String getStudentName() {
        return studentName;
    }

    public void setStudentName(String studentName) {
        this.studentName = studentName;
    }

    @ManyToOne
    @JoinColumn(name = "college_id")
    public College getCollege() {
        return college;
    }

    public void setCollege(College college) {
        this.college = college;
    }
}

CollegeStudentTest.java

package com.test;

import static org.junit.Assert.*;

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;

public class CollegeStudentTest {

    static EntityManagerFactory entityManagerFactory;

    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
        entityManagerFactory = Persistence
                .createEntityManagerFactory("org.hibernate.tutorial.jpa");
    }

    @AfterClass
    public static void tearDownAfterClass() throws Exception {
        entityManagerFactory.close();
    }

    @Before
    public void setUp() throws Exception {
    }

    @After
    public void tearDown() throws Exception {
    }

    @Test
    public void test() {
        EntityManager entityManager = entityManagerFactory
                .createEntityManager();
        entityManager.getTransaction().begin();

        try {

            College college1 = new College();
            college1.setCollegeName("newyork");

            CollegeStudent student1 = new CollegeStudent();
            student1.setStudentName("mike");
            student1.setCollege(college1);
            entityManager.persist(student1);

            entityManager.persist(college1);

            College college2 = new College();
            college2.setCollegeName("tjzd");

            CollegeStudent student2 = new CollegeStudent();
            student2.setStudentName("tom");
            student2.setCollege(college2);
            entityManager.persist(student2);

            CollegeStudent student3 = new CollegeStudent();
            student3.setStudentName("jerry");
            student3.setCollege(college2);
            entityManager.persist(student3);

            entityManager.persist(college2);

            entityManager.getTransaction().commit();
        }
        catch (Exception e) {
            entityManager.getTransaction().rollback();
        }
    }

    @Test
    public void test02() {
        EntityManager entityManager = entityManagerFactory
                .createEntityManager();
        entityManager.getTransaction().begin();

        try {
            List<College> list = entityManager.createQuery("from College")
                    .getResultList();

            for (College college : list) {
                System.out.println(college.getCollegeName());
                for (CollegeStudent student : college.getStudents()) {
                    System.out.println("\t" + student.getStudentName());
                }
            }

            entityManager.getTransaction().commit();
        }
        catch (Exception e) {
            entityManager.getTransaction().rollback();
        }
    }
}