<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"><hibernate-configuration><session-factory><!-- Database connection settings --><property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property><property name="connection.url">jdbc:oracle:thin:@localhost:1521:orcl</property><property name="connection.username">system</property><property name="connection.password">orcl</property><!-- JDBC connection pool (use the built-in) --><property name="connection.pool_size">2</property><!-- SQL dialect --><property name="dialect">org.hibernate.dialect.Oracle9Dialect</property><!-- Echo all executed SQL to stdout --><property name="show_sql">true</property><property name="hbm2ddl.auto">create</property><property name="current_session_context_class">thread</property>  <mapping resource="com/demo/manyToMany/Project.hbm.xml"/><mapping resource="com/demo/manyToMany/Employee.hbm.xml"/></session-factory></hibernate-configuration>

package com.demo.manyToMany;import java.util.HashSet;
import java.util.Set;public class Employee {public Employee(){}public Employee(int id, String name, Set<Project> projects) {super();this.id = id;this.name = name;this.projects = projects;}private int id;private String name;private Set<Project> projects = new HashSet<Project>();public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Set<Project> getProjects() {return projects;}public void setProjects(Set<Project> projects) {this.projects = projects;}
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mappingpackage="com.demo.manyToMany"><class name="Employee" table="Employee"><id name="id"><generator class="sequence"><param name="sequence">seq_projectSys_employee</param></generator></id><property name="name"/><set name="projects" table="EmployeeProject" inverse="true"><key column="employee_id" /><many-to-many class="Project" column="project_id" /></set></class></hibernate-mapping>

package com.demo.manyToMany;import java.util.HashSet;
import java.util.Set;public class Project {public Project(){}public Project(int id, String name, Set<Employee> employees) {super();this.id = id;this.name = name;this.employees = employees;}private int id;private String name;private Set<Employee> employees = new HashSet<Employee>();public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Set<Employee> getEmployees() {return employees;}public void setEmployees(Set<Employee> employees) {this.employees = employees;}}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mappingpackage="com.demo.manyToMany"><class name="Project" table="Project"><id name="id"><generator class="sequence"><param name="sequence">seq_projectSys_project</param></generator></id><property name="name"/><set name="employees" table="EmployeeProject"><key column="project_id" /><many-to-many class="Employee" column="employee_id" /></set></class></hibernate-mapping>