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POHibernate saves a new object with every merge
 

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    <p>I am having a peculiar problem. Every time,I call merge, on the session, Hibernate persists a brand new object. I am using Hibernate 3.6 in a Spring MVC application.</p> <p>Please find below my code:</p> <p><strong>My hibernate.cfg.xml</strong></p> <pre><code>&lt;hibernate-configuration&gt; &lt;session-factory&gt; &lt;property name="dialect"&gt;org.hibernate.dialect.Oracle10gDialect &lt;/property&gt; &lt;!-- this will show us all sql statements --&gt; &lt;property name="hibernate.show_sql"&gt; true &lt;/property&gt; &lt;property name="connection.pool_size"&gt;1&lt;/property&gt; &lt;!-- &lt;property name="hbm2ddl.auto"&gt;create&lt;/property&gt;--&gt; &lt;!-- mapping files --&gt; &lt;mapping resource="com/hibernate/hbm/employee.hbm.xml"&gt;&lt;/mapping&gt; &lt;/session-factory&gt; &lt;/hibernate-configuration&gt; </code></pre> <p>My <strong>employee.hbm.xml</strong></p> <pre><code>&lt;hibernate-mapping default-lazy="true"&gt; &lt;class name="com.spring.model.Employee" table="employee"&gt; &lt;id name="empId" type="long" column="empId" unsaved-value="null"&gt; &lt;generator class="sequence"&gt; &lt;param name="sequence"&gt;hibernate_sequence&lt;/param&gt; &lt;/generator&gt; &lt;/id&gt; &lt;version name="version" column="version" unsaved-value="null" type="long" /&gt; &lt;component name="identity" class="com.spring.model.Identity"&gt; &lt;property name="firstname" column="firstname" not-null="true" /&gt; &lt;property name="lastname" column="lastname" not-null="true" /&gt; &lt;property name="email" column="emailid" not-null="true" /&gt; &lt;/component&gt; &lt;!-- &lt;property name="birthday" column="birthday"/&gt; --&gt; &lt;property name="fileDataBytes" column="filedata" /&gt; &lt;property name="fileName" column="fileName" /&gt; &lt;property name="fileContentType" column="fileContentType" /&gt; &lt;/class&gt; &lt;/hibernate-mapping&gt; </code></pre> <p>My <strong>model classes</strong></p> <pre><code> public class Employee extends BaseModel{ private CommonsMultipartFile fileData; private byte[] fileDataBytes; private String fileName; private String fileContentType; private Identity identity; private long empId; //getters,setters /equals() on empId field @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + (int) (empId ^ (empId &gt;&gt;&gt; 32)); return result; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; Employee other = (Employee) obj; if (empId != other.empId) return false; return true; } public class BaseModel implements Serializable{ private Long version; //gettes,setters public class Identity { protected String firstname; protected String lastname; protected String email; //getters.setters </code></pre> <p>My <strong>employeeDAOImpl.java's save</strong> method</p> <pre><code>public long saveEmployee(Employee employee) throws Exception { public Employee getEmployeeById(long empId) { // TODO Auto-generated method stub return (Employee) getSessionFactory().getCurrentSession().load(Employee.class,empId); } } // TODO Auto-generated method stub if(employee.getEmpId() == 0){ return (Long)getSessionFactory().getCurrentSession().save(employee); }else{ Employee empInSession = getEmployeeById(employee.getEmpId()); getSessionFactory().getCurrentSession().merge(employee); return employee.getEmpId(); } } </code></pre> <p>Note : i already had loaded the object in the GET cycle , but to ensure that the object is loaded in the cache, I am still loading it before the call to merge().Ideally, the merge shouldn't be required at all,as the object becomes persistent. Why the hell does this happen? Hibernate saves a new object with the changed properties and saves it. Shouldn't it check via the empId field which is in the equals check??</p>
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