Problema hibernate

org.hibernate.QueryException: could not resolve property: login of: vo.UsuarioVO [from vo.UsuarioVO as user where user.login = 'adm']
        at org.hibernate.persister.entity.AbstractPropertyMapping.propertyException(AbstractPropertyMapping.java:44)
        at org.hibernate.persister.entity.AbstractPropertyMapping.toType(AbstractPropertyMapping.java:38)
        at org.hibernate.persister.entity.AbstractEntityPersister.toType(AbstractEntityPersister.java:1358)
        at org.hibernate.hql.ast.tree.FromElementType.getPropertyType(FromElementType.java:279)
        at org.hibernate.hql.ast.tree.FromElement.getPropertyType(FromElement.java:386)
        at org.hibernate.hql.ast.tree.DotNode.getDataType(DotNode.java:566)
        at org.hibernate.hql.ast.tree.DotNode.prepareLhs(DotNode.java:241)
        at org.hibernate.hql.ast.tree.DotNode.resolve(DotNode.java:188)
        at org.hibernate.hql.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:94)
        at org.hibernate.hql.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:90)
        at org.hibernate.hql.ast.HqlSqlWalker.resolve(HqlSqlWalker.java:728)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.expr(HqlSqlBaseWalker.java:1216)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.exprOrSubquery(HqlSqlBaseWalker.java:4041)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.comparisonExpr(HqlSqlBaseWalker.java:3525)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.logicalExpr(HqlSqlBaseWalker.java:1762)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.whereClause(HqlSqlBaseWalker.java:776)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:577)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:281)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:229)

...

<?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>  
        <property name="hibernate.cglib.use_reflection_optimizer">false</property>
        <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
        <property name="hibernate.connection.url">jdbc:postgresql://localhost:5432/cadastro</property>
        <property name="hibernate.connection.username">postgres</property>        
        <property name="hibernate.connection.password">123456</property>         
        <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="show_sql">true</property>
        <property name="hibernate.generate_statistics">true</property>
        <property name="hibernate.use_sql_comments">true</property>        
        <mapping class="vo.UsuarioVO"/>
       
    </session-factory>
</hibernate-configuration>

package vo;

/**
 *
 * @author joaosavio
 */
import javax.persistence.*;

@Entity
public class UsuarioVO implements java.io.Serializable {
    @Id
    @GeneratedValue
    private int id;
    private String usuario;
    private String senha;

    public int getId() {
        return id;
    }

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

    public String getUsuario() {
        return usuario;
    }

    public void setUsuario(String usuario) {
        this.usuario = usuario;
    }

    public String getSenha() {
        return senha;
    }

    public void setSenha(String senha) {
        this.senha = senha;
    }

}

public UsuarioVO checarLogin(String login) throws HibernateException 
    {
        try 
        {
            DAOFactory dao = new DAOFactory();
            dao.beginTransaction();
            String hql = "from UsuarioVO as user where user.login = '"+login+"'";
            session = HibernateUtil.getSession();
            Query q = session.createQuery(hql);
            usuarioVO = (UsuarioVO) q.uniqueResult();
            dao.commit();
            dao.close();
            return usuarioVO;
        }
        catch (Exception e) 
        {
            e.printStackTrace();
            return null;
        }
    }