java - 在 JPA 中使用两个或多个参数的搜索查询

Question

我对 Hibernate/JPA 世界还是个新手，我被困在这里试图以与按 id 搜索相同的方式创建一个函数，但我正在尝试使用两个参数从数据库中搜索并返回字段，我也用基本的 CRUD 操作加上这个特殊的操作对我的项目做了一种 DAO 方法。在进行搜索时，它给了我这个返回堆栈跟踪:

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Provided id of the wrong type for class com.exemplo.model.Pedido. Expected: class java.lang.Long, got class java.sql.Date
	at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1135)
	at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1068)
	at com.exemplo.repositorio.MySQLPedidoDAO.pesquisarPorData(MySQLPedidoDAO.java:82)
	at com.exemplo.view.ViewPedidos.btBuscarActionPerformed(ViewPedidos.java:322)
	at com.exemplo.view.ViewPedidos.access$000(ViewPedidos.java:23)
	at com.exemplo.view.ViewPedidos$1.actionPerformed(ViewPedidos.java:106)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
	at java.awt.Component.processMouseEvent(Component.java:6533)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
	at java.awt.Component.processEvent(Component.java:6298)
	at java.awt.Container.processEvent(Container.java:2236)
	at java.awt.Component.dispatchEventImpl(Component.java:4889)
	at java.awt.Container.dispatchEventImpl(Container.java:2294)
	at java.awt.Component.dispatchEvent(Component.java:4711)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
	at java.awt.Container.dispatchEventImpl(Container.java:2280)
	at java.awt.Window.dispatchEventImpl(Window.java:2746)
	at java.awt.Component.dispatchEvent(Component.java:4711)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.awt.EventQueue$3.run(EventQueue.java:703)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
	at java.awt.EventQueue$4.run(EventQueue.java:731)
	at java.awt.EventQueue$4.run(EventQueue.java:729)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
Caused by: org.hibernate.TypeMismatchException: Provided id of the wrong type for class com.exemplo.model.Pedido. Expected: class java.lang.Long, got class java.sql.Date
	at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:133)
	at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1066)
	at org.hibernate.internal.SessionImpl.access$2000(SessionImpl.java:176)
	at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.load(SessionImpl.java:2540)
	at org.hibernate.internal.SessionImpl.get(SessionImpl.java:951)
	at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1110)
	... 41 more

我的方法是这样的，DAO类:

public interface DAO <T, K> {

    public void inserir(T o);
    
    public void alterar(T o);

    public void excluir(T o);

    public T pesquisar(K id);

    public List<T> listar();
    
}

PedidoDAO:

public interface PedidoDAO extends DAO <Pedido, Long> {
    
    public Pedido pesquisarPorData(Date dataCadastro);
    
}

MySQLPedidoDAO:(PesquisarPorData 函数出错)

public class MySQLPedidoDAO implements PedidoDAO {

    public ConnectionFactory cf = null;

    public MySQLPedidoDAO(ConnectionFactory cf) {
        this.cf = cf;
    }
    
    @Override
    public Pedido pesquisar(Long id) {
        cf.createEm().getTransaction().begin();
        Pedido pedido = cf.createEm().find(Pedido.class, id);
        cf.createEm().getTransaction().commit();
        //erro ao deletar pois o factory já está fechado
        //emf.close();
        return pedido;
    }
    
    @Override
    public Pedido pesquisarPorData(Date dataCadastro) {
        cf.createEm().getTransaction().begin();
        // ERROR AT THE LINE UNDER!!!!!
        Pedido pedido = cf.createEm().find(Pedido.class, dataCadastro);
        cf.createEm().getTransaction().commit();
        //erro ao deletar pois o factory já está fechado
        //emf.close();
        return pedido;
    }
    
}

查看Pedidos:

public class ViewPedidos extends javax.swing.JInternalFrame {

    private MySQLPedidoDAO mspdao;
    private Pedido ped;
    private boolean editavel;
    
    /* Getters e Setters from editavel and ped  */
    
    private void btPesquisaActionPerformed(java.awt.event.ActionEvent evt) {                                           
        habilitarApenasOSeData();
        limparCampos();
        tfPedido.setEditable(true);
        tfPedido.requestFocus();
        btBuscar.setEnabled(true);
    } 
    
    
    
    private void btBuscarActionPerformed(java.awt.event.ActionEvent evt) {                                         
        ConnectionFactory cf = new ConnectionFactory();
        MySQLPedidoDAO mspdao = new MySQLPedidoDAO(cf);
        Pedido ped = new Pedido();
        
        if(tfPedido.getText().length() == 0  &&  tfDataCad.getText().length() == 0){
             JOptionPane.showMessageDialog(rootPane, "Search not succeed, please fill the fields above", "Search", JOptionPane.INFORMATION_MESSAGE);
        } else {
             ped = mspdao.pesquisar(Long.parseLong(tfPedido.getText()));
             ped = mspdao.pesquisarPorData(new java.sql.Date(((java.util.Date)tfDataCad.getValue()).getTime()));
             setPed(ped);
             setEditable(true);
             carregarCampos();
             habilitarTextFieldEBotoes();
        }
              
    }   
    
    
} 

我已经测试过注释涉及日期字段的代码，只允许搜索 id，并且运行得很好，我尝试做一个快速修复来搜索 id 并注册日期，执行上述两种不同的方法，我尝试执行 createQuery 但没有任何反应，我想知道我哪里做错了？或使用两个或更多参数在 JPA 中创建搜索功能的任何提示？ (观察:我的代码是葡萄牙语，因为它是一个巴西项目，对于它或任何错误感到抱歉)并提前致谢!!

Answer 1

问题在于 EntityManager#find 要求您提供实体的主键(Long)。如果您想使用其他字段进行查询，则需要使用createQuery。

您尚未在问题中提供实体定义。但是查询将类似于:

TypedQuery<Pedido> query = cf.createEm().createQuery("id = :id and registerDate = :date", Pedido.class);
query.setParameter("date", dataCadastro);
query.setParameter("id", id);
List<Pedido> results = query.getResultList();

如果您只需要一个结果，您可以调用 query.getSingleResult() 而不是 getResultList()。如果没有单个结果，这将抛出 NonUniqueResultException。