Question

我有一个NamedQuery，由于某种原因，它返回null。语法似乎有效：

 @NamedQuery(name="Usuario.userLogin", query = "SELECT u.email, u.senha FROM Usuario u WHERE u.email = :mail AND u.senha = :senha")

使用MD5对密码进行哈希处理。（出于安全原因无用，但不是问题的重点）。

这是验证哈希的位置，然后在登录有效时重定向。

  response.setContentType("text/html;charset=UTF-8");
    PrintWriter pw = response.getWriter();
    String mail = request.getParameter("mail");        
    String senha = request.getParameter("senha");
    try {
        senha = ControllerUsuario.criptografa(senha);
    } catch (NoSuchAlgorithmException ex) {
        Logger.getLogger(CadastroUsuario.class.getName()).log(Level.SEVERE, null, ex);
    }
    Usuario user = ControllerUsuario.getSenha(mail, senha);
    if (user != null) {
        HttpSession session = request.getSession();
        pw.println("Tipo: " + user.getEmail());
        session.setAttribute("mail", user.getEmail());
        session.setAttribute("tipo_usr", user.getTipo_usr());
        session.setAttribute("usr", user.getUsuario());
        session.setAttribute("logado", 1);
      //  response.sendRedirect("index");
    } else {
        response.sendRedirect("cadastro-falha.html");
    } 
}

这是验证用户和密码的地方。但是，这总是返回null属性。

  public static Usuario getSenha(String mail, String senha) {
    SessionFactory sf = HibernateUtil.getSessionFactory();
    Session session = null;
    Transaction tx = null;
    Usuario user = new Usuario();
    try {
        session = sf.openSession();
        tx = session.getTransaction();
        tx.begin();
        Query query = session.getNamedQuery("Usuario.userLogin");
        query.setParameter("mail", mail);
        query.setParameter("senha", senha);
        user = (Usuario) query.uniqueResult();
        tx.commit();
    } catch (Exception e) {
        if (tx != null) tx.rollback();
    } finally {
        session.close();
    }
    return user;
}

堆栈追踪：

Grave:   java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to org.coursera.Model.Usuario
at org.coursera.Controller.ControllerUsuario.getSenha(ControllerUsuario.java:67)
at org.coursera.View.Login.processRequest(Login.java:32)
at org.coursera.View.Login.doPost(Login.java:72)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)
Advertência:   StandardWrapperValve[Index]: Servlet.service() for servlet Index threw exception
java.lang.NullPointerException
at org.coursera.View.Index.processRequest(Index.java:50)
at org.coursera.View.Index.doGet(Index.java:103)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)

怎么了？

Answer 1

我不确定这是原因，但在休眠时你不需要＆＃39; 选择＆＃39;关键词。所以：

 @NamedQuery(name="Usuario.userLogin", query = "u.email, u.senha FROM Usuario u WHERE u.email = :mail AND u.senha = :senha"

你也希望看到异常：

} catch (Exception e) {
        e.printStackTrace(); <--here logging or etc..
        if (tx != null) tx.rollback();
    } finally {
        session.close();
    }

编辑：您也试图在这里选择Usuario的字段：

u.email, u.senha FROM Usuario u

但是试图将这些字段转换为Usuario对象：

user = (Usuario) query.uniqueResult();

在这种情况下你也可以摆脱字段： @NamedQuery（name =＆＃34; Usuario.userLogin＆＃34;，query =＆＃34; FROM Usuario u WHERE u.email =：mail AND u.senha =：senha＆＃34;

Answer 2

问题可能出在您的演员user = (Usuario) query.uniqueResult();中，因为您选择了两个项目，而不是整个Usuario。

只需将e.printStackTrace()添加到您的catch子句中，您就会看到真正的原因。

getNamedQuery返回null

2 个答案: