Question

我只想在JSF中检索结果列表。

我的JSF文件：

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:h="http://java.sun.com/jsf/html">

<h:head>
    <h:outputStylesheet library="css" name="css/style.css" />
    <f:facet name="">
    <meta http-equiv="content-type" content="text/html"/>
    </f:facet>
</h:head>
<body>
    <h:form>
        <h:inputText value="#{CarBean.carName}" />
        <h:commandButton type="submit" action="#{CarBean.result()}"
            value="Set Name" />
    </h:form>
    <a id="InformationInputText" href="information.xhtml">Get Info</a>
    <h1 id="InformationInputText">Car list:</h1>
    <h:dataTable value="#{CarBean.list}" var="car">
        <h:column>${car}</h:column>
    </h:dataTable>
</body>
</html>

我的bean文件：

import java.util.List;

import javax.enterprise.context.RequestScoped;
import javax.faces.bean.ManagedBean;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.Query;

@ManagedBean
@RequestScoped
public class CarBean {

    public CarBean() {

    }

    // Variables
    public String carName = "";
    public List<?> list;
    public static final String PERSISTENCE_UNIT_NAME = "CarApp";

    // Methods
    public void setCarName(String carName) {
        this.carName = carName;
    }

    public String getCarName() {
        return carName;
    }

    public String setName() {

        return carName;
    }

    public List<?> getList() {
        return list;
    }

    public void setList(List<?> list) {
        this.list = list;
    }
    // Get result from database by select
    public List<?>result() {
        EntityManagerFactory factory = Persistence
                .createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
        EntityManager em = factory.createEntityManager();
        Query query = em
                .createNativeQuery("SELECT carName,company,fuelInLitre FROM car");
        list = query.getResultList();

        return list;
    }
}

的web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0">
    <display-name>CarApp</display-name>
    <servlet>
        <servlet-name>FacesServlet</servlet-name>
        <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>FacesServlet</servlet-name>
        <url-pattern>/faces/*</url-pattern>
    </servlet-mapping>
    <context-param>
        <description>State saving method: 'client' or 'server' (=default). See JSF Specification 2.5.2</description>
        <param-name>javax.faces.STATE_SAVING_METHOD</param-name>
        <param-value>client</param-value>
    </context-param>
    <context-param>
        <param-name>javax.servlet.jsp.jstl.fmt.localizationContext</param-name>
        <param-value>resources.application</param-value>
    </context-param>
    <listener>
        <listener-class>com.sun.faces.config.ConfigureListener</listener-class>
    </listener>
    <mime-mapping>
        <extension>html htm</extension>
        <mime-type>text/html</mime-type>
    </mime-mapping>
    <mime-mapping>
        <extension>txt</extension>
        <mime-type>text/plain</mime-type>
    </mime-mapping>
    <mime-mapping>
        <extension>css</extension>
        <mime-type>text/css</mime-type>
    </mime-mapping>
    <mime-mapping>
        <extension></extension>
        <mime-type>application/octet-stream</mime-type>
    </mime-mapping>
</web-app>

我收到了警告

WARNING: JSF1091: No mime type could be found for file /[[Ljava.lang.Object;@6084721c, [Ljava.lang.Object;@3efe6c9e, [Ljava.lang.Object;@5c18c2c, [Ljava.lang.Object;@24f8ca75, [Ljava.lang.Object;@672f5864].  To resolve this, add a mime-type mapping to the applications web.xml.

我的JSF文件的输出：

Car list:

[Ljava.lang.Object;@3e53d993
[Ljava.lang.Object;@50c3ef5d
[Ljava.lang.Object;@34f6502e
[Ljava.lang.Object;@1c9c1393
[Ljava.lang.Object;@3c23ced2

问题出在哪里？我应该添加到我的web.xml中？我想说一件事。当我写下这样的东西时：

<h:dataTable value="#{CarBean.list.get(0)}" var="car">
        <h:column>${car}</h:column>
    </h:dataTable>

获取元素0的结果没有问题。

Answer 1

问题是List<?>填充了Object[]，并且使用#{car} JSF使用toString方法作为数组。最好的选择是返回List<YourClass> YourClass实施toString方法而不是List<?>。

警告：JSF1091：找不到文件的mime类型

1 个答案: