Question

我有调度图像的问题，通过数据库中的serlvet加载。我用这个班级

public class ImageServlet extends HttpServlet {

private static final int DEFAULT_BUFFER_SIZE = 10240;

@EJB
private GoodsDAO goodsDAO;

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    String stringImageId = request.getParameter("id");

    if (stringImageId == null) {
        response.sendError(HttpServletResponse.SC_NOT_FOUND); // 404.
        return;
    }
    int imageId = Integer.parseInt(stringImageId);
    Goods goods = goodsDAO.find(imageId);

    if (goods == null) {

        response.sendError(HttpServletResponse.SC_NOT_FOUND); // 404.
        return;
    }

    response.reset();
    response.setBufferSize(DEFAULT_BUFFER_SIZE);
    response.setContentType("image/jpeg");
    response.setContentLength(goods.getImage().length);
    response.setHeader("Expires", "Thu, 15 Apr 2010 20:00:00 GMT");

    BufferedOutputStream output = null;

    try {
        output = new BufferedOutputStream(response.getOutputStream(), DEFAULT_BUFFER_SIZE);
        output.write(goods.getImage());
    } finally {
        close(output);
    }
}

private static void close(Closeable resource) {
    if (resource != null) {
        try {
            resource.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
}

my faces-config

<faces-config xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_2_0.xsd"
version="2.0">


<navigation-rule>
    <navigation-case>
        <from-outcome>listAllGoods</from-outcome>
        <to-view-id>/pages/protected/user/listAllGoods.xhtml</to-view-id>
    </navigation-case>
</navigation-rule>

<navigation-rule>
    <navigation-case>
        <from-outcome>createGoods</from-outcome>
        <to-view-id>/pages/protected/admin/createGoods.xhtml</to-view-id>
    </navigation-case>
</navigation-rule>

<navigation-rule>
    <navigation-case>
        <from-outcome>createOrder</from-outcome>
        <to-view-id>/pages/protected/user/createOrder.xhtml</to-view-id>
    </navigation-case>
</navigation-rule>

<application>
    <resource-bundle>
        <base-name>messages</base-name>
        <var>msgs</var>
    </resource-bundle>
</application>

我的web.xml

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
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>ClothesJSF</display-name>
<welcome-file-list>
    <welcome-file>pages/protected/user/listAllGoods.xhtml</welcome-file>
</welcome-file-list>
<servlet>
    <servlet-name>Faces Servlet</servlet-name>
    <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>Faces Servlet</servlet-name>
    <url-pattern>/faces/*</url-pattern>
    <url-pattern>*.jsf</url-pattern>
    <url-pattern>*.xhtml</url-pattern>
</servlet-mapping>
<servlet>
    <servlet-name>imageServlet</servlet-name>
    <servlet-class>com.servlet.ImageServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>imageServlet</servlet-name>
    <url-pattern>/image/*</url-pattern>
</servlet-mapping>
<filter>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <filter-class>org.primefaces.webapp.filter.FileUploadFilter</filter-class>
    <init-param>
        <param-name>thresholdSize</param-name>
        <param-value>51200</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <servlet-name>Faces Servlet</servlet-name>
</filter-mapping>

我使用以下代码加载我的图片：

<h:graphicImage id="zoomImage" value="image?id=#{goods.id}"
                style="cursor:pointer" width="70" />

我在非主页上显示图像时遇到问题。当我打开页面时：

http://localhost:8080/ClothesJSF/

我的所有图片通常都是从数据库加载的。如果我打开页面

http://localhost:8080/ClothesJSF/pages/protected/user/listAllGoods.xhtml

等于我的主页我的图片将不会被加载。所有其他页面也出现此问题。

我认为我的image-servlet设置存在问题

<servlet-mapping>
<servlet-name>imageServlet</servlet-name>
<url-pattern>/image/*</url-pattern>
</servlet-mapping>

也许我需要在url-pattern中使用其他正则表达式，但我无法弄明白。我会很高兴任何建议。谢谢你。

更新如果我将在所有图片中使用这样的路径：

<h:graphicImage id="zoomImage" value="http://localhost:8080/ClothesJSF/image?id=#
{goods.id}" style="cursor:pointer" width="70" />

它会工作，但如果我将使用＃{request.contextPath} /这将无效。如果我想要＃{request.contextPath} / image？id =＃就可以了，我可能需要进行一些偏好更改。

Answer 1

如果<h:graphicImage value>不是以方案或/开头，那么它与当前请求网址相关。想象一下，您正在按http://localhost:8080/ClothesJSF/faces/page.xhtml打开该页面，并且该页面有一个

<h:graphicImage value="image?id=1" />

然后JSF将生成

<img src="image?id=1" />

实际上与http://localhost:8080/ClothesJSF/faces/相关，web浏览器将尝试从http://localhost:8080/ClothesJSF/faces/image?id=1下载实际图像，因此只会出错。如果您已经注意到webbrowser的内置HTTP流量监视器，那么您已经注意到了。

您需要让它以/开头，使其相对于上下文路径。

<h:graphicImage value="/image?id=1" />

这样JSF就会生成

<img src="/ClothesJSF/image?id=1" />

哪个是对的。请注意，#{request.contextPath}不是必需的。 <h:graphicImage>已经透明地处理它。您只需要在“纯HTML”资源元素中使用它，例如<a>，<img>，<link>，<iframe>等。

JSF Image servlet不加载图像

1 个答案: