Spring - 在jsp文件上显示图像 [英] Spring - display image on jsp file

问题描述

我的模型存储图像用文件名(作为字符串)和数据(作为字节数组)描述.我使用 Hibernate，这是我的模型:

my model store image described with file name (as String) and data (as byte array). I use Hibernate and here's my model:

@Entity
public class Image {

    private Long id;
    private String name;
    private byte[] data;

    @Id
    @GeneratedValue
    @Column(name = "IMAGE_ID")
    public Long getId() {
        return id;
    }

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

    @Column(nullable = false, length = 100)
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Lob
    @Column(nullable = false)
    public byte[] getData() {
        return data;
    }

    public void setData(byte[] data) {
        this.data = data;
    }
}

但我想在网站上显示我存储的图像:

But I want to display my stored image, on web site like:

<img src="${image.data}" alt="car_image"/>

我怎么能这样做?

我应该编写处理图像请求的控制器吗?

Should I write controller that serve requests for images?

任何代码示例?

更新

<bean id="viewResolver"
    class="org.springframework.web.servlet.view.UrlBasedViewResolver">
    <property name="viewClass"
        value="org.springframework.web.servlet.view.tiles2.TilesView" />
</bean>

<bean id="tilesConfigurer"
    class="org.springframework.web.servlet.view.tiles2.TilesConfigurer">
    <property name="definitions">
        <list>
            <value>/WEB-INF/configs/tiles.xml</value>
        </list>
    </property>
</bean>

推荐答案

你不能这样做.您的图像必须通过普通 URL 以某种方式公开.在 Spring MVC 中创建一个控制器，在特定 URL 下返回图像(原始数据):

You cannot do it like this. Your image must be exposed somehow via normal URL. In Spring MVC create a controller that returns an image (raw data) under particular URL:

@RequestMapping(value = "/imageController/{imageId}")
@ResponseBody
public byte[] helloWorld(@PathVariable long imageId)  {
  Image image = //obtain Image instance by id somehow from DAO/Hibernate
  return image.getData();
}

现在在您的 JSP 页面中使用它.这是 HTTP/HTML 的工作方式:

Now useit in your JSP page. This is how HTTP/HTML work:

<img src="/yourApp/imageController/42.png" alt="car_image"/>

在 3.1 之前的 Spring MVC 中，您可能需要在控制器端做更多的编码.但是原理是一样的.

In Spring MVC before 3.1 you might need to do a little bit more coding on controller side. But the principle is the same.

这篇关于Spring - 在jsp文件上显示图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！