我正在尝试显示客户图像（存储CustomerMaster.customerPhoto在 BLOB 对象中）。我正在使用 imageBuilder Bean (RequestScoped) 根据存储CustomerMaster在 Customer Bean(ViewScoped) 中可用的内容来构造图像。我在 ImageBuilder 中添加了属性来访问客户 Bean 中的 CustomerMaster 对象。还添加了用于跟踪目的的 sysout 语句。
这是输出
09:34:22,817 INFO [stdout] (http--127.0.0.1-8080-2) getImage - 1
09:34:22,817 INFO [stdout] (http--127.0.0.1-8080-2) getImage - 3
09:34:22,817 INFO [stdout] (http--127.0.0.1-8080-2) getImage - 4
09:34:22,817 INFO [stdout] (http--127.0.0.1-8080-2) getImage - 5PhotoMaster [photoId=1, contentType=image/gif] 2064
09:34:22,817 INFO [stdout] (http--127.0.0.1-8080-2) getImage - 6
09:34:22,827 WARNING [javax.enterprise.resource.webcontainer.jsf.context] (http--127.0.0.1-8080-2) JSF1091: No mime type could be found for file dynamiccontent. To resolve this, add a mime-type mapping to the applications web.xml.
09:34:23,057 SEVERE [org.primefaces.application.PrimeResourceHandler] (http--127.0.0.1-8080-4) Error in streaming dynamic resource. Unable to set property customerBean for managed bean imageBuilderBean
基于 sysout 语句，我可以看到 ImageBuilderBean 能够访问 CustomerMaster 对象并能够创建 DefaultStreamedContent。
但后来我收到以下严重消息，并且网页上没有显示图像：
09:34:23,057 SEVERE [org.primefaces.application.PrimeResourceHandler] (http--127.0.0.1-8080-4) Error in streaming dynamic resource. Unable to set property customerBean for managed bean imageBuilderBean
如果我在 CustomerBean 中使用 Session 范围（而不是 ViewScoped），那么一切都是工作文件。甚至图像也显示在网页上。根据我的理解，从 requestScoped Bean 调用 Viewscoped bean 应该没有任何问题。
我不确定出了什么问题。请帮忙。请参阅代码以供参考。
ImageBuilder.Java
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.Serializable;
import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import javax.faces.bean.RequestScoped;
import javax.faces.context.FacesContext;
import org.primefaces.model.DefaultStreamedContent;
import org.primefaces.model.StreamedContent;
@ManagedBean (name="imageBuilderBean")
@RequestScoped
public class ImageBuilderBean implements Serializable {
private static final long serialVersionUID = -480089903900643650L;
@ManagedProperty(value="#{customerBean}")
private CustomerBean customerBean;
private StreamedContent image;
public ImageBuilderBean() {
super();
}
@PostConstruct
void ResetBean(){
System.out.println("getImage - 1");
FacesContext context = FacesContext.getCurrentInstance();
if (context.getRenderResponse()) {
System.out.println("getImage - 2");
// So, we're rendering the view. Return a stub StreamedContent so that it will generate right URL.
image = new DefaultStreamedContent();
}
else {
System.out.println("getImage - 3");
CustomerMaster custMaster = customerBean.getCustMaster();
if (custMaster != null){
System.out.println("getImage - 4");
PhotoMaster photo = custMaster.getCustomerPhoto();
if (photo != null) {
try {
System.out.println("getImage - 5" + photo + " " + photo.getContent().length());
InputStream inputStream = photo.getContent().getBinaryStream();
image = new DefaultStreamedContent(inputStream, photo.getContentType());
System.out.println("getImage - 6");
} catch (Exception e) {
// TODO Auto-generated catch block
System.out.println("exception Shirish");
e.printStackTrace();
}
}
}
}
}
客户.XHTML
<p:column>
<p:graphicImage id="custImageId" value="#{imageBuilderBean.image}" cache="false" />
</p:column>
CustomerBean.Java
import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import javax.faces.bean.ViewScoped;
@ManagedBean (name="customerBean")
@ViewScoped
public class CustomerBean implements Serializable {
private static final long serialVersionUID = -3727342589028832013L;
// Setters and Getters
更新：
由于graphicImage标签被转换为<img>html标签。浏览器生成两个显示图像的请求。生成以下两个网址：
/proj/views/user/CustomerRegistration.xhtml- ManagedProperty 注释返回 viewscoped customerBeans。/proj/javax.faces.resource/dynamiccontent.xhtml- 未能返回 customerBean。因此，我们看到“无法为托管 bean imageBuilderBean 设置属性 customerBean”错误消息
有什么建议么？