Tapestry 显示图片

导入的blog格式乱了，请看我的msn spaces blog：http://dengyin2000.spaces.live.com/blog/cns!AF4AB52B167D7EE7!166.entry
what you&aposre doing is trying to use a @Insert component to insert a blobin your page. It will never work like that since Tapestry will actually tryto display the string representation of your blob (if you callpersonImage.toString() you&aposll get exactly that "oracle.sql.BLOB@1176e8a").You need something a bit more sophisticated. I&aposve done exactly what you&aposretrying to do so I&aposll explain it to you. I won&apost past all my code since it&apossvery application-specific.First you need to create a service that will produce the image contents, socreate a class for that. Something like this:public class ImageService implements IEngineService {   public ILink getLink(boolean isPost, Object parameters) {      Object personId = parameterArray[0];      Map serviceParameters = new HashMap();      serviceParameters.put(ServiceConstants.SERVICE, getName());      serviceParameters.put(ServiceConstants.PARAMETER, new Object[] {personId });      return linkFactory.constructLink(this, isPost, serviceParameters,true);   }    public String getName() {        return "personImage";    }   public void service(IRequestCycle cycle) throws IOException {      // here you have to set the appropriate content type      // I&aposm assuming it&aposs a jpeg image.      ContentType contentType = new ContentType("image/jpeg");      OutputStream outputStream = webResponse.getOutputStream(contentType);      Object[] parameters = linkFactory.extractListenerParameters(cycle);      Integer personId = (Integer) parameters[0];  // you have the ID, so here you do whatever you have to do      // to fetch the person object      Person person = whatever...      // then you have to write the image contents to the output stream.      int length = person.personImage.length();      outputStream.write(person.personImage.getBytes(0,length));      outputStream.close();   }}On the html page you&aposll have to use an img tag with the source being theservice you just created:On the component&aposs java class you&aposll need something like:// This is the hivemind service being injected@InjectObject("service:ImageService")public abstract IEngineService getProductImageService();public String getImageLink() {    Object[] parameters = new Object[1];    // I&aposm assuming there is a "person" variable in page    // with the person object you want to display.    parameters[0] = person.personID;    return getProductImageService().getLink(false,parameters).getAbsoluteURL();    }... next you&aposll also have to tell hivemind about the service in yourhivemodule.xml<service-point id="ImageService" interface="org.apache.tapestry.engine.IEngineService">   <invoke-factory>      <construct class="my.package.ImageService">         <set-object property="linkFactory" value="infrastructure:linkFactory">      </set-object>   </construct></invoke-factory>  <contribution configuration-id="tapestry.services.FactoryServices">   <service name="personImage" object="service:ImageService"></service>That&aposs more or less how I did it. I think that&aposs about it, but if I forgotanything I guess the docs can fill in.Denis</contribution></service-point>