Re: How to display (browser) images (inputstream) from the server?

Typically you would read URLs through DWR and use _javascript_ to generate img nodes to display the URLs. Basically the download of the binary data is done by the browser. If you do want to return through DWR the binary data that makes up the images you can add it as members in your class/objects. I do not know how/if DWR will serialize the data and how you will process it on the _javascript_ side.

-- 

Marius Seritan

marius-ALVOsWIOdiJWk0Htik3J/w@xxxxxxxxxxxxxxxx

On Feb 26, 2007, at 9:57 AM, Rickardsson Daniel wrote:

Hi!

 

How can I display images that is being read from a server?!

 

I want to read many images and therfore using dwr.

 

In my ajax-java-method I use:

WebContext ctx = WebContextFactory.get();
HttpServletRequest request = ctx.getHttpServletRequest();
HttpServletResponse response = ctx.getHttpServletResponse();

 

//then gets the outputstream

ServletOutputStream out = response.getOutputStream();

 

//writes my picture (inputstream) to my outputstream

StreamUtils.copyStream(is, out);

 

And on client side I have the following:

document.getElementById('map').style.backgroundImage = MapClass.getMap(<parameters>);

 

No picture is shown and my log says:

2007-02-26 18:02:57,528 ERROR [http-8080-1] org.apache.catalina.core.StandardWrapperValve.invoke() Servlet.service() for servlet myApplication threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
 at org.apache.catalina.connector.Response.getWriter(Response.java:599)
 at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:195)
 at uk.ltd.getahead.dwr.impl.DefaultExecProcessor.handle(DefaultExecProcessor.java:157)
 at uk.ltd.getahead.dwr.impl.DefaultProcessor.handle(DefaultProcessor.java:81)
 at uk.ltd.getahead.dwr.AbstractDWRServlet.doPost(AbstractDWRServlet.java:162)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
 at org.springframework.web.servlet.mvc.ServletWrappingController.handleRequestInternal(ServletWrappingController.java:174)
 at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153)
 at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:45)
 at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:806)
 at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:736)
 at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:396)
 at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:360)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
 at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:833)
 at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:639)
 at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1285)
 at java.lang.Thread.run(Unknown Source)

 

Does anyone have any idea what to do?!

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