Streaming content to JSF UI
- by Mark Lewis
Hello,
I was quite happy with my JSF app which read the contents of MQ messages received and supplied them to the UI like this:
<rich:panel>
<snip>
<rich:panelMenuItem label="mylabel" action="#{MyBacking.updateCurrent}">
<f:param name="current" value="mylog.log" />
</rich:panelMenuItem>
</snip>
</rich:panel>
<rich:panel>
<a4j:outputPanel ajaxRendered="true">
<rich:insert content="#{MyBacking.log}" highlight="groovy" />
</a4j:outputPanel>
</rich:panel>
and in MyBacking.java
private String logFile = null;
...
public String updateCurrent() {
FacesContext context=FacesContext.getCurrentInstance();
setCurrent((String)context.getExternalContext().getRequestParameterMap().get("current"));
setLog(getCurrent());
return null;
}
public void setLog(String log) {
sendMsg(log);
msgBody = receiveMsg(moreargs);
logFile = msgBody;
}
public String getLog() {
return logFile;
}
until the contents of one of the messages was too big and tomcat fell over. Obviously, I thought, I need to change the way it works so that I return some form of stream so that no one object grows so big that the container dies and the content returned by successive messages is streamed to the UI as it comes in.
Am I right in thinking that I can replace the work I'm doing now on a String object with a BufferedOutputStream object ie no change to the JSF code and something like this changing at the back end:
private BufferedOutputStream logFile = null;
public void setLog(String log) {
sendMsg(args);
logFile = (BufferedOutputStream) receiveMsg(moreargs);
}
public String getLog() {
return logFile;
}
