在Java bean中创建一个进程，获取输出并返回到Web页面

Question

Suppose I have a java bean named "Mainbean", which is used to handle a request from web page.

I want to create a process "proc" in this bean, and get the output of proc, return them to the web page asynchronously, and show them in a inputTextArea in JSF.

Since "proc" may has so many lines of output, I want to return them line by line and real-time, but not show all them after the process finished.

I used following code to create a process and try to get the output. But it seems like the process failed to exit normally, cause the exit value always be -1.

builder = new ProcessBuilder("java", "-Xms1024m","-Xmx1024m","-Xss65536k","-cp ",spaceMaker,"SmartBridge", solution," ",this.specFile,"1000000");
proc = builder.start();
InputStream is = proc.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
returnValue  = proc.waitFor();

while ((line = br.readLine()) != null) {
    // Outputs your process execution
    System.out.println(line);
    this.metaOutput = this.metaOutput.concat(line);
    exit = proc.exitValue();
    if (exit == 0) {
        // Process finished
        break;
    }
    return output;
}

And in JSF page, I use following code:

<h:form>
    <h:inputTextarea id="processOutput" value="#{mainBean.metaOutput}" cols="80" rows="20">
        <f:ajax render="processOutput"/>
    </h:inputTextarea>
 </h:form>

My question is: How can I use these technology to meet my requirement in high-level? Of course, code examples will help me definitely.

Answer 1

If you are looking for Reverse ajax kind of response. You could use PRIMEFACES PUSH reverse ajax Technology. Here is the link. PrimPush