Question

I am looking to pass a string from my Java to a javascript showContent function. Both the Java and javascript are contained in a JSP page. The string strLine contains XML content I want to display using the showContent function.

My Java

        try{    
        //Open the file that is the first command line parameter
            FileInputStream fstream = new FileInputStream(table.get(xmlMatch));                 

            // Get the object of DataInputStream
            DataInputStream in = new DataInputStream(fstream);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String strLine;

        //Read File Line By Line
            while ((strLine = br.readLine()) != null)   
            {
                out.println (strLine);
            }  

The Javascript (I have to credit Peter for supplying me with this in another question)

<script type="text/javascript" language="JavaScript">
function showContent()
{
document.getElementById('showContent').innerHTML = "printed content";
}
</script>

I have tried replacing the above “printed content” with "strLine"; (strLine); and ("strLine");

I also tried set strLine as a session attribute using
session.setAttribute("strLine", strLine); and using "<%=strLine%>"; but the result was null printed to the screen.

Any help with this would be great.

The HTML

<a href="#" onclick="showContent()">Next! <%=keywords%> concept </a>
<div id="showContent"></div>

Answer 1

Instead of printing it with out.println, you should put in a variable (a StringBuilder maybe). In order to do that you have to:

Declare the variable at the right scope (maybe at the beginning of the JSP)

StringBuilder contentInnerHtml = new StringBuilder();

Then append the text of the file to this new variable:

while ((strLine = br.readLine()) != null)   
{
    contentInnerHtml.append(strLine);
}

Finally, in the javascript part of the code return its value (with toString()):

<script type="text/javascript" language="JavaScript">
function showContent()
{
    document.getElementById('showContent').innerHTML = "<%=contentInnerHtml.toString()%>";
}
</script>