Cannot find symbol error

Question

Let me first apologize. I've been coding for a long time now, but I'm new to Java. I feel like this should be a simple error, but I've been working on it for a half hour to no avail:

public String getHtml(HttpServletRequest request) {
    try {
        WebPageFetcher fetcher = new WebPageFetcher("http://google.com");
    } catch (Exception e) {
        log.error("WebPageFetcher failed ...");
    }

    return "<div id=\"header\">" + fetcher.getPageContent() + "</div>";
}

Where WebPageFetcher is implemented as shown here: http://www.javapractices.com/topic/TopicAction.do?Id=147

I'm getting an error:

cannot find symbol
symbol  : variable fetcher
location: class myclass

What am I doing wrong?

score 5 · Accepted Answer · answered Feb 09 '11 at 23:42

5

fetcher is visible only in the block where it was declared, the try block. Try declaring before the block so it will be visible throughout the method:

WebPageFetcher fetcher = null;
try {
    fetcher = new WebPageFetcher("http://google.com");
}

answered Feb 09 '11 at 23:42

Hovercraft Full Of Eels

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3

If you do that, you definitely need to add an if statement to check if `fetcher` is null outside of the try-catch. The alternative is to move the return statement within the try block and do some action if an exception is raised (such as rethrow the exception, return null, etc) – Mark Peters Feb 09 '11 at 23:46
Yes. Thanks for the improvement! – Hovercraft Full Of Eels Feb 09 '11 at 23:48

OscarRyz · Answer 2 · 2011-02-10T00:11:51.953

1

On the return the variable fetcher is out of scope.

Try:

public String getHtml(HttpServletRequest request) {
    try {
         WebPageFetcher fetcher = new WebPageFetcher("http://google.com");
         // return within scope
         return "<div id=\"header\">" + fetcher.getPageContent() + "</div>";
    } catch (Exception e) {
        log.error("WebPageFetcher failed ...");
    }
     return /*something that make sense*/ "<html>500</html>";
}

edited Feb 10 '11 at 00:11

answered Feb 09 '11 at 23:43

OscarRyz

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Again, if you're admitting that an exception could happen, then this is an NPE waiting to happen... – Mark Peters Feb 09 '11 at 23:50
Yeap, I pretty much only worried about the scope, but the return should go in the try/catch... editing... – OscarRyz Feb 10 '11 at 00:10

score 1 · Answer 3 · answered Feb 09 '11 at 23:43

1

The lifetime of the variable fetcher is only within the most enclosing scope, i.e. the most nested pair of brace ({ }) surrounding it. Therefore, it no longer exists by the time you get to the return statement where you're trying to use it.

answered Feb 09 '11 at 23:43

Oliver Charlesworth

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Cannot find symbol error

3 Answers3

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