How to output formatted html in java

Question

I'm reading an html file like this:

try {
    BufferedReader bufferReader = new BufferedReader(new FileReader(path));
    String content;
    while((content = bufferReader.readLine()) != null) {
        result += content;
    }
    bufferReader.close();

} catch (Exception e) {
    return e.getMessage();
}

And I want to display it in a GWT textArea, in which i give it to as a String. But the string loses indentations and comes out as a one-liner text. Is there a way to display it properly formatted (with indentations) ?

Answer 1

Well, assuming your textArea understands HTML (I don't know GWT specifically), why don't you prefix it with <pre> then append </pre>?

You'll may still have to escape all the HTML special characters such as & to & and < to <.

Answer 2

That's probably because readLine() chops off the end-of-line character(s). Add them yourself again for each line.

Besides that, use a StringBuilder instead of using += to a String in a loop:

try {
    BufferedReader bufferReader = new BufferedReader(new FileReader(path));
    StringBuilder sb = new StringBuilder();
    String content;
    while ((content = bufferReader.readLine()) != null) {
        sb.append(content);
        sb.append('\n');   // Add line separator
    }
    bufferReader.close();
} catch (Exception e) {
    return e.getMessage();
}

String result = sb.toString();

Answer 3

If your HTML happens to be XHTML, then one thing you can try is to put it into an XML parser such as jdom or dom4j, which usually has some "pretty-print" option.

Answer 4

It might be more efficient to use a FileReader instead--there's no reason why you have to read the text line-by-line. Like Jesper suggested, using a StringBuilder to build your String is more efficient. Also, with FileReader, you don't have to manually append any newlines:

StringBuilder sb = new StringBuilder();
FileReader in = null;
try {
    in = new FileReader(path);
    int read;
    char buf[] = new char[4096];
    while ((read = in.read(buf)) != -1) {
        sb.append(buf, 0, read);
    }
} catch (Exception e) {
    return e.getMessage();
} finally {
    in.close();
}

String result = sb.toString();