FileChooser.java :  » Code-Analyzer » importscrubber » net » sourceforge » importscrubber » Java Open Source

package net.sourceforge.importscrubber;

import java.io.File;
import java.io.IOException;
import java.util.*;

// note: could have used threads rather than the iterator approach used here,
// but that would have bought us nothing in the command line version (we don't WANT
// a thread scrubbing while this finds files, because most disk systems handle
// that kind of load very poorly).  so since our only concern is allowing the GUI
// to update as files are found, this is just as effective -- and simpler.

public class FileChooser implements Iterator
{
    private String _sourceRoot, _classRoot;
    private boolean _recurse;
    // pre-computed for efficiency
    int relStart;

    private LinkedList possibles = new LinkedList();
    private FilePair nextFp;

    public FileChooser(String sourceRoot, String classRoot, boolean recurse) throws IOException
    {
        File file = new File(sourceRoot);
        if (!file.exists())
            throw new IllegalArgumentException(Resources.ERR_DIR_NOT_EXIST);
        _sourceRoot = file.getCanonicalPath();

        file = new File(classRoot);
        if (!file.isDirectory())
            throw new IllegalArgumentException(Resources.ERR_NOT_DIR);
        if (!file.exists())
            throw new IllegalArgumentException(Resources.ERR_DIR_NOT_EXIST);
        _classRoot = file.getCanonicalPath();

        _recurse = recurse;

        relStart = ImportScrubber.getDirectory(_sourceRoot).length();

        possibles.add(_sourceRoot);
    }

    public void remove
        ()
    {
        throw new UnsupportedOperationException();
    }

    public boolean hasNext()
    {
        if (nextFp == null) {
            try {
                nextFp = (FilePair)next();
            } catch (NoSuchElementException e) {}
        }
        return nextFp != null;
    }

    public Object next() throws NoSuchElementException
    {
        if (nextFp != null) {
            FilePair f = nextFp;
            nextFp = null;
            return f;
        }

        FilePair fp = null;
        while (fp == null) {
            fp = nextPossible();
        }
        return fp;
    }

    // returns null if the sourcefile didn't have a matching classfile.
    private FilePair nextPossible() throws NoSuchElementException
    {
        String s = (String)possibles.removeFirst();
        File tmp = new File(s);
        if (tmp.isDirectory()) {
            if (_recurse) {
                String[] entries = tmp.list(new JavaFileFilter());
                for (int i = 0; i < entries.length; i++) {
                    possibles.add(s + ImportScrubber.FILE_SEPARATOR + entries[i]);
                }
            }
            return nextPossible();
        } else {
            return getPair(tmp);
        }
    }

    private FilePair getPair(File source)
    {
        if (!(source.canRead() && source.canWrite())) {
            return null;
        }
        String relativeSourceFilename = source.getParent().substring(relStart);

        String cfilename = source.getName().substring(0, source.getName().length() - 5) + ".class";
        String classfilename = _classRoot + relativeSourceFilename + ImportScrubber.FILE_SEPARATOR + cfilename;
        File classfile = new File(classfilename);
        if(classfile.exists()) {
            return new FilePair(source, classfile);
        }

        return null;
    }
}