java.io.File#compareTo ( )源码实例Demo

private static Collection<File> sortFiles(Collection<File> files) {

        final class FileComparator implements Comparator<File> {
            public int compare(File f1, File f2) {
                return f1.compareTo(f2);
            }
        }

        if (files.isEmpty()) {
            return Collections.<File>emptyList();
        }
        if (files.size() == 1) {
            return Collections.singletonList(files.iterator().next());
        }

        SortedSet<File> sortedFiles = new TreeSet<File>(new FileComparator());
        sortedFiles.addAll(files);
        return sortedFiles;
    }
 

/** {inheritDoc} */
public int compare(File f1, File f2) {
    // Need to make sure we read the child namespace before the base
    // namespace.  To do that, we sort the list in reverse order based
    // on the length of the file name.  If two filenames have the same
    // length, then we need to do a lexigraphical comparison to make
    // sure that the filenames themselves are different.

    int lenDif = f2.getAbsolutePath().length() - f1.getAbsolutePath().length();

    if (lenDif != 0) {
        return lenDif;
    }
    return f2.compareTo(f1);
}
 

/** {inheritDoc} */
public int compare(File f1, File f2) {
        // Need to make sure we read the child namespace before the base
        // namespace.  To do that, we sort the list in reverse order based
        // on the length of the file name.  If two filenames have the same
        // length, then we need to do a lexigraphical comparison to make
        // sure that the filenames themselves are different.

        int lenDif = f2.getAbsolutePath().length() - f1.getAbsolutePath().length();

        if (lenDif != 0) {
            return lenDif;
        }
        return f2.compareTo(f1);
    }
 

public boolean navigateBack() {

        File parent = mFileNavigator.getmCurrentNode().getParentFile();
        if(parent==null || parent.compareTo(mFileNavigator.getmCurrentNode())==0 || Constants.externalStorageRoot==null || Constants.externalStorageRoot.compareTo(mFileNavigator.getmCurrentNode())==0 || Constants.internalStorageRoot.compareTo(mFileNavigator.getmCurrentNode())==0)
            return false;
        mFileNavigator.setmCurrentNode(parent);
        triggerFileChanged();
        return true;
    }
 

/**
 * Verify whether the actual directory location of block file has the
 * expected directory path computed using its block ID.
 */
private void verifyFileLocation(File actualBlockDir,
    File bpFinalizedDir, long blockId) {
  File blockDir = DatanodeUtil.idToBlockDir(bpFinalizedDir, blockId);
  if (actualBlockDir.compareTo(blockDir) != 0) {
    LOG.warn("Block: " + blockId
        + " has to be upgraded to block ID-based layout");
  }
}
 

/**
 * Verify whether the actual directory location of block file has the
 * expected directory path computed using its block ID.
 */
private void verifyFileLocation(File actualBlockDir,
    File bpFinalizedDir, long blockId) {
  File blockDir = DatanodeUtil.idToBlockDir(bpFinalizedDir, blockId);
  if (actualBlockDir.compareTo(blockDir) != 0) {
    LOG.warn("Block: " + blockId
        + " has to be upgraded to block ID-based layout");
  }
}
 

public int compare(File left, File right)
{
	if (left.isDirectory())
	{
		if (right.isDirectory())
		{
			return left.compareTo(right);
		}

		return -1;
	}

	return right.isDirectory() ? 1 : left.compareTo(right);
}
 

/**
 * Limit list of possible file to import.
 *
 * @param toFilter set of files to  import
 * @param fileName optional file name
 * @return the filtered file array
 */
private static File[] filterFiles(final File[] toFilter, final String fileName) {
    if (fileName != null && toFilter != null) {
        final File fileAsFilter = new File(fileName);
        for (File file : toFilter) {
            if (file.compareTo(fileAsFilter) == 0) {
                return new File[]{fileAsFilter};
            }
        }
        return new File[0];
    }
    return toFilter;
}
 

@Override
public int compare(File lhs, File rhs) {
    if (lhs.lastModified() == rhs.lastModified()) {
        return lhs.compareTo(rhs);
    } else if (lhs.lastModified() < rhs.lastModified()) {
        return 1;
    } else {
        return -1;
    }
}
 

/** {inheritDoc} */
public int compare(File f1, File f2) {
    // Need to make sure we read the child namespace before the base
    // namespace.  To do that, we sort the list in reverse order based
    // on the length of the file name.  If two filenames have the same
    // length, then we need to do a lexigraphical comparison to make
    // sure that the filenames themselves are different.

    int lenDif = f2.getAbsolutePath().length() - f1.getAbsolutePath().length();

    if (lenDif != 0) {
        return lenDif;
    }
    return f2.compareTo(f1);
}
 

/** {inheritDoc} */
public int compare(File f1, File f2) {
        // Need to make sure we read the child namespace before the base
        // namespace.  To do that, we sort the list in reverse order based
        // on the length of the file name.  If two filenames have the same
        // length, then we need to do a lexigraphical comparison to make
        // sure that the filenames themselves are different.

        int lenDif = f2.getAbsolutePath().length() - f1.getAbsolutePath().length();

        if (lenDif != 0) {
            return lenDif;
        }
        return f2.compareTo(f1);
    }
 

public int compare(File o1, File o2) {
	if (o1.isDirectory() && !o2.isDirectory()) {
		return -1;
	} else if (!o1.isDirectory() && o2.isDirectory()) {
		return 1;
	} else {
		return o1.compareTo(o2);
	}
}
 

/**
 * Add a file to the history and/or switch to the history for the file.
 * 
 * @param newPath Path to add/switch to.
 * @return True if the active data set has changed. False if no change (path
 *         was already in the selected history).
 */
public Pair<Boolean, DirNode> addPath(File file) {
    int depthDelta = file.getPath().split(File.separator).length - mFileDepth;
    if (depthDelta == 1) {
        for (int i = 0; i < mChildren.size(); i++) {
            if (file.compareTo(mChildren.get(i).mFile) == 0) {
                if (i == 0) {
                    // Already in the currently selected history and we
                    // don't need to changes the data set.
                    return new Pair<Boolean, DirNode>(DATA_SET_UNCHANGED, mChildren.get(i));
                }

                DirNode selected = mChildren.remove(i);
                addChild(selected);
                selected.addOrUpdateFragments();
                return new Pair<Boolean, DirNode>(DATA_SET_CHANGED, selected);
            }
        }
        DirNode newChild = new DirNode(this, file, mPagerAdapter, mFragmentManager);
        addChild(newChild);
        newChild.addOrUpdateFragments();
        return new Pair<Boolean, DirNode>(DATA_SET_CHANGED, newChild);
    } else if (depthDelta > 1) {
        // Assume that only the active history will have paths added so
        // pass on down to the zeroth child.
        return mChildren.get(0).addPath(file);
    } else if (TextUtils.equals(mFile.getPath(), file.getPath())) {
        return new Pair<Boolean, DirNode>(DATA_SET_UNCHANGED, this);
    } else if (mParent == null) {
        throw new RuntimeException("Illegal attempt to add " + file.getPath()
                + " to parent node where no parent exists.");
    } else {
        return mParent.addPath(file);
    }
}
 

public int compare(File left, File right)
{
	return left.compareTo(right);
}
 

private boolean isBaseDirectory(File directory) {
    return directory.compareTo(baseDirectory) == 0;
}
 

/**
 * Compare the two files using the {@link File#compareTo(File)} method.
 * 
 * @param file1 The first file to compare
 * @param file2 The second file to compare
 * @return the result of calling file1's
 * {@link File#compareTo(File)} with file2 as the parameter.
 */
public int compare(File file1, File file2) {
    return file1.compareTo(file2);
}
 

/**
 * Compare the two files using the {@link File#compareTo(File)} method.
 * 
 * @param file1 The first file to compare
 * @param file2 The second file to compare
 * @return the result of calling file1's
 * {@link File#compareTo(File)} with file2 as the parameter.
 */
public int compare(final File file1, final File file2) {
    return file1.compareTo(file2);
}
 

@Override
public int compare(final File o1, final File o2) {

    return o2.compareTo(o1);

}