FileUtil.java

package jpcsp.util;

import java.io.*;
import java.net.URL;

public class FileUtil {
    static public String getExtension(File file) {
        String base = file.getName();
        int index = base.lastIndexOf('.');
        if (index < 0) {
        	return "";
        }
        return base.substring(index + 1).toLowerCase();
    }

    static public void copyStream(InputStream is, OutputStream os) throws IOException {
        byte[] temp = new byte[0x10000];
        while (true) {
            int count = is.read(temp);
            if (count < 0) break;
            os.write(temp, 0, count);
        }
    }

    static public byte[] readInputStream(InputStream is) throws IOException {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        copyStream(is, os);
        return os.toByteArray();
    }

    static public byte[] readURL(URL url) throws IOException {
        try (InputStream inputStream = url.openStream()) {
            return readInputStream(inputStream);
        }
    }

    static public String getURLBaseName(URL url) {
        if (url == null) return null;
        String path = url.getPath();
        int i = path.lastIndexOf('/');
        if (i < 0) {
        	return path;
        }
        return path.substring(i + 1);
    }

    static public void writeBytes(File file, byte[] data) throws FileNotFoundException {
        try (FileOutputStream os = new FileOutputStream(file)) {
            os.write(data);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void readAll(InputStream is, byte[] buffer, int offset, int len) throws IOException {
        int aoffset = offset;
        int remaining = len;
        while (remaining > 0) {
            int read = is.read(buffer, aoffset, remaining);
            if (read > 0) {
                remaining -= read;
                aoffset += read;
            }
        }
    }

    public static File findFolderNameInAncestors(File base, String name) {
        File current = base;
        while (current != null) {
            File file = new File(current, name);
            if (file.exists()) return file.getAbsoluteFile();
            current = current.getParentFile();
        }
        return null;
    }
}