import java.io.*;

/** Utility methods for common stream operations. */
public class StreamUtils {

    /** Copy all bytes from in to out using an 8 KB buffer. */
    public static void copy(InputStream in, OutputStream out) throws IOException {
        byte[] buf = new byte[8192];
        int n;
        while ((n = in.read(buf)) != -1) out.write(buf, 0, n);
    }

    /** Read a text file into a String. Always specify encoding. */
    public static String readText(File file, String encoding) throws IOException {
        StringBuilder sb = new StringBuilder();
        BufferedReader reader = new BufferedReader(
            new InputStreamReader(new FileInputStream(file), encoding));
        try {
            String line;
            while ((line = reader.readLine()) != null) sb.append(line).append('\n');
        } finally {
            reader.close();
        }
        return sb.toString();
    }

    /** Write text to a file, creating or appending as requested. */
    public static void writeText(File file, String text, String encoding, boolean append)
            throws IOException {
        PrintWriter w = new PrintWriter(new BufferedWriter(
            new OutputStreamWriter(new FileOutputStream(file, append), encoding)));
        try { w.print(text); } finally { w.close(); }
    }

    /** Serialise an object to a file. */
    public static void serialise(Object obj, File file) throws IOException {
        ObjectOutputStream oos = new ObjectOutputStream(
            new BufferedOutputStream(new FileOutputStream(file)));
        try { oos.writeObject(obj); } finally { oos.close(); }
    }

    /** Deserialise an object from a file. */
    public static Object deserialise(File file) throws IOException, ClassNotFoundException {
        ObjectInputStream ois = new ObjectInputStream(
            new BufferedInputStream(new FileInputStream(file)));
        try { return ois.readObject(); } finally { ois.close(); }
    }
}