我被要求使用霍夫曼代码压缩输入文件并将其写入输出文件.我已经完成了霍夫曼树的结构并生成了霍夫曼代码.但是我不知道如何将这些代码写入文件,以使文件的大小小于原始文件的大小.

现在,我有了以字符串表示形式的代码(例如,“ c”的霍夫曼代码为“ 0100”).有人请帮我把那些写进
 文件.

解决方法:

这是将位流(霍夫曼编码的输出)写入文件的可能实现.

class BitOutputStream {

    private OutputStream out;
    private boolean[] buffer = new boolean[8];
    private int count = 0;

    public BitOutputStream(OutputStream out) {
        this.out = out;
    }

    public void write(boolean x) throws IOException {
        this.count++;
        this.buffer[8-this.count] = x;
        if (this.count == 8){
            int num = 0;
            for (int index = 0; index < 8; index++){
                num = 2*num + (this.buffer[index] ? 1 : 0);
            }

            this.out.write(num - 128);

            this.count = 0;
        }
    }

    public void close() throws IOException {
        int num = 0;
        for (int index = 0; index < 8; index++){
            num = 2*num + (this.buffer[index] ? 1 : 0);
        }

        this.out.write(num - 128);

        this.out.close();
    }

}

通过调用write方法,您将能够一点一点地写入文件(OutputStream).

编辑

对于您的特定问题,要保存每个字符的霍夫曼代码,如果您不想使用其他一些精美的类,则可以简单地使用它-

String huffmanCode = "0100"; // lets say its huffman coding output for c

BitSet huffmanCodeBit = new BitSet(huffmanCode.length());

for (int i = 0; i < huffmanCode.length(); i++) {
    if(huffmanCode.charAt(i) == '1')
        huffmanCodeBit.set(i);
}
String path = Resources.getResource("myfile.out").getPath();
ObjectOutputStream outputStream = null;
try {
    outputStream = new ObjectOutputStream(new FileOutputStream(path));
    outputStream.writeObject(huffmanCodeBit);
} catch (IOException e) {
    e.printStackTrace();
}