java - 我有一个 ArrayList 在目录中存储几个 pdf 文件位置。如何将pdf的内容读取为字节数组并对其进行压缩

Question

ArrayList 是这样的 - [ Desktop/folder/abc.pdf, Desktop/folder/xyz.pdf ]

我正在做这样的事情

public byte[] compressByteArray(byte[] bytes){

        ByteArrayOutputStream baos = null;
        Deflater dfl = new Deflater();
        dfl.setLevel(Deflater.BEST_COMPRESSION);
        dfl.setInput(bytes);
        dfl.finish();
        baos = new ByteArrayOutputStream();
        byte[] tmp = new byte[4*1024];
        try{
            while(!dfl.finished()){
                int size = dfl.deflate(tmp);
                baos.write(tmp, 0, size);
            }
        } catch (Exception ex){

        } finally {
            try{
                if(baos != null) baos.close();
            } catch(Exception ex){}
        }

        return baos.toByteArray();
    }