哈夫曼算法实现文件夹的压缩与解压

package HRJ; import java.io.*; import java.util.ArrayList; import java.util.ArrayList; public class Handle { static void Compress(String fileName){ File file = new File(fileName); ArrayList<String> fileArrayList = new ArrayList<>(); fileArrayList = Assistance.getAllFilePaths(file,fileArrayList); String target = Assistance.gettargetname(fileName); File tf = new File(target); //如果是文件夹 if(file.isDirectory()) { try { tf.createNewFile(); } catch (IOException e) { e.printStackTrace(); return; } try { ArrayList<Unit> biao = new ArrayList<>(); ArrayList<HCode> code; Assistance.readFileByBytes(fileName, biao);//读取所有文件获得字符哈夫曼编码表 ArrayList<Unit> bb = new ArrayList<>(); for(int i = 0;i<biao.size();i++){ Unit help = new Unit(biao.get(i).content, biao.get(i).quantity); bb.add(help); } if(biao.size()==0) code = null; else { Haffmantree tree = new Haffmantree(bb); Code c = new Code(tree); code = c.tabel; } File targetfile; FileOutputStream fos = new FileOutputStream(target); BufferedOutputStream bos = new BufferedOutputStream(fos); if(biao.size()==0) //为了之后读取的时候区别到底是0还是256溢出成了0 bos.write(0); else bos.write(1); bos.write(biao.size()); int i; String binary = ""; int By; //写入字符频率表 for(i = 0;i<biao.size();i++){ int ch = biao.get(i).content; bos.write((byte)ch); binary = Integer.toBinaryString(biao.get(i).quantity); bos.write(binary.length()); while (binary.length()>8){ By = ((binary.charAt(0) - 48) * 128 + (binary.charAt(1) - 48) * 64 + (binary.charAt(2) - 48) * 32 + (binary.charAt(3) - 48) * 16 + (binary.charAt(4) - 48) * 8 + (binary.charAt(5) - 48) * 4 + (binary.charAt(6) - 48) * 2 + (binary.charAt(7) - 48)); bos.write((byte)By); binary = binary.substring(8); } int two = 1; By = 0; for(int zero = binary.length();zero>0;zero--) { By=By+(binary.charAt(zero-1)-48)*two; two*=2; } bos.write((byte)By); } int filenamelength; for(String f:fileArrayList){ //写入文件夹 if((targetfile = new File(f)).isDirectory()){ filenamelength = targetfile.getAbsolutePath().length(); bos.write(filenamelength); for(int g = 0; g<filenamelength;g++){ bos.write(targetfile.getAbsolutePath().charAt(g)); } } //写入文件 else { filenamelength = targetfile.getAbsolutePath().length(); bos.write(filenamelength); for(int g = 0; g<filenamelength;g++){ bos.write(targetfile.getAbsolutePath().charAt(g)); } Long filelength = targetfile.length(); String b = ""; b = Long.toBinaryString(filelength); bos.write(b.length());//文件长度二进制码的长度 FileInputStream fis = new FileInputStream(f); BufferedInputStream bis = new BufferedInputStream(fis); if(filelength==0L){//文件长度为零 bos.write(0); } byte[] B = new byte[1024000000]; int bytelength, temp; while ((bytelength = bis.read(B))!=-1) { for (i = 0; i < bytelength; i++) { temp = 0|(B[i]&0x000000ff); b+=code.get(temp).code; while (b.length()>8) { By = (((b.charAt(0) - 48) << 7) + ((b.charAt(1) - 48) << 6) + ((b.charAt(2) - 48) << 5) + ((b.charAt(3) - 48) << 4) + ((b.charAt(4) - 48) << 3) + ((b.charAt(5) - 48) << 2) + ((b.charAt(6) - 48) << 1) + (b.charAt(7) - 48)); bos.write((byte) By);//第一个By为文件长度 b = b.substring(8); } } } while (b.length()%8!=0){ b+="0";//补零 } By = (((b.charAt(0) - 48) << 7) + ((b.charAt(1) - 48) << 6) + ((b.charAt(2) - 48) << 5) + ((b.charAt(3) - 48) << 4) + ((b.charAt(4) - 48) << 3) + ((b.charAt(5) - 48) << 2) + ((b.charAt(6) - 48) << 1) + (b.charAt(7) - 48)); if(targetfile.length()!=0) { bos.write((byte) By); } } } bos.close(); } catch (IOException e){ e.printStackTrace(); return; } } //如果是单个文件 else if(file.isFile()){ ArrayList<Unit> a = new ArrayList<>(); Assistance.readFileByBytes(fileName,a);//读取文件 ArrayList<Unit> biao = new ArrayList<>(); for(int i = 0;i<a.size();i++){ Unit help = new Unit(a.get(i).content, a.get(i).quantity); biao.add(help); } Haffmantree tree = new Haffmantree(a); Code c = new Code(tree); ArrayList<HCode> code = c.tabel; String fn = fileName.substring(fileName.lastIndexOf(".")); String b = new String(); int By = 0; try { tf.createNewFile(); } catch (IOException e){ e.printStackTrace(); } String binary = new String(); InputStream in = null; try { FileOutputStream fos = new FileOutputStream(target); BufferedOutputStream bos = new BufferedOutputStream(fos); in = new FileInputStream(file); for(int g = 0; g<fn.length();g++){ bos.write(fn.charAt(g)); } bos.write(' ');//标志着文件格式结束 int tempbyte=0, i; //写入字符频率表 bos.write(biao.size()); for(i = 0;i<biao.size();i++){ bos.write((int)biao.get(i).content); binary = Integer.toBinaryString(biao.get(i).quantity); bos.write(binary.length()); //字符频率的二进制码的�