java实现文件归档和还原

package util;

public class DataUtil {
 public static byte[] int2bytes(int src) {
 byte[] rt = new byte[4];
 for(int i=0; i<4; ++i) {
 rt[i] = (byte)(src>>(i*8));
 }
 return rt;
 }
 public static int bytes2int(byte[] src) {
 int rt = 0;
 for(int i=0; i<4; ++i) {
 rt |= (src[i]&0xFF)<<(i*8);
 //字节在进行移位运算时，首先会被转换成int类型，
 //此时若字节的符号位为1，它前面就会补全1，比如：
 //0x80在byte类型时是-128，而转换成int，它的值还是
 //-128，即0xffffff80，而我们移位运算想要的是
 //0x00000080，即前面补全0，跟我们拆时一致。为此，
 //我们让它与0xFF相与，从0xffffff80变为0x00000080。
 }
 return rt;
 }
}

package wfb.binSama;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;

import util.DataUtil;

/**
 * @author binSama
 */
public class Archive {
 
 public static void archive(File[] srcs,File tar) {//归档
 try {
 FileOutputStream fos = new FileOutputStream(tar);
 for(int i=0; i<srcs.length; ++i) {
 //获得文件名
 byte[] fileName = srcs[i].getName().getBytes();
 //获得文件名长度
 byte fileNameLen = (byte)fileName.length;
 //获得文件内容
 FileInputStream fis = new FileInputStream(srcs[i]);
 ByteArrayOutputStream baos = new ByteArrayOutputStream();
 int len = -1;
 byte[] buf = new byte[1024];
 while((len = fis.read(buf)) != -1) {
  baos.write(buf, 0, len);
 }
 baos.close();
 fis.close();
 byte[] fileContent = baos.toByteArray();
 //获得文件内容长度
 byte[] fileContentLen = DataUtil.int2bytes(fileContent.length);
 //写入
 fos.write(fileNameLen);
 fos.write(fileName);
 fos.write(fileContentLen);
 fos.write(fileContent);
 }
 fos.close();
 } catch (Exception e) {
 e.printStackTrace();
 }
 }
 
 public static void unArchive(File src) {//解档到当前文件夹
 try {
 FileInputStream fis = new FileInputStream(src);
 int fileNameLen = -1;
 while((fileNameLen = fis.read()) != -1){
 byte[] byteFileName = new byte[fileNameLen];
 fis.read(byteFileName);
 String fileName = src.getParent() +"\\"+ new String(byteFileName);
 FileOutputStream fos = new FileOutputStream(fileName);
 byte[] byteFileContentLen = new byte[4];
 fis.read(byteFileContentLen);
 int fileContentLen = DataUtil.bytes2int(byteFileContentLen);
 int divisorFileContentLen = fileContentLen / 1024;
 int remainderFileContentLen = fileContentLen % 1024;
 ByteArrayOutputStream baos = new ByteArrayOutputStream();
 byte[] divisorBuf = new byte[1024];
 for(int i=0; i<divisorFileContentLen; ++i) {
  fis.read(divisorBuf);
  baos.write(divisorBuf);
 }
 byte[] remainderBuf = new byte[remainderFileContentLen];
 fis.read(remainderBuf);
 baos.write(remainderBuf);
 baos.close();
 byte[] fileContent = baos.toByteArray();
 fos.write(fileContent);
 }
 fis.close();
 } catch (Exception e) {
 e.printStackTrace();
 }
 }
}

package wfb.binSama;

import java.io.File;

public class Test {
 @org.junit.Test
 public void test() {
 File[] files = new File[3];
 files[0] = new File("E:\\waster\\Archiver1\\1.txt");
 files[1] = new File("E:\\waster\\Archiver1\\2.png");
 files[2] = new File("E:\\waster\\Archiver1\\3.txt");
 File bsm = new File("E:\\waster\\Archiver2\\archive.bsm");
 Archive.archive(files, bsm);
 Archive.unArchive(bsm);
 }
 
}