java使用nio2拷贝文件的示例

import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.FileVisitor;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import java.nio.file.attribute.BasicFileAttributes;
import java.nio.file.attribute.FileTime;
import java.util.Stack;

import org.apache.log4j.Logger;

import com.xyq.myfile.cope.entity.PathType;
import com.xyq.util.MD5Util;

/***
* 基于jdk7的拷贝算法
*
* @author xyq
*
*/
public class MyFiles2 {

private String src;
private String tar;
private Path srcPath;
private Path tarPath;
private int reCount = 3;
private boolean isCover = false;
private boolean useMd5 = false;
private int subNameNum = 0;
// log4j对象
private Logger logger;
// 在文件夹-->文件夹模式中，是否拷贝全路径,默认不拷贝
private boolean isCopeAllPath = false;

public MyFiles2(String src, String tar) {

  this.src = src;
  this.tar = tar;
  this.srcPath = Paths.get(src);
  this.tarPath = Paths.get(tar);
}

public MyFiles2() {
}

public String getSrc() {
return src;
}

public void setSrc(String src) {
this.src = src;
this.srcPath = Paths.get(src);
}

public String getTar() {
return tar;
}

public void setTar(String tar) {
this.tar = tar;
this.tarPath = Paths.get(tar);
}

public int getReCount() {
return reCount;
}

public void setReCount(int reCount) {
this.reCount = reCount;
}

public boolean isCover() {
return isCover;
}

public void setCover(boolean isCover) {
this.isCover = isCover;
}

public Logger getLogger() {
return logger;
}

public void setLogger(Logger logger) {
this.logger = logger;
}

public boolean isUseMd5() {
return useMd5;
}

public void setUseMd5(boolean useMd5) {
this.useMd5 = useMd5;
}

public boolean isCopeAllPath() {
return isCopeAllPath;
}

public void setCopeAllPath(boolean isCopeAllPath) {
this.isCopeAllPath = isCopeAllPath;
}

public boolean copeFileCore(PathType... types) {

  if (initCheck() && initCheck2s(this.srcPath, false))
   return copeFileCore(this.srcPath, this.tarPath, reCount, isCover,
     types);
  return false;
}

private boolean initCheck() {

  if (this.srcPath == null) {
   logInfo("原始路径未设置,程序无法启动~~");
   return false;
  } else if (this.tarPath == null) {
   logInfo("目标路径未设置,程序无法启动~~");
   return false;
  } else if (!Files.exists(srcPath)) {
   logInfo("原始路径不存在,程序无法启动~~");
   return false;
  } else if (!Files.exists(tarPath.getRoot())) {
   logInfo("目标路径的根盘符不存在,程序无法启动~~");
   return false;
  }
  return true;
}

private boolean initCheck2s(Path path, boolean dOrF) {

  if (!Files.isDirectory(path)) {
   if (dOrF) {
    logInfo(path + "不是一个有效的文件夹");
    return false;
   }
  } else if (!dOrF) {
   logInfo(path + "不是一个有效的文件");
   return false;
  }
  return true;
}

/****
* 拷贝文件算法
*
* @param path1
*            原始路径
* @param path2
*            目标路径
* @param reCount
*            重复次数
* @param isCover
*            是否覆盖拷贝
* @param types
*            你所写的目标路径是文件还是文件夹，可以不写，默认是文件
* @return
*/
public boolean copeFileCore(Path path1, Path path2, int reCount,
   boolean isCover, PathType... types) {

  // 如果原始文件不存在，就直接异常
  if (!initCheck() || !initCheck2s(path1, false))
   return false;
  PathType type = PathType.FILES;
  if (types != null && types.length > 0) {
   type = types[0];
   // 如果目标是一个文件夹,并且指定是往一个文件夹拷贝的时候
   if (type.equals(PathType.DIRS)) {
    path2 = Paths.get(path2.toString(), path1.getFileName()
      .toString());
   }
  }
  // 如果目标文件已经存在，就判断是否相同，相同就不用拷贝了
  if (Files.exists(path2)) {
   if (Files.isDirectory(path2) && PathType.FILES.equals(type)) {
    logInfo(path2 + "已经存在,它是一个文件夹而不是文件");
    return false;
   }
   if (isSameFile(path1, path2, useMd5))
    return true;
  }
  // 当目标文件不存在的时候
  else {
   Path parPath = path2.getParent();
   // 如果目标文件的父类文件夹不存在,就尝试创建
   if (!Files.exists(parPath))
    for (int i = 1; i < reCount; i++) {
     try {
      Files.createDirectories(parPath);
      break;
     } catch (Exception e) {
      if (i == reCount) {
       logInfo(e);
       return false;
      }
     }
    }
  }

  for (int i = 1; i <= reCount; i++) {
   try {
    if (isCover)
     Files.copy(path1, path2,
       StandardCopyOption.REPLACE_EXISTING,
       StandardCopyOption.COPY_ATTRIBUTES);
    else
     Files.copy(path1, path2, StandardCopyOption.COPY_ATTRIBUTES);
    // 同步最后修改时间
    synLastFileTime(path1, path2);
    break;
   } catch (IOException e) {
    // 如果在指定时间内都无法完成拷贝，那么就果断记录到异常信息中
    if (i == reCount) {
     logInfo(e);
     return false;
    }
   }
  }
  return true;

}

public void copeDir() {

  if (!initCheck() || !initCheck2s(srcPath, true))
   return;
  copeDir(this.srcPath.toString(), this.tarPath.toString());
}

/***
* 拷贝文件夹保护层
*
* @param path1
* @param path2
*/
public void copeDir(String path1, final String path2) {

  if (!initCheck() || !initCheck2s(srcPath, true))
   return;
  Path p1 = Paths.get(path1);
  final Path tarPath = Paths.get(path2);
  if (!isCopeAllPath)
   subNameNum = srcPath.getNameCount() - 1;
  try {
   Files.walkFileTree(p1, new FileVisitor<Path>() {

Path p2 = null;
Stack<Path> dirStack = new Stack<Path>();

    @Override
    public FileVisitResult preVisitDirectory(Path dir,
      BasicFileAttributes attrs) throws IOException {

     // 当使用不拷贝全路径时，作为本文件夹的名字节点的记录位置
     // if (!copeAllPath)
     /****
      * 如果是相同的文件夹，那么就跳过无需拷贝.
      */
     if (isSamePath(dir, tarPath)) {
      System.out.println("是相同的，跳过!!!!!!!!!!!!!!!!!");
      return FileVisitResult.SKIP_SUBTREE;
     }
     p2 = replacePath(dir, path2, subNameNum);
     if (dir.toFile().length() == 0 && !Files.exists(p2))
      Files.createDirectories(p2);
     dirStack.push(p2);
     return FileVisitResult.CONTINUE;

}

    @Override
    public FileVisitResult visitFile(Path file,
      BasicFileAttributes attrs) throws IOException {

     Path toFilePath = Paths.get(dirStack.peek().toString(),
       file.getFileName().toString());
     copeFileCore(file, toFilePath, 3, true);
     return FileVisitResult.CONTINUE;

}

    @Override
    public FileVisitResult visitFileFailed(Path file,
      IOException exc) throws IOException {

return FileVisitResult.CONTINUE;
}

    @Override
    public FileVisitResult postVisitDirectory(Path dir,
      IOException exc) throws IOException {
     if (!dirStack.isEmpty())
      dirStack.pop();
     return FileVisitResult.CONTINUE;
    }

   });
  } catch (IOException e) {
   logInfo(e);
  }
}

/***
* 替换Path
*
* @param path1
* @param path2
* @return
*/
private Path replacePath(Path path1, String path2, int nameCountNum) {

  if (path1.getNameCount() == 0 && path1.equals(path1.getRoot()))
   return Paths.get(path2);
  return Paths.get(path2,
    path1.subpath(nameCountNum, path1.getNameCount()).toString());
}

/***
* 要么是地址完全相同，要么就是原始文件的父类与目标相同，因为程序支持拷贝到父类
*
* @param path1
* @param path2
* @return
*/
private boolean isSamePath(Path path1, Path path2) {

  if (path1.equals(path2))
   return true;
  return false;
}

/***
* 同步文件的修改时间
*
* @param path1
* @param path2
* @return
*/
public boolean synLastFileTime(Path path1, Path path2) {

  FileTime srcPathTime;
  try {
   srcPathTime = Files.getLastModifiedTime(path1);
   Files.setLastModifiedTime(path2, srcPathTime);
   return srcPathTime.equals(Files.getLastModifiedTime(path2));
  } catch (IOException e) {
   logInfo(e);
   return false;
  }
}

/***
* 判断两个文件是否相同
*
* @param path1
* @param path2
* @return
*/
public boolean isSameFile(Path path1, Path path2, boolean useMd5) {

  try {
   // 只要两个文件长度不一致，就绝对不是一个文件
   if (Files.size(path1) != Files.size(path2))
    return false;
   // 如果是最后的修改时间不一样，就直接使用MD5验证
   else if (!Files.getLastModifiedTime(path1).equals(
     Files.getLastModifiedTime(path2))
     || useMd5)
    return MD5Util.getFileMD5String(path1.toFile()).equals(
      MD5Util.getFileMD5String(path2.toFile()));
   return true;
  } catch (Exception e) {
   logInfo(e);
   return false;
  }
}

/***
* 针对异常处理的
*/
private void logInfo(Exception e) {

  if (this.logger != null)
   logger.error(e.getMessage());
  else if (e != null)
   System.out.println("异常:" + e.getMessage());
}

private void logInfo(String errorMessage) {

  if (this.logger != null)
   logger.error(errorMessage);
  else
   System.out.println("异常:" + errorMessage);
}

public static void main(String[] args) {

  // new MyFiles2("e:/t/1.txt", "e:/3/33").copeFileCore();
  MyFiles2 my = new MyFiles2("e:/ttt/tt/t/1.txt", "e:/3/33.txt");
  my.copeFileCore(PathType.DIRS);
}
}

public enum PathType {

FILES,DIRS;
}

import java.io.Closeable;

public class CloseIoUtil {

/***
* 关闭IO流
*
* @param cls
*/
public static void closeAll(Closeable... cls) {

  if (cls != null) {
   for (Closeable cl : cls) {
    try {
     if (cl != null)
      cl.close();
    } catch (Exception e) {

    } finally {
     cl = null;
    }
   }
  }
}
}

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Util {

protected static char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6',
   '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
protected static MessageDigest messagedigest = null;
static {
  try {
   messagedigest = MessageDigest.getInstance("MD5");
  } catch (NoSuchAlgorithmException e) {
   e.printStackTrace();
  }
}

public static String getFileMD5String(File file) throws IOException {

  /***
   * MappedByteBuffer是NIO的API，使用这个API会有一个bug，
   * 当使用 FileChannel.map 方法时，MappedByteBuffer 已经在系统内占用了一个句柄，
   * 而使用 FileChannel.close 方法是无法释放这个句柄的，、
   * 且FileChannel有没有提供类似 unmap 的方法，因此会出现无法删除文件的情况。
   */
  // FileInputStream in = new FileInputStream(file);
  // FileChannel ch = in.getChannel();
  // MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY,
  // 0,
  // file.length());

  InputStream fis = null;
  BufferedInputStream bis = null;
        fis = new FileInputStream(file);
        bis = new BufferedInputStream(fis);
        byte[] buffer = new byte[2048];
        int numRead = 0;
        while ((numRead = bis.read(buffer)) > 0) {
            messagedigest.update(buffer, 0, numRead);
        }
        CloseIoUtil.closeAll(bis,fis);
        return bufferToHex(messagedigest.digest());
}

public static String getMD5String(String s) {
return getMD5String(s.getBytes());
}

public static String getMD5String(byte[] bytes) {
messagedigest.update(bytes);
return bufferToHex(messagedigest.digest());
}

private static String bufferToHex(byte bytes[]) {
return bufferToHex(bytes, 0, bytes.length);
}

private static String bufferToHex(byte bytes[], int m, int n) {
  StringBuffer stringbuffer = new StringBuffer(2 * n);
  int k = m + n;
  for (int l = m; l < k; l++) {
   appendHexPair(bytes[l], stringbuffer);
  }
  return stringbuffer.toString();
}

private static void appendHexPair(byte bt, StringBuffer stringbuffer) {
  char c0 = hexDigits[(bt & 0xf0) >> 4];
  char c1 = hexDigits[bt & 0xf];
  stringbuffer.append(c0);
  stringbuffer.append(c1);
}

public static boolean checkPassword(String password, String md5PwdStr) {
String s = getMD5String(password);
return s.equals(md5PwdStr);
}

public static void main(String[] args) throws IOException {

  File big = new File("e:/sss.txt");
  String md5 = getFileMD5String(big);
  //
  // long end = System.currentTimeMillis();
  // System.out.println("md5:" + md5);
  // System.out.println("time:" + ((end - begin) / 1000) + "s");

System.out.println(md5);