java实现文件复制上传操作

利用Java复制文件到处都可以用到，这里总结了一个类供大家参考。里面总共有两个方法：

public static boolean copyFile(String srcFileName, String destFileName,boolean overlay); 
public static boolean copyDirectory(String srcDirName, String destDirName,boolean overlay) ; 

其中：
srcFileName 待复制的文件名
descFileName  目标文件名
overlay  如果目标文件存在，是否覆盖
如果复制成功返回true，否则返回false

代码：

 import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.OutputStream; 
 
import javax.swing.JOptionPane; 
 
 
public class CopyFileUtil { 
 
  private static String MESSAGE = ""; 
 
   
  public static boolean copyFile(String srcFileName, String destFileName, 
      boolean overlay) { 
    File srcFile = new File(srcFileName); 
 
    // 判断源文件是否存在 
    if (!srcFile.exists()) { 
      MESSAGE = "源文件：" + srcFileName + "不存在！"; 
      JOptionPane.showMessageDialog(null, MESSAGE); 
      return false; 
    } else if (!srcFile.isFile()) { 
      MESSAGE = "复制文件失败，源文件：" + srcFileName + "不是一个文件！"; 
      JOptionPane.showMessageDialog(null, MESSAGE); 
      return false; 
    } 
 
    // 判断目标文件是否存在 
    File destFile = new File(destFileName); 
    if (destFile.exists()) { 
      // 如果目标文件存在并允许覆盖 
      if (overlay) { 
 // 删除已经存在的目标文件，无论目标文件是目录还是单个文件 
 new File(destFileName).delete(); 
      } 
    } else { 
      // 如果目标文件所在目录不存在，则创建目录 
      if (!destFile.getParentFile().exists()) { 
 // 目标文件所在目录不存在 
 if (!destFile.getParentFile().mkdirs()) { 
   // 复制文件失败：创建目标文件所在目录失败 
   return false; 
 } 
      } 
    } 
 
    // 复制文件 
    int byteread = 0; // 读取的字节数 
    InputStream in = null; 
    OutputStream out = null; 
 
    try { 
      in = new FileInputStream(srcFile); 
      out = new FileOutputStream(destFile); 
      byte[] buffer = new byte[1024]; 
 
      while ((byteread = in.read(buffer)) != -1) { 
 out.write(buffer, 0, byteread); 
      } 
      return true; 
    } catch (FileNotFoundException e) { 
      return false; 
    } catch (IOException e) { 
      return false; 
    } finally { 
      try { 
 if (out != null) 
   out.close(); 
 if (in != null) 
   in.close(); 
      } catch (IOException e) { 
 e.printStackTrace(); 
      } 
    } 
  } 
 
   
  public static boolean copyDirectory(String srcDirName, String destDirName, 
      boolean overlay) { 
    // 判断源目录是否存在 
    File srcDir = new File(srcDirName); 
    if (!srcDir.exists()) { 
      MESSAGE = "复制目录失败：源目录" + srcDirName + "不存在！"; 
      JOptionPane.showMessageDialog(null, MESSAGE); 
      return false; 
    } else if (!srcDir.isDirectory()) { 
      MESSAGE = "复制目录失败：" + srcDirName + "不是目录！"; 
      JOptionPane.showMessageDialog(null, MESSAGE); 
      return false; 
    } 
 
    // 如果目标目录名不是以文件分隔符结尾，则加上文件分隔符 
    if (!destDirName.endsWith(File.separator)) { 
      destDirName = destDirName + File.separator; 
    } 
    File destDir = new File(destDirName); 
    // 如果目标文件夹存在 
    if (destDir.exists()) { 
      // 如果允许覆盖则删除已存在的目标目录 
      if (overlay) { 
 new File(destDirName).delete(); 
      } else { 
 MESSAGE = "复制目录失败：目的目录" + destDirName + "已存在！"; 
 JOptionPane.showMessageDialog(null, MESSAGE); 
 return false; 
      } 
    } else { 
      // 创建目的目录 
      System.out.println("目的目录不存在，准备创建。。。"); 
      if (!destDir.mkdirs()) { 
 System.out.println("复制目录失败：创建目的目录失败！"); 
 return false; 
      } 
    } 
 
    boolean flag = true; 
    File[] files = srcDir.listFiles(); 
    for (int i = 0; i < files.length; i++) { 
      // 复制文件 
      if (files[i].isFile()) { 
 flag = CopyFileUtil.copyFile(files[i].getAbsolutePath(), 
     destDirName + files[i].getName(), overlay); 
 if (!flag) 
   break; 
      } else if (files[i].isDirectory()) { 
 flag = CopyFileUtil.copyDirectory(files[i].getAbsolutePath(), 
     destDirName + files[i].getName(), overlay); 
 if (!flag) 
   break; 
      } 
    } 
    if (!flag) { 
      MESSAGE = "复制目录" + srcDirName + "至" + destDirName + "失败！"; 
      JOptionPane.showMessageDialog(null, MESSAGE); 
      return false; 
    } else { 
      return true; 
    } 
  } 
 
  public static void main(String[] args) { 
    String srcDirName = "C:/test/test0/test1"; 
    String destDirName = "c:/ttt"; 
    CopyFileUtil.copyDirectory(srcDirName, destDirName, true); 
  } 
} 

不考虑多线程优化，单线程文件复制最快的方法是(文件越大该方法越有优势，一般比常用方法快30+%):

private static void nioTransferCopy(File source, File target) { 
  FileChannel in = null; 
  FileChannel out = null; 
  FileInputStream inStream = null; 
  FileOutputStream outStream = null; 
  try { 
    inStream = new FileInputStream(source); 
    outStream = new FileOutputStream(target); 
    in = inStream.getChannel(); 
    out = outStream.getChannel(); 
    in.transferTo(0, in.size(), out); 
  } catch (IOException e) { 
    e.printStackTrace(); 
  } finally { 
    close(inStream); 
    close(in); 
    close(outStream); 
    close(out); 
  } 
} 

如果需要监测复制进度，可以用第二快的方法(留意buffer的大小，对速度有很大影响):

private static void nioBufferCopy(File source, File target) { 
  FileChannel in = null; 
  FileChannel out = null; 
  FileInputStream inStream = null; 
  FileOutputStream outStream = null; 
  try { 
    inStream = new FileInputStream(source); 
    outStream = new FileOutputStream(target); 
    in = inStream.getChannel(); 
    out = outStream.getChannel(); 
    ByteBuffer buffer = ByteBuffer.allocate(4096); 
    while (in.read(buffer) != -1) { 
      buffer.flip(); 
      out.write(buffer); 
      buffer.clear(); 
    } 
  } catch (IOException e) { 
    e.printStackTrace(); 
  } finally { 
    close(inStream); 
    close(in); 
    close(outStream); 
    close(out); 
  } 
} 

常用的方法1是:

private static void customBufferBufferedStreamCopy(File source, File target) { 
  InputStream fis = null; 
  OutputStream fos = null; 
  try { 
    fis = new BufferedInputStream(new FileInputStream(source)); 
    fos = new BufferedOutputStream(new FileOutputStream(target)); 
    byte[] buf = new byte[4096]; 
    int i; 
    while ((i = fis.read(buf)) != -1) { 
      fos.write(buf, 0, i); 
    } 
  } 
  catch (Exception e) { 
    e.printStackTrace(); 
  } finally { 
    close(fis); 
    close(fos); 
  } 
} 

常用的方法2是:

private static void customBufferStreamCopy(File source, File target) { 
  InputStream fis = null; 
  OutputStream fos = null; 
  try { 
    fis = new FileInputStream(source); 
    fos = new FileOutputStream(target); 
    byte[] buf = new byte[4096]; 
    int i; 
    while ((i = fis.read(buf)) != -1) { 
      fos.write(buf, 0, i); 
    } 
  } 
  catch (Exception e) { 
    e.printStackTrace(); 
  } finally { 
    close(fis); 
    close(fos); 
  } 
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。