Java文件复制多种方法_代码007(未授权)

1、InputSt re a m与OutputStre a m

创建两个文件 – 源和目标。然后我们从源创建InputStrea m并使用OutputStrea m将其写入目标文件进行 java 复制文件操作。

private static void copyFileUsingStream(File source, File dest) throws IOException {
    InputStream is = null;
    OutputStream os = null;
    try {
        is = new FileInputStream(source);
        os = new FileOutputStream(dest);
        byte[] buffer = new byte[1024];
        int length;
        while ((length = is.read(buffer)) > 0) {
            os.write(buffer, 0, length);
        }
    } finally {
        is.close();
        os.close();
    }
}

2、Apac he Comm ons IO FileUtils

co pyFile(File srcFile, File destFile)可用于在 java 中复制文件。如果您已经在项目中使用 Apac he Comm ons IO，那么使用它来简化代码是有意义的。它在内部使用 Java NIO FileChann el，因此如果您尚未将其用于其他功能，则可以避免使用此包装器方法。下面是使用 apache commons io进行java 复制文件操作的方法

private static void copyFileUsingApacheCommonsIO(File source, File dest) throws IOException {
    FileUtils.copyFile(source, dest);
}

3、Files类的copy()方法在 java 中复制文件

private static void copyFileUsingJava7Files(File source, File dest) throws IOException {
    Files.copy(source.toPath(), dest.toPath());
}

4、使用BufferedInputStream/BufferedOutputStream高效字节流进行复制文件

private static void bufferedStreamCopyFile(File srcFile, File desFile) throwsIOException {
         //使用缓冲字节流进行文件复制
         BufferedInputStream bis = new BufferedInputStream(newFileInputStream(srcFile));
         BufferedOutputStream bos = new BufferedOutputStream(newFileOutputStream(desFile));
         byte[] b = new byte[1024];
         Integer len = 0;
         //一次读取1024字节的数据
         while((len = bis.read(b)) != -1) {
             bos.write(b, 0, len);
 }
 bis.close();
 bos.close();
}

private static void readerWriterCopyFile(File srcFile, File desFile) throwsIOException  {
         //使用字符流进行文件复制，注意：字符流只能复制只含有汉字的文件
         FileReader fr = newFileReader(srcFile);
         FileWriter fw = newFileWriter(desFile);
         
         Integer by = 0;
         while((by = fr.read()) != -1) {
 fw.write(by);
 }
         
 fr.close();
 fw.close();
     }

private static void bufferedReaderWriterCopyFile(File srcFile, File desFile)  throwsIOException {
         //使用带缓冲区的高效字符流进行文件复制
         BufferedReader br = new BufferedReader(newFileReader(srcFile));
         BufferedWriter bw = new BufferedWriter(newFileWriter(desFile));
         
         char[] c = new char[1024];
         Integer len = 0;
         while((len = br.read(c)) != -1) {
             bw.write(c, 0, len);
 }
         
         //方式二
         /*String s = null;
 while((s = br.readLine()) != null) {
 bw.write(s);
 bw.newLine();
 }*/
         
 br.close();
 bw.close();
     }

private static void bufferedReaderWriterCopyFile(File srcFile, File desFile)  throwsIOException {
         //使用带缓冲区的高效字符流进行文件复制
        BufferedReader br = new BufferedReader(newFileReader(srcFile));
        BufferedWriter bw = new BufferedWriter(newFileWriter(desFile));
        
         char[] c = new char[1024];
         Integer len = 0;
         while((len = br.read(c)) != -1) {
             bw.write(c, 0, len);
 }
         
         //方式二
         /*String s = null;
 while((s = br.readLine()) != null) {
 bw.write(s);
 bw.newLine();
 }*/
         
 br.close();
 bw.close();
}

private static void copyFileUsingFileChannels(File source, File dest) throws IOException {   
    FileChannel inputChannel = null;   
    FileChannel outputChannel = null;   
  try { 
    inputChannel = new FileInputStream(source).getChannel(); 
    outputChannel = new FileOutputStream(dest).getChannel(); 
    outputChannel.transferFrom(inputChannel, 0, inputChannel.size()); 
  } finally { 
    inputChannel.close(); 
    outputChannel.close(); 
  } 
}