InputStream与OutputStream
创建两个文件 - 源和目标。然后我们从源创建InputStream并使用OutputStream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(); }}
Apache Commons IO FileUtils
copyFile(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 Apache Commons IO,那么使用它来简化代码是有意义的。它在内部使用 Java NIO FileChannel,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);}
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());}
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();}
使用FileReader/FileWriter字符流进行文件复制
注意这种方式只能复制只包含字符的文件,也就意味着你用记事本打开该文件你能够读懂
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(); }
使用BufferedReader/BufferedWriter高效字符流进行文件复制
意这种方式只能复制只包含字符的文件,也就意味着你用记事本打开该文件你能够读懂
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 br.close(); bw.close(); }
使用BufferedReader/BufferedWriter高效字符流进行文件复制
注意这种方式只能复制只包含字符的文件,也就意味着你用记事本打开该文件你能够读懂
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 br.close(); bw.close();}
使用FileChannel复制
Java NIO包括transferFrom方法,根据文档应该比文件流复制的速度更快
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(); } }
来源地址:https://blog.csdn.net/LookingTomorrow/article/details/129786440