Java文件复制多种方法

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 class="lazy" data-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 class="lazy" data-srcFile, File desFile) throwsIOException {         //使用缓冲字节流进行文件复制         BufferedInputStream bis = new BufferedInputStream(newFileInputStream(class="lazy" data-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 class="lazy" data-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(class="lazy" data-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 class="lazy" data-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(class="lazy" data-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 class="lazy" data-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(class="lazy" data-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