Java文件拷貝的幾種實現方案

在jdk1.7之前，java中沒有直接的類提供文件復制功能。下面就文件復制，提出幾種方案。

jdk1.7中的文件復制

在jdk1.7版本中可以直接使用Files.copy(File srcFile, File destFile)方法即可。

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

使用FileInputStream復制

/**
 *
 * @Title: copyFileUsingStream
 * @Description: 使用Stream拷貝文件
 * @param: @param source
 * @param: @param dest
 * @param: @throws IOException
 * @return: void
 * @throws
 */
public 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();
    }
}

使用FileChannel實現復制

/**
 * @throws IOException
 *
 * @Title: copyFileUsingChannel
 * @Description: 使用Channel拷貝文件
 * @param: @param source
 * @param: @param dest
 * @return: void
 * @throws
 */
public static void copyFileUsingChannel(File source, File dest) throws IOException {
    FileChannel sourceChannel = null;
    FileChannel destChannel = null;
    try {
        sourceChannel = new FileInputStream(source).getChannel();
        destChannel = new FileOutputStream(dest).getChannel();
        destChannel.transferFrom(sourceChannel, 0, sourceChannel.size());
    } finally {
        sourceChannel.close();
        destChannel.close();
    }
}

使用Apache Commons IO包中的FileUtils.copyFile復制

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

使用IO重定向實現復制

/**
 *
 * @Title: copyFileUsingRedirection
 * @Description: 使用Redirection拷貝文件
 * @param: @param source
 * @param: @param dest
 * @param: @throws IOException
 * @return: void
 * @throws
 */
public static void copyFileUsingRedirection(File source, File dest) throws IOException {
    FileInputStream in = null;
    PrintStream out = null;
    try {
        in = new FileInputStream(source);
        out = new PrintStream(dest);
        System.setIn(in);
        System.setOut(out);
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()) {
            System.out.println(sc.nextLine());
        }
    } finally{
        in.close();
        out.close();
    }
}

來自：http://www.jianshu.com/p/56843fdc2986