如何以编程方式将文件复制到另一个目录? [英] How to copy a file to another directory programmatically?

问题描述

在目录中有一个 image文件.如何将这个图像文件复制到另一个刚刚创建的目录中?这两个目录位于设备的同一内部存储中:)

There is an image file inside a directory. How to copy this image file into another directory that was just created ? The two directories are on the same internal storage of the device :)

推荐答案

您可以使用这些功能.第一个将复制带有所有子项的整个目录，或者如果您传入文件，则复制一个文件.第二个仅对文件有用，第一个中的每个文件都被调用.

You can use these functions. The first one will copy whole directory with all children or a single file if you pass in a file. The second one is only usefull for files and is called for each file in the first one.

还请注意，您需要具有执行此操作的权限

Also note you need to have permissions to do that

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />  

功能:

 public static void copyFileOrDirectory(String srcDir, String dstDir) {

        try {
            File src = new File(srcDir);
            File dst = new File(dstDir, src.getName());

            if (src.isDirectory()) {

                String files[] = src.list();
                int filesLength = files.length;
                for (int i = 0; i < filesLength; i++) {
                    String src1 = (new File(src, files[i]).getPath());
                    String dst1 = dst.getPath();
                    copyFileOrDirectory(src1, dst1);

                }
            } else {
                copyFile(src, dst);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void copyFile(File sourceFile, File destFile) throws IOException {
        if (!destFile.getParentFile().exists())
            destFile.getParentFile().mkdirs();

        if (!destFile.exists()) {
            destFile.createNewFile();
        }

        FileChannel source = null;
        FileChannel destination = null;

        try {
            source = new FileInputStream(sourceFile).getChannel();
            destination = new FileOutputStream(destFile).getChannel();
            destination.transferFrom(source, 0, source.size());
        } finally {
            if (source != null) {
                source.close();
            }
            if (destination != null) {
                destination.close();
            }
        }
    }

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