Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Apache License 

import java.io.File;

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;
import android.annotation.TargetApi;

import android.os.Build;

import android.support.annotation.NonNull;

import android.util.Log;

public class Main {
    public static Context applicationContext;

    /**
     * Determine if a file is on external sd card. (Kitkat or higher.)
     *
     * @param file The file.
     * @return true if on external sd card.
     */
    @TargetApi(Build.VERSION_CODES.KITKAT)
    public static boolean isOnExtSdCard(@NonNull final File file) {
        return getExtSdCardFolder(file) != null;
    }

    /**
     * Determine the main folder of the external SD card containing the given file.
     *
     * @param file the file.
     * @return The main folder of the external SD card containing this file, if the file is on an SD card. Otherwise,
     * null is returned.
     */
    @TargetApi(Build.VERSION_CODES.KITKAT)
    public static String getExtSdCardFolder(@NonNull final File file) {
        String[] extSdPaths = getExtSdCardPaths();
        try {
            for (String extSdPath : extSdPaths) {
                if (file.getCanonicalPath().startsWith(extSdPath)) {
                    return extSdPath;
                }
            }
        } catch (IOException e) {
            return null;
        }
        return null;
    }

    /**
     * Get a list of external SD card paths. (Kitkat or higher.)
     *
     * @return A list of external SD card paths.
     */
    @TargetApi(Build.VERSION_CODES.KITKAT)
    private static String[] getExtSdCardPaths() {
        List<String> paths = new ArrayList<>();
        for (File file : applicationContext.getExternalFilesDirs("external")) {
            if (file != null && !file.equals(applicationContext.getExternalFilesDir("external"))) {
                int index = file.getAbsolutePath().lastIndexOf("/Android/data");
                if (index < 0) {
                    Log.w("Uri", "Unexpected external file dir: " + file.getAbsolutePath());
                } else {
                    String path = file.getAbsolutePath().substring(0, index);
                    try {
                        path = new File(path).getCanonicalPath();
                    } catch (IOException e) {
                        // Keep non-canonical path.
                    }
                    paths.add(path);
                }
            }
        }
        return paths.toArray(new String[paths.size()]);
    }
}