SDUtil.java

package com.cheng.utils.file;

import android.os.Environment;
import android.os.StatFs;

import com.cheng.utils.Logger;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

/**
 * 针对SD操作相关的工具方法
 */
public class SDUtil {

    static {
        Logger.TAG = "SDUtil";
    }

    /**
     * 是否有SDCard
     * @return 是否有SDCard
     */
    public static boolean checkSDCardAvailable() {
        String status = Environment.getExternalStorageState();
        return status.equals(Environment.MEDIA_MOUNTED);
    }

    /**
     * 获取SD卡路径
     *
     * @return
     */
    public static String getSDCardPath() {
        return Environment.getExternalStorageDirectory().getAbsolutePath()
                + File.separator;
    }

    /**
     * 获取SD卡路径
     *
     * @return
     */
    public static String getSDCardPath(String dirName) {
        String path = getSDCardPath() + File.separator + dirName;
        File file = new File(path);
        if(!file.exists())
            file.mkdir();
        return file.getAbsolutePath();
    }

    /**
     * 获取SD卡的剩余容量 单位byte
     *
     * @return
     */
    public static long getSDCardAllSize() {
        if (checkSDCardAvailable()) {
            StatFs stat = new StatFs(getSDCardPath());
            // 获取空闲的数据块的数量
            long availableBlocks = (long) stat.getAvailableBlocks() - 4;
            // 获取单个数据块的大小（byte）
            long freeBlocks = stat.getAvailableBlocks();
            return freeBlocks * availableBlocks;
        }
        return 0;
    }

    /**
     * 获取指定路径所在空间的剩余可用容量字节数，单位byte
     *
     * @param filePath
     * @return 容量字节 SDCard可用空间，内部存储可用空间
     */
    public static long getFreeBytes(String filePath) {
        // 如果是sd卡的下的路径，则获取sd卡可用容量
        if (filePath.startsWith(getSDCardPath())) {
            filePath = getSDCardPath();
        } else {// 如果是内部存储的路径，则获取内存存储的可用容量
            filePath = Environment.getDataDirectory().getAbsolutePath();
        }
        StatFs stat = new StatFs(filePath);
        long availableBlocks = (long) stat.getAvailableBlocks() - 4;
        return stat.getBlockSize() * availableBlocks;
    }

    /**
     * 获取系统存储路径
     *
     * @return
     */
    public static String getRootDirectoryPath() {
        return Environment.getRootDirectory().getAbsolutePath();
    }

    /**
     * Check if the file is exists
     *
     * @param filePath 文件路径
     * @param fileName 文件名
     * @return 是否存在文件
     */
    public static boolean isFileExistsInSDCard(String filePath, String fileName) {
        boolean flag = false;
        if (checkSDCardAvailable()) {
            File file = new File(filePath, fileName);
            if (file.exists()) {
                flag = true;
            }
        }
        return flag;
    }

    /**
     * Write file to SD card
     *
     * @param filePath 文件路径
     * @param filename 文件名
     * @param content  内容
     * @return 是否保存成功
     * @throws Exception
     */
    public static boolean saveFileToSDCard(String filePath, String filename,
                                           String content) throws Exception {
        boolean flag = false;
        if (!checkSDCardAvailable()) return flag;
        File dir = new File(filePath);
        if (!dir.exists()) {
            dir.mkdir();
        }
        File file = new File(filePath, filename);
        FileOutputStream outStream = new FileOutputStream(file);
        outStream.write(content.getBytes());
        outStream.close();
        flag = true;
        return flag;
    }

    /**
     * Read file as stream from SD card
     *
     * @param fileName String PATH =
     *                 Environment.getExternalStorageDirectory().getAbsolutePath() +
     *                 "/dirName";
     * @return Byte数组
     */
    public static byte[] readFileFromSDCard(String filePath, String fileName) {
        byte[] buffer = null;
        try {
            if (checkSDCardAvailable()) {
                String filePaht = filePath + "/" + fileName;
                FileInputStream fin = new FileInputStream(filePaht);
                int length = fin.available();
                buffer = new byte[length];
                fin.read(buffer);
                fin.close();
            }
        } catch (Exception e) {
            Logger.e(e);
        }
        return buffer;
    }

    /**
     * Delete file
     *
     * @param filePath 文件路径
     * @param fileName filePath =
     *                 android.os.Environment.getExternalStorageDirectory().getPath()
     * @return 是否删除成功
     */
    public static boolean deleteSDFile(String filePath, String fileName) {
        File file = new File(filePath + "/" + fileName);
        if (!file.exists() || file.isDirectory())
            return false;
        return file.delete();
    }
}