Android 檔案讀寫工具類

標籤：

自己寫的工具類，寫的不好，慢慢修改。

記得加上許可權
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

package com.sy.utils;import android.content.Context;import android.os.Environment;import android.os.StatFs;import android.util.Log;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;/** * Created by SY on 2016/5/9. * 檔案讀寫工具類 */public class FileUtils {    private Context context;    private String SDCardPath = Environment.getExternalStorageDirectory().getAbsolutePath();//sd卡路徑    private static String SDState = Environment.getExternalStorageState();//SD卡狀態    public FileUtils(Context context) {        this.context = context;    }    /**     * 檔案儲存體到/data/data/<packagename>/files/預設目錄下     *     * @param fileName     * @param bytes     * @return     */    public boolean write2CacheFile(String fileName, byte[] bytes) {        FileOutputStream out = null;        BufferedOutputStream bos = null;        try {            out = context.openFileOutput(fileName, Context.MODE_PRIVATE);            bos = new BufferedOutputStream(out);            bos.write(bytes);            bos.flush();            return true;        } catch (Exception e) {            e.printStackTrace();        } finally {            if (bos != null) {                try {                    bos.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }        return false;    }    /**     * 向SD卡裡寫位元組     *     * @param path 檔案夾目錄     * @param file 檔案名稱     * @param data 寫入的位元組數組     * @return     */    public static boolean writeBytes(String path, String file, byte[] data) {        FileOutputStream fos = null;        try {            // 擁有足夠的容量            if (data.length < getSDFreeSize()) {                createDirectoryIfNotExist(path);                createFileIfNotExist(path + file);                fos = new FileOutputStream(path + File.separator + file);                fos.write(data);                fos.flush();                return true;            }        }catch (Exception e){            Log.e("writeBytes", e.getMessage());        }finally {            if (fos != null) {                try {                    fos.close();                } catch (IOException e) {                    e.printStackTrace();                }            }            return false;        }    }    /**     * 從SD卡裡讀取位元組數組     *     * @param path     目錄     * @param fileName 檔案名稱     * @return 返回位元組數組，檔案不存在返回null     */    public static byte[] readBytes(String path, String fileName) {        File file = new File(path + File.separator + fileName);        if (!file.exists()) {            return null;        }        InputStream inputStream = null;        try {            inputStream = new BufferedInputStream(new FileInputStream(file));            byte[] data = new byte[inputStream.available()];            inputStream.read(data);            return data;        } catch (IOException e) {            e.printStackTrace();        } finally {            try {                if (inputStream != null) {                    inputStream.close();                }            } catch (IOException e) {                e.printStackTrace();            }        }        return null;    }    /**     * 將一個位元組流寫入到SD卡檔案     *     * @param path     目錄路徑     * @param fileName 檔案名稱     * @param input    位元組流     * @return     */    public static Boolean write2SDFromInput(String path, String fileName, InputStream input) {        File file = null;        OutputStream output = null;        try {            int size = input.available();            // 擁有足夠的容量            if (size < getSDFreeSize()) {                createDirectoryIfNotExist(path);                createFileIfNotExist(path + File.separator + fileName);                file = new File(path + File.separator + fileName);                output = new BufferedOutputStream(new FileOutputStream(file));                byte buffer[] = new byte[1024];                int temp;                while ((temp = input.read(buffer)) != -1) {                    output.write(buffer, 0, temp);                }                output.flush();                return true;            }        } catch (IOException e1) {            e1.printStackTrace();        } finally {            try {                if (output != null) {                    output.close();                }            } catch (Exception e) {                e.printStackTrace();            }        }        return false;    }    /**     * 判斷SD卡是否存在     *     * @ return     */    private static boolean SDCardisExist() {        if (SDState.equals(Environment.MEDIA_MOUNTED)) {            return true;        } else            return false;    }    /**     * 擷取SD卡剩餘容量大小（單位Byte）     *     * @return     */    public static long getSDFreeSize() {        //取得SD卡檔案路徑        File path = Environment.getExternalStorageDirectory();        StatFs sf = new StatFs(path.getPath());        //擷取單個資料區塊的大小(Byte)        long blockSize = sf.getBlockSize();        //閒置資料區塊的數量        long freeBlocks = sf.getAvailableBlocks();        //返回SD卡空閑大小        return freeBlocks * blockSize;  //單位Byte        //return (freeBlocks * blockSize)/1024;   //單位KB//        return (freeBlocks * blockSize) / 1024 / 1024; //單位MB    }    /**     * 擷取SD卡總容量大小（單位Byte）     *     * @return     */    public static long getSDAllSize() {        //取得SD卡檔案路徑        File path = Environment.getExternalStorageDirectory();        StatFs sf = new StatFs(path.getPath());        //擷取單個資料區塊的大小(Byte)        long blockSize = sf.getBlockSize();        //擷取所有資料區塊數        long allBlocks = sf.getBlockCount();        //返回SD卡大小        return allBlocks * blockSize; //單位Byte        //return (allBlocks * blockSize)/1024; //單位KB//        return (allBlocks * blockSize) / 1024 / 1024; //單位MB    }    /**     * 如果目錄不存在，就建立目錄     *     * @param path 目錄     * @return     */    public static boolean createDirectoryIfNotExist(String path) {        File file = new File(path);        //如果檔案夾不存在則建立        if (!file.exists() && !file.isDirectory()) {            return file.mkdirs();        } else {            Log.e("目錄", "目錄存在！");            return false;        }    }    /**     * 如果檔案不存在，就建立檔案     * @param path 檔案路徑     * @return     */    public static boolean createFileIfNotExist(String path) {        File file = new File(path);        try {            if (!file.exists()) {                return file.createNewFile();            } else {                Log.e("檔案", "檔案存在！");                return false;            }        } catch (Exception e) {            Log.e("error", e.getMessage());            return false;        }    }}

Android 檔案讀寫工具類