万能存储工具类 SDCard存储  /data/data/存储  assets存储 raw存储

 粘贴过去就能够用了

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

    <!-- SDCard中创建与删除文件权限 -->
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
    <!-- 向SDCard写入数据权限 -->

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


package com.hexun.util;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;

import org.apache.http.util.EncodingUtils;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Environment;
import android.util.Log;

/**
 * 保存图片的类
 *
 *
 */
public class FileUtil {

    private final static String CACHE = "/image";
    private final static String CHARSETNAME = "UTF-8";

    /*************************** 从resource的raw中读取文件数据 *****************************************************/

    /**
     * raw中读取文件数据
     *
     * @param context
     * @param fileName
     *            R.raw.test
     * @return String 文件内容
     */
    public static String readRaw(Context context, int fileName) {
        try {
            // 得到资源中的Raw数据流
            InputStream in = context.getResources().openRawResource(fileName);
            return readInToStr(in);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /*************************** 从resource的asset中读取文件数据 **************************************************/

    /**
     * asset中读取文件数据
     *
     * @param context
     * @param fileName
     *            文件名称
     * @return String 文件内容
     */
    public static String readAssets(Context context, String fileName) {
        try {
            if (isNullEmptyBlank(fileName)) {
                return null;
            }
            // 得到资源中的asset数据流
            InputStream in = context.getResources().getAssets().open(fileName);
            return readInToStr(in);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /***************************** data/data/ *****************************************************************/

    // MODE_PRIVATE 私有(仅仅能创建它的应用訪问) 反复写入时会文件覆盖
    // MODE_APPEND 私有 反复写入时会在文件的末尾进行追加。而不是覆盖掉原来的文件
    // MODE_WORLD_READABLE 公用 可读
    // MODE_WORLD_WRITEABLE 公用 可读写
    /**
     * 写数据/data/data/
     *
     * @param context
     * @param fileName
     *            文件名称
     * @param str
     *            数据内容
     * @return 成功 false
     */
    public static boolean saveDataStr(Context context, String fileName,
            String writeStr) {
        if (isNullEmptyBlank(fileName) || isNullEmptyBlank(writeStr)) {
            try {
                String path = context.getFilesDir().getAbsolutePath();
                File file = new File(path, fileName);
                if (file.exists()) {
                    file.delete();
                }
                OutputStream os = new FileOutputStream(file);
                return saveOuToStr(writeStr, os);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return true;
    }

    /**
     * 读数据/data/data/
     *
     * @param context
     * @param fileName
     *            文件名称
     * @return String 文件内容
     */
    public static String readDataStr(Context context, String fileName) {
        if (isNullEmptyBlank(fileName)) {
            try {
                String path = context.getFilesDir().getAbsolutePath();
                File file = new File(path, fileName);
                if (file.exists()) {
                    InputStream in = new FileInputStream(file);
                    return readInToStr(in);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /***************************** /data/data/图片 ************************************************************/

    /**
     * /data/data/存储图片
     *
     * @param context
     * @param bitmap
     * @param imageName
     *            图片名
     * @return 成功 false
     */
    public static boolean saveDataImage(Context context, Bitmap bitmap,
            String imageName) {
        if (bitmap != null || isNullEmptyBlank(imageName)) {
            try {
                String path = context.getFilesDir().getAbsolutePath();
                File file = new File(path, imageName);
                if (file.exists()) {
                    file.delete();
                }
                OutputStream os = new FileOutputStream(file);
                return saveOuToImage(bitmap, os);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return true;
    }

    /**
     * /data/data/读取图片
     *
     * @param context
     * @param imageName
     * @return Bitmap
     */
    public static Bitmap readDataImage(Context context, String imageName) {
        if (isNullEmptyBlank(imageName)) {
            try {
                String path = context.getFilesDir().getAbsolutePath();
                File file = new File(path, imageName);
                if (file.exists()) {
                    InputStream in = new FileInputStream(file);
                    return BitmapFactory.decodeStream(in);
                }
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /***************************** SDCard数据 *****************************************************************/

    /**
     * 写数据SDCard
     *
     * @param fileName
     *            文件名称
     * @param writeStr
     *            数据内容
     * @return 成功 false
     */
    public static boolean saveSDStr(String fileName, String writeStr) {
        if (isNullEmptyBlank(fileName) || isNullEmptyBlank(writeStr)) {
            try {
                File file = new File(isExistsFilePath(), fileName);
                if (file.exists()) {// 判读文件是否存在。存在读取
                    file.delete();
                }
                OutputStream os = new FileOutputStream(file);
                return saveOuToStr(writeStr, os);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return true;
    }

    /**
     * 读取SDCard文件
     *
     * @param fileName
     *            文件名称
     * @return String 文件内容
     */
    @SuppressLint("SdCardPath")
    public static String readSDStr(String fileName) {
        if (isNullEmptyBlank(fileName)) {
            try {
                String filePath = isExistsFilePath() + "/";// "/mnt/sdcard/image/"+
                File file = new File(filePath);
                if (file.exists()) {// 判读文件是否存在,存在读取
                    InputStream fin = new FileInputStream(filePath + fileName);
                    return readInToStr(fin);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /***************************** SDCard图片 *****************************************************************/

    /**
     * 保存到SDCard
     *
     * @param bitmap
     * @param imageName
     *            图片名
     * @return 成功 false
     */
    public static boolean saveSDImage(Bitmap bitmap, String imageName) {
        if (isNullEmptyBlank(imageName) || bitmap != null) {
            try {
                File file = new File(isExistsFilePath(), imageName);
                if (file.exists()) {// 判读文件是否存在,存在读取
                    file.delete();
                }
                OutputStream fos = new FileOutputStream(file);
                return saveOuToImage(bitmap, fos);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return true;
    }

    /**
     * 获取SDCard文件
     *
     * @param imageName
     *            图片名
     * @return Bitmap
     */
    public static Bitmap readSDImage(String imageName) {
        if (isNullEmptyBlank(imageName)) {
            String filePath = getSDPath() + CACHE + "/" + imageName;
            File file = new File(filePath);
            if (file.exists()) {// 判读文件是否存在,存在读取
                return BitmapFactory.decodeFile(filePath);
            }
        }
        return null;
    }

    /***************************** 读取网络数据 *****************************************************************/

    /**
     * 读取网络数据
     *
     * @param path
     * @return String
     */
    public static String getNetFileString(String path) {
        try {
            URL url = new URL(path);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(5 * 1000);
            conn.setRequestMethod("GET");
            if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                InputStream inStream = conn.getInputStream();
                return readData(inStream, CHARSETNAME);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    private static String readData(InputStream inSream, String charsetName)
            throws Exception {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[4096];
        int len = -1;
        while ((len = inSream.read(buffer)) != -1) {
            outStream.write(buffer, 0, len);
        }
        byte[] data = outStream.toByteArray();
        outStream.close();
        inSream.close();
        return new String(data, charsetName);
    }

    /***************************** 网络读取图片byte[] *****************************************************************/

    /**
     *
     * @param path
     *            文件路径
     * @return byte[] data
     */
    public static byte[] getNetImageByte(String path) {
        try {
            URL url = new URL(path);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(5 * 1000);
            conn.setRequestMethod("GET");
            if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                InputStream inStream = conn.getInputStream();
                return readStream(inStream);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    private static byte[] readStream(InputStream inStream) throws Exception {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[4096];
        int len = 0;
        while ((len = inStream.read(buffer)) != -1) {
            outStream.write(buffer, 0, len);
        }
        outStream.close();
        inStream.close();
        return outStream.toByteArray();
    }

    /**
     * 获取sd卡的缓存路径, 一般在卡中sdCard就是这个文件夹
     *
     * @return SDPath
     */
    private static String getSDPath() {
        File sdDir = null;
        boolean sdCardExist = Environment.getExternalStorageState().equals(
                android.os.Environment.MEDIA_MOUNTED); // 推断sd卡是否存在
        if (sdCardExist) {
            sdDir = Environment.getExternalStorageDirectory();// 获取根文件夹
        } else {
            Log.e("ERROR", "没有内存卡");
        }
        return sdDir.toString();
    }

    /**
     * 获取缓存文件夹文件夹 假设不存在创建 否则则创建文件夹
     *
     * @return filePath
     */
    private static String isExistsFilePath() {
        String filePath = getSDPath() + CACHE;
        File file = new File(filePath);
        if (!file.exists()) {
            file.mkdirs();
        }
        return filePath;
    }

    private static boolean saveOuToStr(String writeStr, OutputStream os)
            throws IOException, UnsupportedEncodingException {
        os.write(writeStr.getBytes(CHARSETNAME));
        os.flush();
        os.close();
        return false;
    }

    private static String readInToStr(InputStream in) throws IOException {
        int length = in.available();
        byte[] buffer = new byte[length];
        in.read(buffer);
        in.close();
        return EncodingUtils.getString(buffer, CHARSETNAME);
    }

    private static boolean saveOuToImage(Bitmap bitmap, OutputStream fos)
            throws IOException {
        bitmap.compress(Bitmap.CompressFormat.PNG, 90, fos);
        fos.flush();
        fos.close();
        return false;
    }

    /**
     * 推断字符串是否为空(包括null与"","    ")
     *
     * @param str
     * @return true 包括null与"","    "
     */
    private static boolean isNullEmptyBlank(String str) {
        if (str == null || "".equals(str) || "".equals(str.trim())) {
            return false;
        }
        return true;
    }

}