内部存储保存/读取数据
package com.allens.utils;
import android.content.Context;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import static android.content.Context.MODE_APPEND;
/**
* 描述:
* <p>
* Created by allens on 2017/12/26.
*/
public class FileCacheUtil {
private Context context;
private String mFileName = "message.txt";
private FileCacheUtil(Context context) {
this.context = context;
}
private static FileCacheUtil fileCacheUtil;
public static FileCacheUtil getInstance(Context context) {
if (fileCacheUtil == null) {
synchronized (FileCacheUtil.class) {
if (fileCacheUtil == null) {
fileCacheUtil = new FileCacheUtil(context);
}
}
}
return fileCacheUtil;
}
public String read() {
try {
FileInputStream inStream = context.openFileInput(mFileName);
byte[] buffer = new byte[1024];
int hasRead = 0;
StringBuilder sb = new StringBuilder();
while ((hasRead = inStream.read(buffer)) != -1) {
sb.append(new String(buffer, 0, hasRead));
}
inStream.close();
return sb.toString();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public void write(String msg) {
if (msg == null) {
return;
}
try {
FileOutputStream fos = context.openFileOutput(mFileName, MODE_APPEND);
fos.write(msg.getBytes());
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
外部存储保存/读取数据
package com.allens.utils;
import android.content.Context;
import android.os.Environment;
import android.os.StatFs;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* 判断ＳＤ卡是否挂载
* 获取ＳＤ卡的根目录
* 获取ＳＤ卡总容量
* 获取ＳＤ卡剩余容量
* 向ＳＤ卡９大共有目录保存数据
* 向ＳＤ卡私有File目录写入数据
* 向ＳＤ卡私有Cache目录写入数据
* 从ＳＤ卡中读取数据
*/
public class SDUtils {
/**
* 判断ＳＤ卡是否挂载
*
* @return
*/
public static boolean isSDCardMounted() {
String state = Environment.getExternalStorageState();
return state.equals(Environment.MEDIA_MOUNTED);
}
/**
* @return 返回ＳＤ卡根目录
*/
public static String getSDCardRootDir() {
return Environment.getExternalStorageDirectory().getPath();
}
/***
*
* @return 获取ＳＤ卡总容量 返回ＭＢ
*/
public static long getSDCardTotalSize() {
if (isSDCardMounted()) {
//StatFs Statistic File System 簇
StatFs sf = new StatFs(getSDCardRootDir());
int blockSize = sf.getBlockSize();
int blockCount = sf.getBlockCount();
return blockSize * blockCount / 1024 / 1024;
}
return 0;
}
/**
* @return 获取ＳＤ卡可用容量 返回ＭＢ
*/
public static long getSDCardAvailableSize() {
if (isSDCardMounted()) {
StatFs sf = new StatFs(getSDCardRootDir());
int availableBlockCount = sf.getAvailableBlocks();
int blockSize = sf.getBlockSize();
return availableBlockCount * blockSize / 1024 / 1024;
}
return 0;
}
/**
* 向ＳＤ卡９大共有目录保存数据
*
* @param data 需要保存的数据
* @param type 区分９大共有目录的type
* @param fileName 另存为的文件名称
* @return
*/
public static boolean saveFileToPublicDirectory(byte[] data,
String type, String fileName) {
if (isSDCardMounted()) {
BufferedOutputStream bos = null;
File fileDir =
Environment.getExternalStoragePublicDirectory(type);
File file = new File(fileDir, fileName);
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
bos = new BufferedOutputStream(new FileOutputStream(file));
bos.write(data);
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卡私有File目录写入数据
*
* @param context 上下文，用来找到storage/sdcard0/Android/data/packageName/files
* @param data 需要保存的数据
* @param fileName 另存为的文件名名称
* @return
*/
public static boolean saveFileToExternalFileDir(Context context, byte[] data, String fileName) {
if (isSDCardMounted()) {
BufferedOutputStream bos = null;
File fileDir = context.getExternalFilesDir(null);
File file = new File(fileDir, fileName);
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
bos = new BufferedOutputStream(new FileOutputStream(file));
bos.write(data);
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卡私有Cache目录写入数据
*
* @param context 上下文，用来找到storage/sdcard0/Android/data/packageName/cache
* @param data 需要保存的数据
* @param fileName 另存为的文件名名称
* @return
*/
public static boolean saveFileToExternalCacheDir(Context context, byte[] data,
String fileName) {
if (isSDCardMounted()) {
BufferedOutputStream bos = null;
File fileDir = context.getExternalCacheDir();
File file = new File(fileDir, fileName);
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
bos = new BufferedOutputStream(new FileOutputStream(file));
bos.write(data);
bos.flush();
return true;
} catch (Exception e) {
e.printStackTrace();
} finally {
if (bos != null) {
try {
bos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
return false;
}
/**
* 从ＳＤ卡中读取数据
*
* @param fileAbsolutePath 读取文件的绝对路径
* @return
*/
public static byte[] loadDataFromSDCard(String fileAbsolutePath) {
if (isSDCardMounted()) {
BufferedInputStream bis = null;
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try {
bis = new BufferedInputStream(
new FileInputStream(fileAbsolutePath));
byte[] buffer = new byte[1024 * 8];
int len = 0;
while ((len = bis.read(buffer)) != -1) {
baos.write(buffer, 0, len);
baos.flush();
}
return baos.toByteArray();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (bis != null) {
bis.close();
}
if (baos != null) {
baos.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
public static String getSDCardCacheDir(Context context) {
return context.getExternalCacheDir().getPath();
}
}
