Android获取各种系统路径的方法
通过Environment获取的
- Environment.getDataDirectory().getPath() : 获得根目录/data 内部存储路径
- Environment.getDownloadCacheDirectory().getPath() : 获得缓存目录/cache
- Environment.getExternalStorageDirectory().getPath(): 获得SD卡目录/mnt/sdcard（获取的是手机外置sd卡的路径）
- Environment.getRootDirectory().getPath() : 获得系统目录/system
通过Context获取的
- Context.getDatabasePath() 返回通过Context.openOrCreateDatabase 创建的数据库文件
Context.getCacheDir().getPath() : 用于获取APP的cache目录/data/data//cache目录
Context.getExternalCacheDir().getPath() : 用于获取APP的在SD卡中的cache目录/mnt/sdcard/android/data//cache
Context.getFilesDir().getPath() : 用于获取APP的files目录 /data/data//files
Context.getObbDir().getPath(): 用于获取APPSDK中的obb目录/mnt/sdcard/Android/obb/
Context.getPackageName() : 用于获取APP的所在包目录
- Context.getPackageCodePath() : 来获得当前应用程序对应的 apk 文件的路径
- Context.getPackageResourcePath() : 获取该程序的安装包路径
完整 操作手机文件 工具类:
public void saveToPhone(View v) {
// FileDir();
SDCardTest();
}
private void FileDir() {
boolean mExternalStorageAvailable = false;
boolean mExternalStorageWriteable = false;
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
// We can read and write the media
mExternalStorageAvailable = mExternalStorageWriteable = true;
} else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
// We can only read the media
mExternalStorageAvailable = true;
mExternalStorageWriteable = false;
} else {
// Something else is wrong. It may be one of many other states, but all we need
// to know is we can neither read nor write
mExternalStorageAvailable = mExternalStorageWriteable = false;
}
Log.i("codecraeer", "getFilesDir = " + getFilesDir());
Log.i("codecraeer", "getExternalFilesDir = " + getExternalFilesDir("exter_test").getAbsolutePath());
Log.i("codecraeer", "getDownloadCacheDirectory = " + Environment.getDownloadCacheDirectory().getAbsolutePath());
Log.i("codecraeer", "getDataDirectory = " + Environment.getDataDirectory().getAbsolutePath());
Log.i("codecraeer", "getExternalStorageDirectory = " + Environment.getExternalStorageDirectory().getAbsolutePath());
Log.i("codecraeer", "getExternalStoragePublicDirectory = " + Environment.getExternalStoragePublicDirectory("pub_test"));
}
/** * SDcard操作 */
public void SDCardTest(){
try {
//获取扩展SD卡设备状态
String sDStateString = Environment.getExternalStorageState();
//拥有可读可写权限
if(sDStateString.equals(Environment.MEDIA_MOUNTED)){
//获取扩展存储设备的文件目录
File SDFile = Environment.getExternalStorageDirectory();
String fileDirectoryPath=SDFile.getAbsolutePath()+File.separator+"测试文件夹";
File fileDirectory=new File(fileDirectoryPath);
//打开文件
File myFile = new File(fileDirectoryPath+File.separator+"MyFile.txt");
//判断是否存在,不存在则创建
if (!fileDirectory.exists()) {
//按照指定的路径创建文件夹
fileDirectory.mkdirs();
}
if (!myFile.exists()) {
try {
//在指定的文件夹中创建文件
myFile.createNewFile();
} catch (Exception e) {
}
}
//写数据
String szOutText="Hello, World!+姚佳伟";
FileOutputStream outputStream=new FileOutputStream(myFile);
outputStream.write(szOutText.getBytes());
outputStream.close();
}
//拥有只读权限
else if(sDStateString.endsWith(Environment.MEDIA_MOUNTED_READ_ONLY)){
//获取扩展存储设备的文件目录
File SDFile=android.os.Environment.getExternalStorageDirectory();
//创建一个文件
File myFile=new File(SDFile.getAbsolutePath()+File.separator+"MyFile.txt");
//判断文件是否存在
if(myFile.exists()){
//读数据
FileInputStream inputStream=new FileInputStream(myFile);
byte[]buffer=new byte[1024];
inputStream.read(buffer);
inputStream.close();
}
}
} catch (IOException e) {
e.printStackTrace();
Log.d("yjw","检查权限");
}
}
public class FileUtils {
static String directoryPath = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "FileDemo" + File.separator;
String fileName = directoryPath + getISO8601TimeFileName() + ".txt";
//创建文件夹及文件
public void CreateText() throws IOException {
File file = new File(directoryPath);
if (!file.exists()) {
try {
//按照指定的路径创建文件夹
file.mkdirs();
} catch (Exception e) {
// TODO: handle exception
}
}
File dir = new File(fileName);
if (!dir.exists()) {
try {
//在指定的文件夹中创建文件
dir.createNewFile();
} catch (Exception e) {
}
}
}
//向已创建的文件中写入数据
public void print(String str) {
FileWriter fw = null;
BufferedWriter bw = null;
String datetime = "";
try {
CreateText();
SimpleDateFormat tempDate = new SimpleDateFormat("yyyy-MM-dd" + " " + "hh:mm:ss");
datetime = tempDate.format(new java.util.Date()).toString();
fw = new FileWriter(fileName, true);//
// 创建FileWriter对象，用来写入字符流
/** * 如果想要每次写入,清除之前的内容,使用FileOutputStream流 */
bw = new BufferedWriter(fw); // 将缓冲对文件的输出
String myreadline = datetime + "[]" + str;
bw.write(myreadline + "\n"); // 写入文件
bw.newLine();
bw.flush(); // 刷新该流的缓冲
bw.close();
fw.close();
} catch (IOException e) {
e.printStackTrace();
try {
bw.close();
fw.close();
} catch (IOException e1) {
}
}
}
/** * 此方法为android程序写入sd文件文件，用到了android-annotation的支持库@ * * @param buffer 写入文件的内容 * @param folder 保存文件的文件夹名称,如log；可为null，默认保存在sd卡根目录 * @param fileName 文件名称，默认app_log.txt * @param append 是否追加写入，true为追加写入，false为重写文件 * @param autoLine 针对追加模式，true为增加时换行，false为增加时不换行 */
public synchronized static void writeFiledToSDCard(@NonNull final byte[] buffer, @Nullable final String folder, @Nullable final String fileName, final boolean append, final boolean autoLine) {
new Thread(new Runnable() {
@Override
public void run() {
boolean sdCardExist = Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);
String folderPath = "";
if (sdCardExist) {
//TextUtils为android自带的帮助类
if (TextUtils.isEmpty(folder)) {
//如果folder为空，则直接保存在sd卡的根目录
// folderPath = Environment.getExternalStorageDirectory() + File.separator;
folderPath = directoryPath;
} else {
folderPath = Environment.getExternalStorageDirectory() + File.separator + folder + File.separator;
}
} else {
return;
}
File fileDir = new File(folderPath);
if (!fileDir.exists()) {
if (!fileDir.mkdirs()) {
return;
}
}
File file;
//判断文件名是否为空
if (TextUtils.isEmpty(fileName)) {
file = new File(folderPath + getISO8601TimeFileName() + ".txt");
} else {
file = new File(folderPath + fileName);
}
RandomAccessFile raf = null;
FileOutputStream out = null;
try {
if (append) {
//如果为追加则在原来的基础上继续写文件
raf = new RandomAccessFile(file, "rw");
raf.seek(file.length());
raf.write(buffer);
if (autoLine) {
raf.write("\n".getBytes());
}
} else {
//重写文件，覆盖掉原来的数据
out = new FileOutputStream(file);
out.write(buffer);
out.flush();
}
Log.d("yjw", "writeFiledToSDCard===" + "文件存入成功");
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (raf != null) {
raf.close();
}
if (out != null) {
out.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}).start();
}
public static String getISO8601TimeFileName() {
TimeZone tz = TimeZone.getTimeZone("Asia/Shanghai");
DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
df.setTimeZone(tz);
String nowAsISO = df.format(new Date());
return nowAsISO;
}
}参考资料:
