1、获得系统根目录：
public String getDirPath(){
return Environment.getExternalStorageDirectory().getAbsolutePath();
}
2、创建目录：
public void mkdir(Context context, String path){
File filePath = new File(path);
if(!filePath.exists()){
if(!filePath.mkdirs())
Toast.makeText(context,"创建目录失败", Toast.LENGTH_LONG).show();
}
}
3、创建文件：
public void createFile(String filePath){
File file = new File(filePath);
if(！file.exists()){
try{
file.createNewFile();
}catch(IOException e){
}
}
}
4、写操作
/**
* 在指定位置写
* @param filename
* @param skipBytes
* @param data
* @return
*/
public static boolean writeData(String filepath,long skipBytes, String data){
boolean result = false;
File file = new File(filepath);
try{
RandomAccessFile rFile;
if(file.exists()){
rFile = new RandomAccessFile(file, "rw");
rFile.seek(skipBytes);
rFile.write(data.getBytes());
rFile.close();
rFile = null;
result = true;
}
}catch(Exception e){
// return result;
}
return result;
}
5、读操作
/**
* 读取指定位置的数据
* @param filename
* @param offset
* @param readlen
* @return
*/
public String ReadData(String filename, long offset, int readlen){
String res="";
File file = new File(filename);
long fileLen = 0;
try{
RandomAccessFile rFile;
if(file.exists()){
rFile = new RandomAccessFile(file, "rw");
fileLen = rFile.length();
if(fileLen > offset+1){//读取位置必须在文件大小内
rFile.seek(offset);
byte[] data = new byte[readlen];
rFile.read(data);
res = EncodingUtils.getString(data, 0, readlen, "UTF-8");
}
rFile.close();
rFile = null;
}
}catch (Exception e) {
// TODO: handle exception
}
return res;
}