Android read write file method summary

1. Get files from the raw folder in resource and read the data (resource files can only be read but not written)

String res = "";
try{
InputStream in = getResources().openRawResource(R.raw.bbi);
// in \Test\res\raw\bbi.txt,
int length = in.available();
byte [] buffer = new byte[length];
in.read(buffer);
//res = EncodingUtils.getString(buffer, "UTF-8");
//res = EncodingUtils.getString(buffer, "UNICODE");
res = EncodingUtils.getString(buffer, "BIG5");
// In accordance with the bbi.txt The encoding type to select the appropriate encoding, if not adjusted will be garbled 
in.close();
}catch(Exception e){
e.printStackTrace();
}

myTextView. setText (res); // displays the resulting content on TextView

2. Get files from asset and read data (resource files can only be read but not written)

String fileName = "yan.txt"; // The file name 
String res="";
try{
InputStream in = getResources().getAssets().open(fileName);
// \Test\assets\yan.txt There are files like this 
int length = in.available();
byte [] buffer = new byte[length];
in.read(buffer);
res = EncodingUtils.getString(buffer, "UTF-8");
}catch(Exception e){
e.printStackTrace();
}

3. To read the file from sdcard, first transfer the file from the local computer to sdcard via android-sdk-windows \tools\ adb. exe adb.push e:/ Y.txt /sdcard/, adb.exe push e:\ Y.txt \sdcard\ same: copy files from the emulator to the local computer: adb pull. / data data/com. tt/files/Test txt e: /

String fileName = "/sdcard/Y.txt";
// You can also use String fileName = "mnt/sdcard/Y.txt";
String res="";
try{
FileInputStream fin = new FileInputStream(fileName);
//FileInputStream fin = openFileInput(fileName);
// I can't use that. I have to FileInputStream
int length = fin.available();
byte [] buffer = new byte[length];
fin.read(buffer);
res = EncodingUtils.getString(buffer, "UTF-8");
fin.close();
}catch(Exception e){
e.printStackTrace();
}
myTextView.setText(res);

4. Write the file, 1 in \data\data\ com. test\files\, open DDMS to see file explorer, you can see the file directory structure of the simulator

String fileName = "TEST.txt";
String message = "FFFFFFF11111FFFFF" ;
writeFileData(fileName, message);
public voidwriteFileData(String fileName,String message){
try{
FileOutputStream fout =openFileOutput(fileName, MODE_PRIVATE);
byte [] bytes = message.getBytes();
fout.write(bytes);
fout.close();
}
catch(Exception e){
e.printStackTrace();
}
}

5. Write and read files in data/data/ directory (equivalent to AP working directory) using openFileOutput

// Write the file in ./data/data/com.tt/files/ The following 
public voidwriteFileData(String fileName,String message){
try{
FileOutputStream fout =openFileOutput(fileName, MODE_PRIVATE);
byte [] bytes = message.getBytes();
fout.write(bytes);
fout.close();
}
catch(Exception e){
e.printStackTrace();
}
}
//-------------------------------------------------------
// Read the file in ./data/data/com.tt/files/ The following 
public String readFileData(String fileName){
String res="";
try{
FileInputStream fin = openFileInput(fileName);
int length = fin.available();
byte [] buffer = new byte[length];
fin.read(buffer);
res = EncodingUtils.getString(buffer, "UTF-8");
fin.close();
}
catch(Exception e){
e.printStackTrace();
}
return res;
}

6. Write and read files in the sdcard directory. Use FileOutputStream, not openFileOutput

// Written in the book /mnt/sdcard/ The files under the directory 
public voidwriteFileSdcard(String fileName,String message){
try{
//FileOutputStream fout = openFileOutput(fileName, MODE_PRIVATE);
FileOutputStream fout = newFileOutputStream(fileName);
byte [] bytes = message.getBytes();
fout.write(bytes);
fout.close();
}
catch(Exception e){
e.printStackTrace();
}
}
// Read in /mnt/sdcard/ The files under the directory 
public String readFileSdcard(String fileName){
String res="";
try{
FileInputStream fin = new FileInputStream(fileName);
int length = fin.available();
byte [] buffer = new byte[length];
fin.read(buffer);
res = EncodingUtils.getString(buffer, "UTF-8");
fin.close();
}
catch(Exception e){
e.printStackTrace();
}
return res;
}

Note: openFileOutput is compiled in raw. FileOutputStream is any file