Android讀寫文件

一、       從resource中的raw文件夾中獲取文件並讀取數據(資源文件隻能讀不能寫)
String res = "";

try{

InputStream in = getResources().openRawResource(R.raw.bbi);

//在\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");

   //依bbi.txt的編碼類型選擇合適的編碼,如果不調整會亂碼

   in.close();           

   }catch(Exception e){

      e.printStackTrace();        

   }

myTextView.setText(res);//把得到的內容顯示在TextView上

 

二、       從asset中獲取文件並讀取數據(資源文件隻能讀不能寫)
String fileName = "yan.txt"; //文件名字

String res="";

try{

   InputStream in = getResources().getAssets().open(fileName);

   // \Test\assets\yan.txt這裡有這樣的文件存在

   int length = in.available();        

byte [] buffer = new byte[length];       

in.read(buffer);           

res = EncodingUtils.getString(buffer, "UTF-8");    

}catch(Exception e){

      e.printStackTrace();        

   }

 

三、       從sdcard中去讀文件,首先要把文件通過\android-sdk-windows\tools\adb.exe把本地計算機上的文件copy到sdcard上去,adb.exe push e:/Y.txt /sdcard/, 不可以用adb.exe push e:\Y.txt \sdcard\同樣: 把仿真器上的文件copy到本地計算機上用: adb pull ./data/data/com.tt/files/Test.txt e:/
 

String fileName = "/sdcard/Y.txt";

//也可以用String fileName = "mnt/sdcard/Y.txt";

String res="";    

try{

FileInputStream fin = new FileInputStream(fileName);

//FileInputStream fin = openFileInput(fileName); 

//用這個就不行瞭,必須用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);

 

四、       寫文件, 一般寫在\data\data\com.test\files\裡面,打開DDMS查看file explorer是可以看到仿真器文件存放目錄的結構的
   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();

       }

   }   

 

五、       寫, 讀data/data/目錄(相當AP工作目錄)上的文件,用openFileOutput
   //寫文件在./data/data/com.tt/files/下面

   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();

       }

   }

//——————————————————-

//讀文件在./data/data/com.tt/files/下面

   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;

    }  

六、       寫, 讀sdcard目錄上的文件,要用FileOutputStream, 不能用openFileOutput
 

    //寫在/mnt/sdcard/目錄下面的文件

   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();

       }

   }

 

   //讀在/mnt/sdcard/目錄下面的文件

   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;

   }
作者:yilip

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