Android讀寫文件

一、  從 resource 中的 raw 文件夾中獲取文件並讀取數據（資源文件只能讀不能寫）

String res = "";

 

try{

 

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

 

//在\Test\res\raw\bbi.txt,

 

   intlength = in.available();      

 

   byte[] buffer = newbyte[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（資源文件只能讀不能寫）

   

String fileName = "yan.txt";//文件名字

 

String res="";

 

try{

 

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

 

   // \Test\assets\yan.txt這裏有這樣的文件存在

 

   intlength = in.available();        

 

byte[] buffer = newbyte[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:/Y.txt /sdcard/

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

 

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

 

String res="";    

 

try{

 

FileInputStream fin = newFileInputStream(fileName);

 

//FileInputStream fin = openFileInput(fileName); 

 

//用這個就不行了，必須用FileInputStream

 

    intlength = fin.available();

 

    byte[] buffer = newbyte[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\裏面，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);

 

   

 

   publicvoidwriteFileData(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

 

   publicvoidwriteFileData(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

 

   publicString readFileData(String fileName){

 

        String res="";

 

        try{

 

         FileInputStream fin = openFileInput(fileName);

 

         intlength = fin.available();

 

         byte[] buffer = newbyte[length];

 

         fin.read(buffer);    

 

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

 

         fin.close();    

 

        }

 

        catch(Exception e){

 

         e.printStackTrace();

 

        }

 

        returnres;

 

    }  







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

 

   publicvoidwriteFileSdcard(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

 

   publicString readFileSdcard(String fileName){

 

        String res="";

 

        try{

 

         FileInputStream fin = newFileInputStream(fileName);

 

         intlength = fin.available();

 

         byte[] buffer = newbyte[length];

 

         fin.read(buffer);    

 

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

 

         fin.close();    

 

        }

 

        catch(Exception e){

 

         e.printStackTrace();

 

        }

 

        returnres;

 

   }