Android读写文件

来源:互联网 发布:seo有哪些优化 编辑:程序博客网 时间:2024/04/30 03:04

1、resource中的raw文件夹中获取文件并读取数据(资源文件只能读不能写)

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的编码类型选择合适的编码,如果不调整会乱码   in.close();               }catch(Exception e){       e.printStackTrace();            } myTextView.setText(res);//把得到的内容显示在TextView上

2、asset中获取文件并读取数据(资源文件只能读不能写)

String fileName = "yan.txt"; //文件名字String res=""; try{    InputStream in = getResources().getAssets().open(fileName);   // \Test\assets\yan.txt这里有这样的文件存在   int length = in.available();         byte [] buffer = new byte[length];        in.read(buffer);            res = EncodingUtils.getString(buffer, "UTF-8");     }catch(Exception e){       e.printStackTrace();            }

3、      sdcard中去读文件,

首先要把文件通过\android-sdk-windows\tools\adb.exe把本地计算机上的文件copysdcard上去,adb.exe push e:/Y.txt /sdcard/,不可以用adb.exe push e:\Y.txt\sdcard\同样:把仿真器上的文件copy到本地计算机上用: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);  //用这个就不行了,必须用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);

3、写文件,一般写在\data\data\com.test\files\里面,

打开DDMS查看file explorer是可以看到仿真器文件存放目录的结构的

   String fileName = "TEST.txt";   String message = "FFFFFFF11111FFFFF" ;   <u>writeFileData</u>(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、  写、data/data/目录(相当AP工作目录)上的文件

openFileOutput

   //写文件在./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();        }    }//-------------------------------------------------------//读文件在./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;     }   

6、     写、sdcard目录上的文件

要用FileOutputStream不能用openFileOutput

 

    //写在/mnt/sdcard/目录下面的文件   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();        }    }    //读在/mnt/sdcard/目录下面的文件   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;    }

注:openFileOutput是在raw里编译过的,FileOutputStream是任何文件都可以

参考:http://dev.10086.cn/cmdn/wiki/index.php?doc-view-6017.html

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